php-cimage/CImage.php

<?php
/**
 * Resize and crop images on the fly, store generated images in a cache.
 *
 * @author Mikael Roos mos@dbwebb.se
 * @example http://dbwebb.se/opensource/cimage
 * @link https://github.com/mosbth/cimage
 */
class CImage
{

    /**
     * Constants type of PNG image
     */
    const PNG_GREYSCALE         = 0;
    const PNG_RGB               = 2;
    const PNG_RGB_PALETTE       = 3;
    const PNG_GREYSCALE_ALPHA   = 4;
    const PNG_RGB_ALPHA         = 6;



    /**
     * Constant for default image quality when not set
     */
    const JPEG_QUALITY_DEFAULT = 60;



    /**
     * Quality level for JPEG images.
     */
    private $quality;



    /**
     * Is the quality level set from external use (true) or is it default (false)?
     */
    private $useQuality = false;



    /**
     * Constant for default image quality when not set
     */
    const PNG_COMPRESSION_DEFAULT = -1;



    /**
     * Compression level for PNG images.
     */
    private $compress;



    /**
     * Is the compress level set from external use (true) or is it default (false)?
     */
    private $useCompress = false;




    /**
     * Default background color, red, green, blue, alpha.
     *
     * @todo remake when upgrading to PHP 5.5
     */
    /*
    const BACKGROUND_COLOR = array(
        'red'   => 0,
        'green' => 0,
        'blue'  => 0,
        'alpha' => null,
    );*/



    /**
     * Default background color to use.
     *
     * @todo remake when upgrading to PHP 5.5
     */
    //private $bgColorDefault = self::BACKGROUND_COLOR;
    private $bgColorDefault = array(
        'red'   => 0,
        'green' => 0,
        'blue'  => 0,
        'alpha' => null,
    );


    /**
     * Background color to use, specified as part of options.
     */
    private $bgColor;



    /**
     * Where to save the target file.
     */
    private $saveFolder;



    /**
     * The working image object.
     */
    private $image;



    /**
     * The root folder of images (only used in constructor to create $pathToImage?).
     */
    private $imageFolder;



    /**
     * Image filename, may include subdirectory, relative from $imageFolder
     */
    private $imageSrc;



    /**
     * Actual path to the image, $imageFolder . '/' . $imageSrc
     */
    private $pathToImage;



    /**
     * Original file extension
     */
    private $fileExtension;



    /**
     * File extension to use when saving image.
     */
    private $extension;



    /**
     * Output format, supports null (image) or json.
     */
    private $outputFormat = null;



    /**
     * Verbose mode to print out a trace and display the created image
     */
    private $verbose = false;



    /**
     * Keep a log/trace on what happens
     */
    private $log = array();



    /**
     * Handle image as palette image
     */
    private $palette;



    /**
     * Target filename, with path, to save resulting image in.
     */
    private $cacheFileName;



    /**
     * Set a format to save image as, or null to use original format.
     */
    private $saveAs;


    /**
     * Path to command for filter optimize, for example optipng or null.
     */
    private $pngFilter;



    /**
     * Path to command for deflate optimize, for example pngout or null.
     */
    private $pngDeflate;



    /**
     * Path to command to optimize jpeg images, for example jpegtran or null.
     */
    private $jpegOptimize;


    /**
     * Image dimensions, calculated from loaded image.
     */
    private $width;  // Calculated from source image
    private $height; // Calculated from source image


    /**
     * New image dimensions, incoming as argument or calculated.
     */
    private $newWidth;
    private $newWidthOrig;  // Save original value
    private $newHeight;
    private $newHeightOrig; // Save original value


    /**
     * Change target height & width when different dpr, dpr 2 means double image dimensions.
     */
    private $dpr = 1;


    /**
     * Always upscale images, even if they are smaller than target image.
     */
    const UPSCALE_DEFAULT = true;
    private $upscale = self::UPSCALE_DEFAULT;



    /**
     * Array with details on how to crop, incoming as argument and calculated.
     */
    public $crop;
    public $cropOrig; // Save original value


    /**
     * String with details on how to do image convolution. String
     * should map a key in the $convolvs array or be a string of
     * 11 float values separated by comma. The first nine builds
     * up the matrix, then divisor and last offset.
     */
    private $convolve;


    /**
     * Custom convolution expressions, matrix 3x3, divisor and offset.
     */
    private $convolves = array(
        'lighten'       => '0,0,0, 0,12,0, 0,0,0, 9, 0',
        'darken'        => '0,0,0, 0,6,0, 0,0,0, 9, 0',
        'sharpen'       => '-1,-1,-1, -1,16,-1, -1,-1,-1, 8, 0',
        'sharpen-alt'   => '0,-1,0, -1,5,-1, 0,-1,0, 1, 0',
        'emboss'        => '1,1,-1, 1,3,-1, 1,-1,-1, 3, 0',
        'emboss-alt'    => '-2,-1,0, -1,1,1, 0,1,2, 1, 0',
        'blur'          => '1,1,1, 1,15,1, 1,1,1, 23, 0',
        'gblur'         => '1,2,1, 2,4,2, 1,2,1, 16, 0',
        'edge'          => '-1,-1,-1, -1,8,-1, -1,-1,-1, 9, 0',
        'edge-alt'      => '0,1,0, 1,-4,1, 0,1,0, 1, 0',
        'draw'          => '0,-1,0, -1,5,-1, 0,-1,0, 0, 0',
        'mean'          => '1,1,1, 1,1,1, 1,1,1, 9, 0',
        'motion'        => '1,0,0, 0,1,0, 0,0,1, 3, 0',
    );


    /**
     * Resize strategy to fill extra area with background color.
     * True or false.
     */
    private $fillToFit;


    /**
     * Used with option area to set which parts of the image to use.
     */
    private $offset;



    /**
    * Calculate target dimension for image when using fill-to-fit resize strategy.
    */
    private $fillWidth;
    private $fillHeight;



    /**
    * Allow remote file download, default is to disallow remote file download.
    */
    private $allowRemote = false;



    /**
     * Pattern to recognize a remote file.
     */
    //private $remotePattern = '#^[http|https]://#';
    private $remotePattern = '#^https?://#';



    /**
     * Use the cache if true, set to false to ignore the cached file.
     */
    private $useCache = true;


    /**
     * Properties, the class is mutable and the method setOptions()
     * decides (partly) what properties are created.
     *
     * @todo Clean up these and check if and how they are used
     */

    public $keepRatio;
    public $cropToFit;
    private $cropWidth;
    private $cropHeight;
    public $crop_x;
    public $crop_y;
    public $filters;
    private $type; // Calculated from source image
    private $attr; // Calculated from source image
    private $useOriginal; // Use original image if possible




    /**
     * Constructor, can take arguments to init the object.
     *
     * @param string $imageSrc    filename which may contain subdirectory.
     * @param string $imageFolder path to root folder for images.
     * @param string $saveFolder  path to folder where to save the new file or null to skip saving.
     * @param string $saveName    name of target file when saveing.
     */
    public function __construct($imageSrc = null, $imageFolder = null, $saveFolder = null, $saveName = null)
    {
        $this->setSource($imageSrc, $imageFolder);
        $this->setTarget($saveFolder, $saveName);
    }



    /**
     * Set verbose mode.
     *
     * @param boolean $mode true or false to enable and disable verbose mode,
     *                      default is true.
     *
     * @return $this
     */
    public function setVerbose($mode = true)
    {
        $this->verbose = $mode;
        return $this;
    }



    /**
     * Set save folder, base folder for saving cache files.
     *
     * @todo clean up how $this->saveFolder is used in other methods.
     *
     * @param string $path where to store cached files.
     *
     * @return $this
     */
    public function setSaveFolder($path)
    {
        $this->saveFolder = $path;
        return $this;
    }



    /**
     * Use cache or not.
     *
     * @todo clean up how $this->noCache is used in other methods.
     *
     * @param string $use true or false to use cache.
     *
     * @return $this
     */
    public function useCache($use = true)
    {
        $this->useCache = $use;
        return $this;
    }



    /**
     * Allow or disallow remote image download.
     *
     * @param boolean $allow   true or false to enable and disable.
     * @param string  $pattern to use to detect if its a remote file.
     *
     * @return $this
     */
    public function setRemoteDownload($allow, $pattern = null)
    {
        $this->allowRemote = $allow;
        $this->remotePattern = $pattern ? $pattern : $this->remotePattern;

        $this->log("Set remote download to: "
            . ($this->allowRemote ? "true" : "false")
            . " using pattern "
            . $this->remotePattern);

        return $this;
    }



    /**
     * Check if the image resource is a remote file or not.
     *
     * @param string $src check if src is remote.
     *
     * @return boolean true if $src is a remote file, else false.
     */
    public function isRemoteSource($src)
    {
        $remote = preg_match($this->remotePattern, $src);
        $this->log("Detected remote image: " . ($remote ? "true" : "false"));
        return $remote;
    }



    /**
     * Check if file extension is valid as a file extension.
     *
     * @param string $extension of image file.
     *
     * @return $this
     */
    private function checkFileExtension($extension)
    {
        $valid = array('jpg', 'jpeg', 'png', 'gif');

        in_array(strtolower($extension), $valid)
            or $this->raiseError('Not a valid file extension.');

        return $this;
    }



    /**
     * Download a remote image and return path to its local copy.
     *
     * @param string $src remote path to image.
     *
     * @return string as path to downloaded remote source.
     */
    public function downloadRemoteSource($src)
    {
        $remote = new CRemoteImage();
        $cache  = $this->saveFolder . "/remote/";

        if (!is_dir($cache)) {
            mkdir($cache);
            $this->log("The remote cache does not exists, creating it.");
        }

        if (!is_writable($cache)) {
            $this->log("The remote cache is not writable.");
        }

        $remote->setCache($cache);
        $remote->useCache($this->useCache);
        $src = $remote->download($src);

        $this->log("Remote HTTP status: " . $remote->getStatus());
        $this->log("Remote item has local cached file: $src");
        $this->log("Remote details on cache:" . print_r($remote->getDetails(), true));

        return $src;
    }



    /**
     * Set src file.
     *
     * @param string $src of image.
     * @param string $dir as base directory where images are.
     *
     * @return $this
     */
    public function setSource($src, $dir = null)
    {
        if (!isset($src)) {
            return $this;
        }

        if ($this->allowRemote && $this->isRemoteSource($src)) {
            $src = $this->downloadRemoteSource($src);
            $dir = null;
        }

        if (!isset($dir)) {
            $dir = dirname($src);
            $src = basename($src);
        }

        $this->imageSrc       = ltrim($src, '/');
        $this->imageFolder    = rtrim($dir, '/');
        $this->pathToImage    = $this->imageFolder . '/' . $this->imageSrc;
        $this->fileExtension  = strtolower(pathinfo($this->pathToImage, PATHINFO_EXTENSION));
        //$this->extension      = $this->fileExtension;

        $this->checkFileExtension($this->fileExtension);

        return $this;
    }



    /**
     * Set target file.
     *
     * @param string $src of target image.
     * @param string $dir as base directory where images are stored.
     *
     * @return $this
     */
    public function setTarget($src = null, $dir = null)
    {
        if (!(isset($src) && isset($dir))) {
            return $this;
        }

        $this->saveFolder     = $dir;
        $this->cacheFileName  = $dir . '/' . $src;

        /* Allow readonly cache
        is_writable($this->saveFolder)
            or $this->raiseError('Target directory is not writable.');
        */

        // Sanitize filename
        $this->cacheFileName = preg_replace('/^a-zA-Z0-9\.-_/', '', $this->cacheFileName);
        $this->log("The cache file name is: " . $this->cacheFileName);

        return $this;
    }



    /**
     * Set options to use when processing image.
     *
     * @param array $args used when processing image.
     *
     * @return $this
     */
    public function setOptions($args)
    {
        $this->log("Set new options for processing image.");

        $defaults = array(
            // Options for calculate dimensions
            'newWidth'    => null,
            'newHeight'   => null,
            'aspectRatio' => null,
            'keepRatio'   => true,
            'cropToFit'   => false,
            'fillToFit'   => null,
            'crop'        => null, //array('width'=>null, 'height'=>null, 'start_x'=>0, 'start_y'=>0),
            'area'        => null, //'0,0,0,0',
            'upscale'     => self::UPSCALE_DEFAULT,

            // Options for caching or using original
            'useCache'    => true,
            'useOriginal' => true,

            // Pre-processing, before resizing is done
            'scale'        => null,
            'rotateBefore' => null,
            'autoRotate'  => false,

            // General options
            'bgColor'     => null,

            // Post-processing, after resizing is done
            'palette'     => null,
            'filters'     => null,
            'sharpen'     => null,
            'emboss'      => null,
            'blur'        => null,
            'convolve'       => null,
            'rotateAfter' => null,

            // Output format
            'outputFormat' => null,
            'dpr'          => 1,

            // Options for saving
            //'quality'     => null,
            //'compress'    => null,
            //'saveAs'      => null,
        );

        // Convert crop settings from string to array
        if (isset($args['crop']) && !is_array($args['crop'])) {
            $pices = explode(',', $args['crop']);
            $args['crop'] = array(
                'width'   => $pices[0],
                'height'  => $pices[1],
                'start_x' => $pices[2],
                'start_y' => $pices[3],
            );
        }

        // Convert area settings from string to array
        if (isset($args['area']) && !is_array($args['area'])) {
                $pices = explode(',', $args['area']);
                $args['area'] = array(
                    'top'    => $pices[0],
                    'right'  => $pices[1],
                    'bottom' => $pices[2],
                    'left'   => $pices[3],
                );
        }

        // Convert filter settings from array of string to array of array
        if (isset($args['filters']) && is_array($args['filters'])) {
            foreach ($args['filters'] as $key => $filterStr) {
                $parts = explode(',', $filterStr);
                $filter = $this->mapFilter($parts[0]);
                $filter['str'] = $filterStr;
                for ($i=1; $i<=$filter['argc']; $i++) {
                    if (isset($parts[$i])) {
                        $filter["arg{$i}"] = $parts[$i];
                    } else {
                        throw new Exception(
                            'Missing arg to filter, review how many arguments are needed at
                            http://php.net/manual/en/function.imagefilter.php'
                        );
                    }
                }
                $args['filters'][$key] = $filter;
            }
        }

        // Merge default arguments with incoming and set properties.
        //$args = array_merge_recursive($defaults, $args);
        $args = array_merge($defaults, $args);
        foreach ($defaults as $key => $val) {
            $this->{$key} = $args[$key];
        }

        if ($this->bgColor) {
            $this->setDefaultBackgroundColor($this->bgColor);
        }

        // Save original values to enable re-calculating
        $this->newWidthOrig  = $this->newWidth;
        $this->newHeightOrig = $this->newHeight;
        $this->cropOrig      = $this->crop;

        return $this;
    }



    /**
     * Map filter name to PHP filter and id.
     *
     * @param string $name the name of the filter.
     *
     * @return array with filter settings
     * @throws Exception
     */
    private function mapFilter($name)
    {
        $map = array(
            'negate'          => array('id'=>0,  'argc'=>0, 'type'=>IMG_FILTER_NEGATE),
            'grayscale'       => array('id'=>1,  'argc'=>0, 'type'=>IMG_FILTER_GRAYSCALE),
            'brightness'      => array('id'=>2,  'argc'=>1, 'type'=>IMG_FILTER_BRIGHTNESS),
            'contrast'        => array('id'=>3,  'argc'=>1, 'type'=>IMG_FILTER_CONTRAST),
            'colorize'        => array('id'=>4,  'argc'=>4, 'type'=>IMG_FILTER_COLORIZE),
            'edgedetect'      => array('id'=>5,  'argc'=>0, 'type'=>IMG_FILTER_EDGEDETECT),
            'emboss'          => array('id'=>6,  'argc'=>0, 'type'=>IMG_FILTER_EMBOSS),
            'gaussian_blur'   => array('id'=>7,  'argc'=>0, 'type'=>IMG_FILTER_GAUSSIAN_BLUR),
            'selective_blur'  => array('id'=>8,  'argc'=>0, 'type'=>IMG_FILTER_SELECTIVE_BLUR),
            'mean_removal'    => array('id'=>9,  'argc'=>0, 'type'=>IMG_FILTER_MEAN_REMOVAL),
            'smooth'          => array('id'=>10, 'argc'=>1, 'type'=>IMG_FILTER_SMOOTH),
            'pixelate'        => array('id'=>11, 'argc'=>2, 'type'=>IMG_FILTER_PIXELATE),
        );

        if (isset($map[$name])) {
            return $map[$name];
        } else {
            throw new Exception('No such filter.');
        }
    }



    /**
     * Load image details from original image file.
     *
     * @param string $file the file to load or null to use $this->pathToImage.
     *
     * @return $this
     * @throws Exception
     */
    public function loadImageDetails($file = null)
    {
        $file = $file ? $file : $this->pathToImage;

        is_readable($file)
            or $this->raiseError('Image file does not exist.');

        // Get details on image
        $info = list($this->width, $this->height, $this->type, $this->attr) = getimagesize($file);
        !empty($info) or $this->raiseError("The file doesn't seem to be an image.");

        if ($this->verbose) {
            $this->log("Image file: {$file}");
            $this->log("Image width x height (type): {$this->width} x {$this->height} ({$this->type}).");
            $this->log("Image filesize: " . filesize($file) . " bytes.");
        }

        return $this;
    }



    /**
     * Init new width and height and do some sanity checks on constraints, before any
     * processing can be done.
     *
     * @return $this
     * @throws Exception
     */
    public function initDimensions()
    {
        $this->log("Init dimension (before) newWidth x newHeight is {$this->newWidth} x {$this->newHeight}.");

        // width as %
        if ($this->newWidth[strlen($this->newWidth)-1] == '%') {
            $this->newWidth = $this->width * substr($this->newWidth, 0, -1) / 100;
            $this->log("Setting new width based on % to {$this->newWidth}");
        }

        // height as %
        if ($this->newHeight[strlen($this->newHeight)-1] == '%') {
            $this->newHeight = $this->height * substr($this->newHeight, 0, -1) / 100;
            $this->log("Setting new height based on % to {$this->newHeight}");
        }

        is_null($this->aspectRatio) or is_numeric($this->aspectRatio) or $this->raiseError('Aspect ratio out of range');

        // width & height from aspect ratio
        if ($this->aspectRatio && is_null($this->newWidth) && is_null($this->newHeight)) {
            if ($this->aspectRatio >= 1) {
                $this->newWidth   = $this->width;
                $this->newHeight  = $this->width / $this->aspectRatio;
                $this->log("Setting new width & height based on width & aspect ratio (>=1) to (w x h) {$this->newWidth} x {$this->newHeight}");

            } else {
                $this->newHeight  = $this->height;
                $this->newWidth   = $this->height * $this->aspectRatio;
                $this->log("Setting new width & height based on width & aspect ratio (<1) to (w x h) {$this->newWidth} x {$this->newHeight}");
            }

        } elseif ($this->aspectRatio && is_null($this->newWidth)) {
            $this->newWidth   = $this->newHeight * $this->aspectRatio;
            $this->log("Setting new width based on aspect ratio to {$this->newWidth}");

        } elseif ($this->aspectRatio && is_null($this->newHeight)) {
            $this->newHeight  = $this->newWidth / $this->aspectRatio;
            $this->log("Setting new height based on aspect ratio to {$this->newHeight}");
        }

        // Change width & height based on dpr
        if ($this->dpr != 1) {
            if (!is_null($this->newWidth)) {
                $this->newWidth  = round($this->newWidth * $this->dpr);
                $this->log("Setting new width based on dpr={$this->dpr} - w={$this->newWidth}");
            }
            if (!is_null($this->newHeight)) {
                $this->newHeight = round($this->newHeight * $this->dpr);
                $this->log("Setting new height based on dpr={$this->dpr} - h={$this->newHeight}");
            }
        }

        // Check values to be within domain
        is_null($this->newWidth)
            or is_numeric($this->newWidth)
            or $this->raiseError('Width not numeric');

        is_null($this->newHeight)
            or is_numeric($this->newHeight)
            or $this->raiseError('Height not numeric');

        $this->log("Init dimension (after) newWidth x newHeight is {$this->newWidth} x {$this->newHeight}.");

        return $this;
    }



    /**
     * Calculate new width and height of image, based on settings.
     *
     * @return $this
     */
    public function calculateNewWidthAndHeight()
    {
        // Crop, use cropped width and height as base for calulations
        $this->log("Calculate new width and height.");
        $this->log("Original width x height is {$this->width} x {$this->height}.");
        $this->log("Target dimension (before calculating) newWidth x newHeight is {$this->newWidth} x {$this->newHeight}.");

        // Check if there is an area to crop off
        if (isset($this->area)) {
            $this->offset['top']    = round($this->area['top'] / 100 * $this->height);
            $this->offset['right']  = round($this->area['right'] / 100 * $this->width);
            $this->offset['bottom'] = round($this->area['bottom'] / 100 * $this->height);
            $this->offset['left']   = round($this->area['left'] / 100 * $this->width);
            $this->offset['width']  = $this->width - $this->offset['left'] - $this->offset['right'];
            $this->offset['height'] = $this->height - $this->offset['top'] - $this->offset['bottom'];
            $this->width  = $this->offset['width'];
            $this->height = $this->offset['height'];
            $this->log("The offset for the area to use is top {$this->area['top']}%, right {$this->area['right']}%, bottom {$this->area['bottom']}%, left {$this->area['left']}%.");
            $this->log("The offset for the area to use is top {$this->offset['top']}px, right {$this->offset['right']}px, bottom {$this->offset['bottom']}px, left {$this->offset['left']}px, width {$this->offset['width']}px, height {$this->offset['height']}px.");
        }

        $width  = $this->width;
        $height = $this->height;

        // Check if crop is set
        if ($this->crop) {
            $width  = $this->crop['width']  = $this->crop['width'] <= 0 ? $this->width + $this->crop['width'] : $this->crop['width'];
            $height = $this->crop['height'] = $this->crop['height'] <= 0 ? $this->height + $this->crop['height'] : $this->crop['height'];

            if ($this->crop['start_x'] == 'left') {
                $this->crop['start_x'] = 0;
            } elseif ($this->crop['start_x'] == 'right') {
                $this->crop['start_x'] = $this->width - $width;
            } elseif ($this->crop['start_x'] == 'center') {
                $this->crop['start_x'] = round($this->width / 2) - round($width / 2);
            }

            if ($this->crop['start_y'] == 'top') {
                $this->crop['start_y'] = 0;
            } elseif ($this->crop['start_y'] == 'bottom') {
                $this->crop['start_y'] = $this->height - $height;
            } elseif ($this->crop['start_y'] == 'center') {
                $this->crop['start_y'] = round($this->height / 2) - round($height / 2);
            }

            $this->log("Crop area is width {$width}px, height {$height}px, start_x {$this->crop['start_x']}px, start_y {$this->crop['start_y']}px.");
        }

        // Calculate new width and height if keeping aspect-ratio.
        if ($this->keepRatio) {

            $this->log("Keep aspect ratio.");

            // Crop-to-fit and both new width and height are set.
            if (($this->cropToFit || $this->fillToFit) && isset($this->newWidth) && isset($this->newHeight)) {

                // Use newWidth and newHeigh as width/height, image should fit in box.
                $this->log("Use newWidth and newHeigh as width/height, image should fit in box.");

            } elseif (isset($this->newWidth) && isset($this->newHeight)) {

                // Both new width and height are set.
                // Use newWidth and newHeigh as max width/height, image should not be larger.
                $ratioWidth  = $width  / $this->newWidth;
                $ratioHeight = $height / $this->newHeight;
                $ratio = ($ratioWidth > $ratioHeight) ? $ratioWidth : $ratioHeight;
                $this->newWidth  = round($width  / $ratio);
                $this->newHeight = round($height / $ratio);
                $this->log("New width and height was set.");

            } elseif (isset($this->newWidth)) {

                // Use new width as max-width
                $factor = (float)$this->newWidth / (float)$width;
                $this->newHeight = round($factor * $height);
                $this->log("New width was set.");

            } elseif (isset($this->newHeight)) {

                // Use new height as max-hight
                $factor = (float)$this->newHeight / (float)$height;
                $this->newWidth = round($factor * $width);
                $this->log("New height was set.");

            }

            // Get image dimensions for pre-resize image.
            if ($this->cropToFit || $this->fillToFit) {

                // Get relations of original & target image
                $ratioWidth  = $width  / $this->newWidth;
                $ratioHeight = $height / $this->newHeight;

                if ($this->cropToFit) {

                    // Use newWidth and newHeigh as defined width/height,
                    // image should fit the area.
                    $this->log("Crop to fit.");
                    $ratio = ($ratioWidth < $ratioHeight) ? $ratioWidth : $ratioHeight;
                    $this->cropWidth  = round($width  / $ratio);
                    $this->cropHeight = round($height / $ratio);
                    $this->log("Crop width, height, ratio: $this->cropWidth x $this->cropHeight ($ratio).");

                } else if ($this->fillToFit) {

                    // Use newWidth and newHeigh as defined width/height,
                    // image should fit the area.
                    $this->log("Fill to fit.");
                    $ratio = ($ratioWidth < $ratioHeight) ? $ratioHeight : $ratioWidth;
                    $this->fillWidth  = round($width  / $ratio);
                    $this->fillHeight = round($height / $ratio);
                    $this->log("Fill width, height, ratio: $this->fillWidth x $this->fillHeight ($ratio).");
                }
            }
        }

        // Crop, ensure to set new width and height
        if ($this->crop) {
            $this->log("Crop.");
            $this->newWidth = round(isset($this->newWidth) ? $this->newWidth : $this->crop['width']);
            $this->newHeight = round(isset($this->newHeight) ? $this->newHeight : $this->crop['height']);
        }

        // Fill to fit, ensure to set new width and height
        /*if ($this->fillToFit) {
            $this->log("FillToFit.");
            $this->newWidth = round(isset($this->newWidth) ? $this->newWidth : $this->crop['width']);
            $this->newHeight = round(isset($this->newHeight) ? $this->newHeight : $this->crop['height']);
        }*/

        // No new height or width is set, use existing measures.
        $this->newWidth  = round(isset($this->newWidth) ? $this->newWidth : $this->width);
        $this->newHeight = round(isset($this->newHeight) ? $this->newHeight : $this->height);
        $this->log("Calculated new width x height as {$this->newWidth} x {$this->newHeight}.");

        return $this;
    }



    /**
     * Re-calculate image dimensions when original image dimension has changed.
     *
     * @return $this
     */
    public function reCalculateDimensions()
    {
        $this->log("Re-calculate image dimensions, newWidth x newHeigh was: " . $this->newWidth . " x " . $this->newHeight);

        $this->newWidth  = $this->newWidthOrig;
        $this->newHeight = $this->newHeightOrig;
        $this->crop      = $this->cropOrig;

        $this->initDimensions()
             ->calculateNewWidthAndHeight();

        return $this;
    }



    /**
     * Set extension for filename to save as.
     *
     * @param string $saveas extension to save image as
     *
     * @return $this
     */
    public function setSaveAsExtension($saveAs = null)
    {
        if (isset($saveAs)) {
            $saveAs = strtolower($saveAs);
            $this->checkFileExtension($saveAs);
            $this->saveAs = $saveAs;
            $this->extension = $saveAs;
        }

        $this->log("Prepare to save image using as: " . $this->extension);

        return $this;
    }



    /**
     * Set JPEG quality to use when saving image
     *
     * @param int $quality as the quality to set.
     *
     * @return $this
     */
    public function setJpegQuality($quality = null)
    {
        if ($quality) {
            $this->useQuality = true;
        }

        $this->quality = isset($quality)
            ? $quality
            : self::JPEG_QUALITY_DEFAULT;

        (is_numeric($this->quality) and $this->quality > 0 and $this->quality <= 100)
            or $this->raiseError('Quality not in range.');

        $this->log("Setting JPEG quality to {$this->quality}.");

        return $this;
    }



    /**
     * Set PNG compressen algorithm to use when saving image
     *
     * @param int $compress as the algorithm to use.
     *
     * @return $this
     */
    public function setPngCompression($compress = null)
    {
        if ($compress) {
            $this->useCompress = true;
        }

        $this->compress = isset($compress)
            ? $compress
            : self::PNG_COMPRESSION_DEFAULT;

        (is_numeric($this->compress) and $this->compress >= -1 and $this->compress <= 9)
            or $this->raiseError('Quality not in range.');

        $this->log("Setting PNG compression level to {$this->compress}.");

        return $this;
    }



    /**
     * Use original image if possible, check options which affects image processing.
     *
     * @param boolean $useOrig default is to use original if possible, else set to false.
     *
     * @return $this
     */
    public function useOriginalIfPossible($useOrig = true)
    {
        if ($useOrig
            && ($this->newWidth == $this->width)
            && ($this->newHeight == $this->height)
            && !$this->area
            && !$this->crop
            && !$this->cropToFit
            && !$this->fillToFit
            && !$this->filters
            && !$this->sharpen
            && !$this->emboss
            && !$this->blur
            && !$this->convolve
            && !$this->palette
            && !$this->useQuality
            && !$this->useCompress
            && !$this->saveAs
            && !$this->rotateBefore
            && !$this->rotateAfter
            && !$this->autoRotate
            && !$this->bgColor
            && ($this->upscale === self::UPSCALE_DEFAULT)
        ) {
            $this->log("Using original image.");
            $this->output($this->pathToImage);
        }

        return $this;
    }



    /**
     * Generate filename to save file in cache.
     *
     * @param string $base as basepath for storing file.
     *
     * @return $this
     */
    public function generateFilename($base)
    {
        $parts        = pathinfo($this->pathToImage);
        $cropToFit    = $this->cropToFit    ? '_cf'                      : null;
        $fillToFit    = $this->fillToFit    ? '_ff'                      : null;
        $crop_x       = $this->crop_x       ? "_x{$this->crop_x}"        : null;
        $crop_y       = $this->crop_y       ? "_y{$this->crop_y}"        : null;
        $scale        = $this->scale        ? "_s{$this->scale}"         : null;
        $bgColor      = $this->bgColor      ? "_bgc{$this->bgColor}"     : null;
        $quality      = $this->quality      ? "_q{$this->quality}"       : null;
        $compress     = $this->compress     ? "_co{$this->compress}"     : null;
        $rotateBefore = $this->rotateBefore ? "_rb{$this->rotateBefore}" : null;
        $rotateAfter  = $this->rotateAfter  ? "_ra{$this->rotateAfter}"  : null;

        $width  = $this->newWidth;
        $height = $this->newHeight;

        $offset = isset($this->offset)
            ? '_o' . $this->offset['top'] . '-' . $this->offset['right'] . '-' . $this->offset['bottom'] . '-' . $this->offset['left']
            : null;

        $crop = $this->crop
            ? '_c' . $this->crop['width'] . '-' . $this->crop['height'] . '-' . $this->crop['start_x'] . '-' . $this->crop['start_y']
            : null;

        $filters = null;
        if (isset($this->filters)) {
            foreach ($this->filters as $filter) {
                if (is_array($filter)) {
                    $filters .= "_f{$filter['id']}";
                    for ($i=1; $i<=$filter['argc']; $i++) {
                        $filters .= ":".$filter["arg{$i}"];
                    }
                }
            }
        }

        $sharpen = $this->sharpen ? 's' : null;
        $emboss  = $this->emboss  ? 'e' : null;
        $blur    = $this->blur    ? 'b' : null;
        $palette = $this->palette ? 'p' : null;

        $autoRotate = $this->autoRotate ? 'ar' : null;

        $this->extension = isset($this->extension)
            ? $this->extension
            : $parts['extension'];

        $optimize = null;
        if ($this->extension == 'jpeg' || $this->extension == 'jpg') {
            $optimize = $this->jpegOptimize ? 'o' : null;
        } elseif ($this->extension == 'png') {
            $optimize .= $this->pngFilter  ? 'f' : null;
            $optimize .= $this->pngDeflate ? 'd' : null;
        }

        $convolve = null;
        if ($this->convolve) {
            $convolve = '_conv' . preg_replace('/[^a-zA-Z0-9]/', '', $this->convolve);
        }

        $upscale = null;
        if ($this->upscale !== self::UPSCALE_DEFAULT) {
            $upscale = '_nu';
        }

        $subdir = str_replace('/', '-', dirname($this->imageSrc));
        $subdir = ($subdir == '.') ? '_.' : $subdir;
        $file = $subdir . '_' . $parts['filename'] . '_' . $width . '_'
            . $height . $offset . $crop . $cropToFit . $fillToFit
            . $crop_x . $crop_y . $upscale
            . $quality . $filters . $sharpen . $emboss . $blur . $palette . $optimize
            . $scale . $rotateBefore . $rotateAfter . $autoRotate . $bgColor . $convolve
            . '.' . $this->extension;

        return $this->setTarget($file, $base);
    }



    /**
     * Use cached version of image, if possible.
     *
     * @param boolean $useCache is default true, set to false to avoid using cached object.
     *
     * @return $this
     */
    public function useCacheIfPossible($useCache = true)
    {
        if ($useCache && is_readable($this->cacheFileName)) {
            $fileTime   = filemtime($this->pathToImage);
            $cacheTime  = filemtime($this->cacheFileName);

            if ($fileTime <= $cacheTime) {
                if ($this->useCache) {
                    if ($this->verbose) {
                        $this->log("Use cached file.");
                        $this->log("Cached image filesize: " . filesize($this->cacheFileName) . " bytes.");
                    }
                    $this->output($this->cacheFileName, $this->outputFormat);
                } else {
                    $this->log("Cache is valid but ignoring it by intention.");
                }
            } else {
                $this->log("Original file is modified, ignoring cache.");
            }
        } else {
            $this->log("Cachefile does not exists or ignoring it.");
        }

        return $this;
    }



    /**
     * Error message when failing to load somehow corrupt image.
     *
     * @return void
     *
     */
    public function failedToLoad()
    {
        header("HTTP/1.0 404 Not Found");
        echo("CImage.php says 404: Fatal error when opening image.<br>");

        switch ($this->fileExtension) {
            case 'jpg':
            case 'jpeg':
                $this->image = imagecreatefromjpeg($this->pathToImage);
                break;

            case 'gif':
                $this->image = imagecreatefromgif($this->pathToImage);
                break;

            case 'png':
                $this->image = imagecreatefrompng($this->pathToImage);
                break;
        }

        exit();
    }



    /**
     * Load image from disk.
     *
     * @param string $src of image.
     * @param string $dir as base directory where images are.
     *
     * @return $this
     *
     */
    public function load($src = null, $dir = null)
    {
        if (isset($src)) {
            $this->setSource($src, $dir);
        }

        $this->log("Opening file as {$this->fileExtension}.");

        switch ($this->fileExtension) {
            case 'jpg':
            case 'jpeg':
                $this->image = @imagecreatefromjpeg($this->pathToImage);
                $this->image or $this->failedToLoad();
                break;

            case 'gif':
                $this->image = @imagecreatefromgif($this->pathToImage);
                $this->image or $this->failedToLoad();
                break;

            case 'png':
                $this->image = @imagecreatefrompng($this->pathToImage);
                $this->image or $this->failedToLoad();

                $type = $this->getPngType();
                $hasFewColors = imagecolorstotal($this->image);

                if ($type == self::PNG_RGB_PALETTE || ($hasFewColors > 0 && $hasFewColors <= 256)) {
                    if ($this->verbose) {
                        $this->log("Handle this image as a palette image.");
                    }
                    $this->palette = true;
                }
                break;

            default:
                $this->image = false;
                throw new Exception('No support for this file extension.');
        }

        if ($this->verbose) {
            $this->log("imageistruecolor() : " . (imageistruecolor($this->image) ? 'true' : 'false'));
            $this->log("imagecolorstotal() : " . imagecolorstotal($this->image));
            $this->log("Number of colors in image = " . $this->colorsTotal($this->image));
        }

        return $this;
    }



    /**
     * Get the type of PNG image.
     *
     * @return int as the type of the png-image
     *
     */
    private function getPngType()
    {
        $pngType = ord(file_get_contents($this->pathToImage, false, null, 25, 1));

        switch ($pngType) {

            case self::PNG_GREYSCALE:
                $this->log("PNG is type 0, Greyscale.");
                break;

            case self::PNG_RGB:
                $this->log("PNG is type 2, RGB");
                break;

            case self::PNG_RGB_PALETTE:
                $this->log("PNG is type 3, RGB with palette");
                break;

            case self::PNG_GREYSCALE_ALPHA:
                $this->Log("PNG is type 4, Greyscale with alpha channel");
                break;

            case self::PNG_RGB_ALPHA:
                $this->Log("PNG is type 6, RGB with alpha channel (PNG 32-bit)");
                break;

            default:
                $this->Log("PNG is UNKNOWN type, is it really a PNG image?");
        }

        return $pngType;
    }



    /**
     * Calculate number of colors in an image.
     *
     * @param resource $im the image.
     *
     * @return int
     */
    private function colorsTotal($im)
    {
        if (imageistruecolor($im)) {
            $this->log("Colors as true color.");
            $h = imagesy($im);
            $w = imagesx($im);
            $c = array();
            for ($x=0; $x < $w; $x++) {
                for ($y=0; $y < $h; $y++) {
                    @$c['c'.imagecolorat($im, $x, $y)]++;
                }
            }
            return count($c);
        } else {
            $this->log("Colors as palette.");
            return imagecolorstotal($im);
        }
    }



    /**
     * Preprocess image before rezising it.
     *
     * @return $this
     */
    public function preResize()
    {
        $this->log("Pre-process before resizing");

        // Rotate image
        if ($this->rotateBefore) {
            $this->log("Rotating image.");
            $this->rotate($this->rotateBefore, $this->bgColor)
                 ->reCalculateDimensions();
        }

        // Auto-rotate image
        if ($this->autoRotate) {
            $this->log("Auto rotating image.");
            $this->rotateExif()
                 ->reCalculateDimensions();
        }

        // Scale the original image before starting
        if (isset($this->scale)) {
            $this->log("Scale by {$this->scale}%");
            $newWidth  = $this->width * $this->scale / 100;
            $newHeight = $this->height * $this->scale / 100;
            $img = $this->CreateImageKeepTransparency($newWidth, $newHeight);
            imagecopyresampled($img, $this->image, 0, 0, 0, 0, $newWidth, $newHeight, $this->width, $this->height);
            $this->image = $img;
            $this->width = $newWidth;
            $this->height = $newHeight;
        }

        return $this;
    }



    /**
     * Resize and or crop the image.
     *
     * @return $this
     */
    public function resize()
    {

        $this->log("Starting to Resize()");
        $this->log("Upscale = '$this->upscale'");

        // Only use a specified area of the image, $this->offset is defining the area to use
        if (isset($this->offset)) {

            $this->log("Offset for area to use, cropping it width={$this->offset['width']}, height={$this->offset['height']}, start_x={$this->offset['left']}, start_y={$this->offset['top']}");
            $img = $this->CreateImageKeepTransparency($this->offset['width'], $this->offset['height']);
            imagecopy($img, $this->image, 0, 0, $this->offset['left'], $this->offset['top'], $this->offset['width'], $this->offset['height']);
            $this->image = $img;
            $this->width = $this->offset['width'];
            $this->height = $this->offset['height'];
        }

        if ($this->crop) {

            // Do as crop, take only part of image
            $this->log("Cropping area width={$this->crop['width']}, height={$this->crop['height']}, start_x={$this->crop['start_x']}, start_y={$this->crop['start_y']}");
            $img = $this->CreateImageKeepTransparency($this->crop['width'], $this->crop['height']);
            imagecopy($img, $this->image, 0, 0, $this->crop['start_x'], $this->crop['start_y'], $this->crop['width'], $this->crop['height']);
            $this->image = $img;
            $this->width = $this->crop['width'];
            $this->height = $this->crop['height'];
        }

        if (!$this->upscale) {
            // Consider rewriting the no-upscale code to fit within this if-statement,
            // likely to be more readable code.
            // The code is more or leass equal in below crop-to-fit, fill-to-fit and stretch
        }

        if ($this->cropToFit) {

            // Resize by crop to fit
            $this->log("Resizing using strategy - Crop to fit");

            if (!$this->upscale && ($this->width < $this->newWidth || $this->height < $this->newHeight)) {
                $this->log("Resizing - smaller image, do not upscale.");

                $cropX = round(($this->cropWidth/2) - ($this->newWidth/2));
                $cropY = round(($this->cropHeight/2) - ($this->newHeight/2));

                $posX = 0;
                $posY = 0;

                if ($this->newWidth > $this->width) {
                    $posX = round(($this->newWidth - $this->width) / 2);
                }

                if ($this->newHeight > $this->height) {
                    $posY = round(($this->newHeight - $this->height) / 2);
                }

                $imageResized = $this->CreateImageKeepTransparency($this->newWidth, $this->newHeight);
                imagecopy($imageResized, $this->image, $posX, $posY, $cropX, $cropY, $this->newWidth, $this->newHeight);
            } else {
                $cropX = round(($this->cropWidth/2) - ($this->newWidth/2));
                $cropY = round(($this->cropHeight/2) - ($this->newHeight/2));
                $imgPreCrop   = $this->CreateImageKeepTransparency($this->cropWidth, $this->cropHeight);
                $imageResized = $this->CreateImageKeepTransparency($this->newWidth, $this->newHeight);
                imagecopyresampled($imgPreCrop, $this->image, 0, 0, 0, 0, $this->cropWidth, $this->cropHeight, $this->width, $this->height);
                imagecopy($imageResized, $imgPreCrop, 0, 0, $cropX, $cropY, $this->newWidth, $this->newHeight);
            }

            $this->image = $imageResized;
            $this->width = $this->newWidth;
            $this->height = $this->newHeight;

        } else if ($this->fillToFit) {

            // Resize by fill to fit
            $this->log("Resizing using strategy - Fill to fit");

            $posX = 0;
            $posY = 0;

            $ratioOrig = $this->width / $this->height;
            $ratioNew  = $this->newWidth / $this->newHeight;

            // Check ratio for landscape or portrait
            if ($ratioOrig < $ratioNew) {
                $posX = round(($this->newWidth - $this->fillWidth) / 2);
            } else {
                $posY = round(($this->newHeight - $this->fillHeight) / 2);
            }

            if (!$this->upscale
                && ($this->width < $this->newWidth || $this->height < $this->newHeight)
            ) {

                $this->log("Resizing - smaller image, do not upscale.");
                $posX = round(($this->fillWidth - $this->width) / 2);
                $posY = round(($this->fillHeight - $this->height) / 2);
                $imageResized = $this->CreateImageKeepTransparency($this->newWidth, $this->newHeight);
                imagecopy($imageResized, $this->image, $posX, $posY, 0, 0, $this->fillWidth, $this->fillHeight);

            } else {
                $imgPreFill   = $this->CreateImageKeepTransparency($this->fillWidth, $this->fillHeight);
                $imageResized = $this->CreateImageKeepTransparency($this->newWidth, $this->newHeight);
                imagecopyresampled($imgPreFill, $this->image, 0, 0, 0, 0, $this->fillWidth, $this->fillHeight, $this->width, $this->height);
                imagecopy($imageResized, $imgPreFill, $posX, $posY, 0, 0, $this->fillWidth, $this->fillHeight);
            }

            $this->image = $imageResized;
            $this->width = $this->newWidth;
            $this->height = $this->newHeight;

        } else if (!($this->newWidth == $this->width && $this->newHeight == $this->height)) {

            // Resize it
            $this->log("Resizing, new height and/or width");

            if (!$this->upscale
                && ($this->width < $this->newWidth || $this->height < $this->newHeight)
            ) {
                $this->log("Resizing - smaller image, do not upscale.");

                if (!$this->keepRatio) {
                    $this->log("Resizing - stretch to fit selected.");

                    $posX = 0;
                    $posY = 0;
                    $cropX = 0;
                    $cropY = 0;

                    if ($this->newWidth > $this->width && $this->newHeight > $this->height) {
                        $posX = round(($this->newWidth - $this->width) / 2);
                        $posY = round(($this->newHeight - $this->height) / 2);
                    } else if ($this->newWidth > $this->width) {
                        $posX = round(($this->newWidth - $this->width) / 2);
                        $cropY = round(($this->height - $this->newHeight) / 2);
                    } else if ($this->newHeight > $this->height) {
                        $posY = round(($this->newHeight - $this->height) / 2);
                        $cropX = round(($this->width - $this->newWidth) / 2);
                    }

                    //$this->log("posX=$posX, posY=$posY, cropX=$cropX, cropY=$cropY.");
                    $imageResized = $this->CreateImageKeepTransparency($this->newWidth, $this->newHeight);
                    imagecopy($imageResized, $this->image, $posX, $posY, $cropX, $cropY, $this->newWidth, $this->newHeight);
                    $this->image = $imageResized;
                    $this->width = $this->newWidth;
                    $this->height = $this->newHeight;
                }
            } else {
                $imageResized = $this->CreateImageKeepTransparency($this->newWidth, $this->newHeight);
                imagecopyresampled($imageResized, $this->image, 0, 0, 0, 0, $this->newWidth, $this->newHeight, $this->width, $this->height);
                $this->image = $imageResized;
                $this->width = $this->newWidth;
                $this->height = $this->newHeight;
            }
        }

        return $this;
    }



    /**
     * Postprocess image after rezising image.
     *
     * @return $this
     */
    public function postResize()
    {
        $this->log("Post-process after resizing");

        // Rotate image
        if ($this->rotateAfter) {
            $this->log("Rotating image.");
            $this->rotate($this->rotateAfter, $this->bgColor);
        }

        // Apply filters
        if (isset($this->filters) && is_array($this->filters)) {

            foreach ($this->filters as $filter) {
                $this->log("Applying filter {$filter['type']}.");

                switch ($filter['argc']) {

                    case 0:
                        imagefilter($this->image, $filter['type']);
                        break;

                    case 1:
                        imagefilter($this->image, $filter['type'], $filter['arg1']);
                        break;

                    case 2:
                        imagefilter($this->image, $filter['type'], $filter['arg1'], $filter['arg2']);
                        break;

                    case 3:
                        imagefilter($this->image, $filter['type'], $filter['arg1'], $filter['arg2'], $filter['arg3']);
                        break;

                    case 4:
                        imagefilter($this->image, $filter['type'], $filter['arg1'], $filter['arg2'], $filter['arg3'], $filter['arg4']);
                        break;
                }
            }
        }

        // Convert to palette image
        if ($this->palette) {
            $this->log("Converting to palette image.");
            $this->trueColorToPalette();
        }

        // Blur the image
        if ($this->blur) {
            $this->log("Blur.");
            $this->blurImage();
        }

        // Emboss the image
        if ($this->emboss) {
            $this->log("Emboss.");
            $this->embossImage();
        }

        // Sharpen the image
        if ($this->sharpen) {
            $this->log("Sharpen.");
            $this->sharpenImage();
        }

        // Custom convolution
        if ($this->convolve) {
            //$this->log("Convolve: " . $this->convolve);
            $this->imageConvolution();
        }

        return $this;
    }



    /**
     * Rotate image using angle.
     *
     * @param float $angle        to rotate image.
     * @param int   $anglebgColor to fill image with if needed.
     *
     * @return $this
     */
    public function rotate($angle, $bgColor)
    {
        $this->log("Rotate image " . $angle . " degrees with filler color.");

        $color = $this->getBackgroundColor();
        $this->image = imagerotate($this->image, $angle, $color);

        $this->width  = imagesx($this->image);
        $this->height = imagesy($this->image);

        $this->log("New image dimension width x height: " . $this->width . " x " . $this->height);

        return $this;
    }



    /**
     * Rotate image using information in EXIF.
     *
     * @return $this
     */
    public function rotateExif()
    {
        if (!in_array($this->fileExtension, array('jpg', 'jpeg'))) {
            $this->log("Autorotate ignored, EXIF not supported by this filetype.");
            return $this;
        }

        $exif = exif_read_data($this->pathToImage);

        if (!empty($exif['Orientation'])) {
            switch ($exif['Orientation']) {
                case 3:
                    $this->log("Autorotate 180.");
                    $this->rotate(180, $this->bgColor);
                    break;

                case 6:
                    $this->log("Autorotate -90.");
                    $this->rotate(-90, $this->bgColor);
                    break;

                case 8:
                    $this->log("Autorotate 90.");
                    $this->rotate(90, $this->bgColor);
                    break;

                default:
                    $this->log("Autorotate ignored, unknown value as orientation.");
            }
        } else {
            $this->log("Autorotate ignored, no orientation in EXIF.");
        }

        return $this;
    }



    /**
     * Convert true color image to palette image, keeping alpha.
     * http://stackoverflow.com/questions/5752514/how-to-convert-png-to-8-bit-png-using-php-gd-library
     *
     * @return void
     */
    public function trueColorToPalette()
    {
        $img = imagecreatetruecolor($this->width, $this->height);
        $bga = imagecolorallocatealpha($img, 0, 0, 0, 127);
        imagecolortransparent($img, $bga);
        imagefill($img, 0, 0, $bga);
        imagecopy($img, $this->image, 0, 0, 0, 0, $this->width, $this->height);
        imagetruecolortopalette($img, false, 255);
        imagesavealpha($img, true);

        if (imageistruecolor($this->image)) {
            $this->log("Matching colors with true color image.");
            imagecolormatch($this->image, $img);
        }

        $this->image = $img;
    }



    /**
     * Sharpen image using image convolution.
     *
     * @return $this
     */
    public function sharpenImage()
    {
        $this->imageConvolution('sharpen');
        return $this;
    }



    /**
     * Emboss image using image convolution.
     *
     * @return $this
     */
    public function embossImage()
    {
        $this->imageConvolution('emboss');
        return $this;
    }



    /**
     * Blur image using image convolution.
     *
     * @return $this
     */
    public function blurImage()
    {
        $this->imageConvolution('blur');
        return $this;
    }



    /**
     * Create convolve expression and return arguments for image convolution.
     *
     * @param string $expression constant string which evaluates to a list of
     *                           11 numbers separated by komma or such a list.
     *
     * @return array as $matrix (3x3), $divisor and $offset
     */
    public function createConvolveArguments($expression)
    {
        // Check of matching constant
        if (isset($this->convolves[$expression])) {
            $expression = $this->convolves[$expression];
        }

        $part = explode(',', $expression);
        $this->log("Creating convolution expressen: $expression");

        // Expect list of 11 numbers, split by , and build up arguments
        if (count($part) != 11) {
            throw new Exception(
                "Missmatch in argument convolve. Expected comma-separated string with
                11 float values. Got $expression."
            );
        }

        array_walk($part, function ($item, $key) {
            if (!is_numeric($item)) {
                throw new Exception("Argument to convolve expression should be float but is not.");
            }
        });

        return array(
            array(
                array($part[0], $part[1], $part[2]),
                array($part[3], $part[4], $part[5]),
                array($part[6], $part[7], $part[8]),
            ),
            $part[9],
            $part[10],
        );
    }



    /**
     * Add custom expressions (or overwrite existing) for image convolution.
     *
     * @param array $options Key value array with strings to be converted
     *                       to convolution expressions.
     *
     * @return $this
     */
    public function addConvolveExpressions($options)
    {
        $this->convolves = array_merge($this->convolves, $options);
        return $this;
    }



    /**
     * Image convolution.
     *
     * @param string $options A string with 11 float separated by comma.
     *
     * @return $this
     */
    public function imageConvolution($options = null)
    {
        // Use incoming options or use $this.
        $options = $options ? $options : $this->convolve;

        // Treat incoming as string, split by +
        $this->log("Convolution with '$options'");
        $options = explode(":", $options);

        // Check each option if it matches constant value
        foreach ($options as $option) {
            list($matrix, $divisor, $offset) = $this->createConvolveArguments($option);
            imageconvolution($this->image, $matrix, $divisor, $offset);
        }

        return $this;
    }



    /**
     * Set default background color between 000000-FFFFFF or if using
     * alpha 00000000-FFFFFF7F.
     *
     * @param string $color as hex value.
     *
     * @return $this
    */
    public function setDefaultBackgroundColor($color)
    {
        $this->log("Setting default background color to '$color'.");

        if (!(strlen($color) == 6 || strlen($color) == 8)) {
            throw new Exception(
                "Background color needs a hex value of 6 or 8
                digits. 000000-FFFFFF or 00000000-FFFFFF7F.
                Current value was: '$color'."
            );
        }

        $red    = hexdec(substr($color, 0, 2));
        $green  = hexdec(substr($color, 2, 2));
        $blue   = hexdec(substr($color, 4, 2));

        $alpha = (strlen($color) == 8)
            ? hexdec(substr($color, 6, 2))
            : null;

        if (($red < 0 || $red > 255)
            || ($green < 0 || $green > 255)
            || ($blue < 0 || $blue > 255)
            || ($alpha < 0 || $alpha > 127)
        ) {
            throw new Exception(
                "Background color out of range. Red, green blue
                should be 00-FF and alpha should be 00-7F.
                Current value was: '$color'."
            );
        }

        $this->bgColor = strtolower($color);
        $this->bgColorDefault = array(
            'red'   => $red,
            'green' => $green,
            'blue'  => $blue,
            'alpha' => $alpha
        );

        return $this;
    }



    /**
     * Get the background color.
     *
     * @param resource $img the image to work with or null if using $this->image.
     *
     * @return color value or null if no background color is set.
    */
    private function getBackgroundColor($img = null)
    {
        $img = isset($img) ? $img : $this->image;

        if ($this->bgColorDefault) {

            $red   = $this->bgColorDefault['red'];
            $green = $this->bgColorDefault['green'];
            $blue  = $this->bgColorDefault['blue'];
            $alpha = $this->bgColorDefault['alpha'];

            if ($alpha) {
                $color = imagecolorallocatealpha($img, $red, $green, $blue, $alpha);
            } else {
                $color = imagecolorallocate($img, $red, $green, $blue);
            }

            return $color;

        } else {
            return 0;
        }
    }



    /**
     * Create a image and keep transparency for png and gifs.
     *
     * @param int $width of the new image.
     * @param int $height of the new image.
     *
     * @return image resource.
    */
    private function createImageKeepTransparency($width, $height)
    {
        $this->log("Creating a new working image width={$width}px, height={$height}px.");
        $img = imagecreatetruecolor($width, $height);
        imagealphablending($img, false);
        imagesavealpha($img, true);

        if ($this->bgColorDefault) {

            $color = $this->getBackgroundColor($img);
            imagefill($img, 0, 0, $color);
            $this->Log("Filling image with background color.");
        }

        return $img;
    }



    /**
     * Set optimizing  and post-processing options.
     *
     * @param array $options with config for postprocessing with external tools.
     *
     * @return $this
     */
    public function setPostProcessingOptions($options)
    {
        if (isset($options['jpeg_optimize']) && $options['jpeg_optimize']) {
            $this->jpegOptimizeCmd = $options['jpeg_optimize_cmd'];
        } else {
            $this->jpegOptimizeCmd = null;
        }

        if (isset($options['png_filter']) && $options['png_filter']) {
            $this->pngFilterCmd = $options['png_filter_cmd'];
        } else {
            $this->pngFilterCmd = null;
        }

        if (isset($options['png_deflate']) && $options['png_deflate']) {
            $this->pngDeflateCmd = $options['png_deflate_cmd'];
        } else {
            $this->pngDeflateCmd = null;
        }

        return $this;
    }



    /**
     * Save image.
     *
     * @param string $src  as target filename.
     * @param string $base as base directory where to store images.
     *
     * @return $this or false if no folder is set.
     */
    public function save($src = null, $base = null)
    {
        if (isset($src)) {
            $this->setTarget($src, $base);
        }

        is_writable($this->saveFolder)
            or $this->raiseError('Target directory is not writable.');

        switch(strtolower($this->extension)) {

            case 'jpeg':
            case 'jpg':
                $this->Log("Saving image as JPEG to cache using quality = {$this->quality}.");
                imagejpeg($this->image, $this->cacheFileName, $this->quality);

                // Use JPEG optimize if defined
                if ($this->jpegOptimizeCmd) {
                    if ($this->verbose) {
                        clearstatcache();
                        $this->log("Filesize before optimize: " . filesize($this->cacheFileName) . " bytes.");
                    }
                    $res = array();
                    $cmd = $this->jpegOptimizeCmd . " -outfile $this->cacheFileName $this->cacheFileName";
                    exec($cmd, $res);
                    $this->log($cmd);
                    $this->log($res);
                }
                break;

            case 'gif':
                $this->Log("Saving image as GIF to cache.");
                imagegif($this->image, $this->cacheFileName);
                break;

            case 'png':
                $this->Log("Saving image as PNG to cache using compression = {$this->compress}.");

                // Turn off alpha blending and set alpha flag
                imagealphablending($this->image, false);
                imagesavealpha($this->image, true);
                imagepng($this->image, $this->cacheFileName, $this->compress);

                // Use external program to filter PNG, if defined
                if ($this->pngFilterCmd) {
                    if ($this->verbose) {
                        clearstatcache();
                        $this->Log("Filesize before filter optimize: " . filesize($this->cacheFileName) . " bytes.");
                    }
                    $res = array();
                    $cmd = $this->pngFilterCmd . " $this->cacheFileName";
                    exec($cmd, $res);
                    $this->Log($cmd);
                    $this->Log($res);
                }

                // Use external program to deflate PNG, if defined
                if ($this->pngDeflateCmd) {
                    if ($this->verbose) {
                        clearstatcache();
                        $this->Log("Filesize before deflate optimize: " . filesize($this->cacheFileName) . " bytes.");
                    }
                    $res = array();
                    $cmd = $this->pngDeflateCmd . " $this->cacheFileName";
                    exec($cmd, $res);
                    $this->Log($cmd);
                    $this->Log($res);
                }
                break;

            default:
                $this->RaiseError('No support for this file extension.');
                break;
        }

        if ($this->verbose) {
            clearstatcache();
            $this->log("Cached image filesize: " . filesize($this->cacheFileName) . " bytes.");
            $this->log("imageistruecolor() : " . (imageistruecolor($this->image) ? 'true' : 'false'));
            $this->log("imagecolorstotal() : " . imagecolorstotal($this->image));
            $this->log("Number of colors in image = " . $this->ColorsTotal($this->image));
        }

        return $this;
    }



    /**
     * Output image to browser using caching.
     *
     * @param string $file   to read and output, default is to use $this->cacheFileName
     * @param string $format set to json to output file as json object with details
     *
     * @return void
     */
    public function output($file = null, $format = null)
    {
        if (is_null($file)) {
            $file = $this->cacheFileName;
        }

        if (is_null($format)) {
            $format = $this->outputFormat;
        }

        $this->log("Output format is: $format");

        if (!$this->verbose && $format == 'json') {
            header('Content-type: application/json');
            echo $this->json($file);
            exit;
        }

        $this->log("Outputting image: $file");

        // Get image modification time
        clearstatcache();
        $lastModified = filemtime($file);
        $gmdate = gmdate("D, d M Y H:i:s", $lastModified);

        if (!$this->verbose) {
            header('Last-Modified: ' . $gmdate . " GMT");
        }

        if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) && strtotime($_SERVER['HTTP_IF_MODIFIED_SINCE']) == $lastModified) {

            if ($this->verbose) {
                $this->log("304 not modified");
                $this->verboseOutput();
                exit;
            }

            header("HTTP/1.0 304 Not Modified");

        } else {

            if ($this->verbose) {
                $this->log("Last modified: " . $gmdate . " GMT");
                $this->verboseOutput();
                exit;
            }

            // Get details on image
            $info = getimagesize($file);
            !empty($info) or $this->raiseError("The file doesn't seem to be an image.");
            $mime = $info['mime'];

            header('Content-type: ' . $mime);
            readfile($file);
        }

        exit;
    }



    /**
     * Create a JSON object from the image details.
     *
     * @param string $file the file to output.
     *
     * @return string json-encoded representation of the image.
     */
    public function json($file = null)
    {
        $file = $file ? $file : $this->cacheFileName;

        $details = array();

        clearstatcache();

        $details['src']        = $this->imageSrc;
        $lastModified          = filemtime($this->pathToImage);
        $details['srcGmdate'] = gmdate("D, d M Y H:i:s", $lastModified);

        $details['cache']        = basename($this->cacheFileName);
        $lastModified            = filemtime($this->cacheFileName);
        $details['cacheGmdate'] = gmdate("D, d M Y H:i:s", $lastModified);

        $this->loadImageDetails($file);

        $details['filename'] = basename($file);
        $details['width']  = $this->width;
        $details['height'] = $this->height;
        $details['aspectRatio'] = round($this->width / $this->height, 3);
        $details['size'] = filesize($file);

        $this->load($file);
        $details['colors'] = $this->colorsTotal($this->image);

        $options = null;
        if (defined("JSON_PRETTY_PRINT") && defined("JSON_UNESCAPED_SLASHES")) {
            $options = JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES;
        }

        return json_encode($details, $options);
    }



    /**
     * Log an event if verbose mode.
     *
     * @param string $message to log.
     *
     * @return this
     */
    public function log($message)
    {
        if ($this->verbose) {
            $this->log[] = $message;
        }

        return $this;
    }



    /**
     * Do verbose output and print out the log and the actual images.
     *
     * @return void
     */
    private function verboseOutput()
    {
        $log = null;
        $this->log("As JSON: \n" . $this->json());
        $this->log("Memory peak: " . round(memory_get_peak_usage() /1024/1024) . "M");
        $this->log("Memory limit: " . ini_get('memory_limit'));

        $included = get_included_files();
        $this->log("Included files: " . count($included));

        foreach ($this->log as $val) {
            if (is_array($val)) {
                foreach ($val as $val1) {
                    $log .= htmlentities($val1) . '<br/>';
                }
            } else {
                $log .= htmlentities($val) . '<br/>';
            }
        }

        echo <<<EOD
<!doctype html>
<html lang=en>
<meta charset=utf-8>
<title>CImage verbose output</title>
<style>body{background-color: #ddd}</style>
<h1>CImage Verbose Output</h1>
<pre>{$log}</pre>
EOD;
    }



    /**
     * Raise error, enables to implement a selection of error methods.
     *
     * @param string $message the error message to display.
     *
     * @return void
     * @throws Exception
     */
    private function raiseError($message)
    {
        throw new Exception($message);
    }
}