Enable to set JPEG image as interlaced, implement feature #177.

fixed markdown syntax

CImage.php

@@ -423,6 +423,13 @@ class CImage
 
 
 
+    /*
+     * Use interlaced progressive mode for JPEG images.
+     */
+    private $interlace = false;
+
+
+
     /*
      * Image copy strategy, defaults to RESAMPLE.
      */
@@ -838,6 +845,7 @@ class CImage
             'blur'        => null,
             'convolve'       => null,
             'rotateAfter' => null,
+            'interlace' => null,
 
             // Output format
             'outputFormat' => null,
@@ -1023,13 +1031,15 @@ class CImage
         $this->log("Init dimension (before) newWidth x newHeight is {$this->newWidth} x {$this->newHeight}.");
 
         // width as %
-        if ($this->newWidth[strlen($this->newWidth)-1] == '%') {
+        if ($this->newWidth
+            && $this->newWidth[strlen($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] == '%') {
+        if ($this->newHeight
+            && $this->newHeight[strlen($this->newHeight)-1] == '%') {
             $this->newHeight = $this->height * substr($this->newHeight, 0, -1) / 100;
             $this->log("Setting new height based on % to {$this->newHeight}");
         }
@@ -1365,6 +1375,7 @@ class CImage
             && !$this->autoRotate
             && !$this->bgColor
             && ($this->upscale === self::UPSCALE_DEFAULT)
+            && !$this->lossy
         ) {
             $this->log("Using original image.");
             $this->output($this->pathToImage);
@@ -1399,6 +1410,7 @@ class CImage
         $rotateBefore = $this->rotateBefore ? "_rb{$this->rotateBefore}" : null;
         $rotateAfter  = $this->rotateAfter  ? "_ra{$this->rotateAfter}"  : null;
         $lossy        = $this->lossy        ? "_l"                       : null;
+        $interlace    = $this->interlace    ? "_i"                       : null;
 
         $saveAs = $this->normalizeFileExtension();
         $saveAs = $saveAs ? "_$saveAs" : null;
@@ -1465,7 +1477,7 @@ class CImage
             . $quality . $filters . $sharpen . $emboss . $blur . $palette
             . $optimize . $compress
             . $scale . $rotateBefore . $rotateAfter . $autoRotate . $bgColor
-            . $convolve . $copyStrat . $lossy . $saveAs;
+            . $convolve . $copyStrat . $lossy . $interlace . $saveAs;
 
         return $this->setTarget($file, $base);
     }
@@ -2437,6 +2449,12 @@ class CImage
 
             case 'jpeg':
             case 'jpg':
+                // Set as interlaced progressive JPEG
+                if ($this->interlace) {
+                    $this->Log("Set JPEG image to be interlaced.");
+                    $res = imageinterlace($this->image, true);
+                }
+
                 $this->Log("Saving image as JPEG to cache using quality = {$this->quality}.");
                 imagejpeg($this->image, $this->cacheFileName, $this->quality);
 

README.md

@@ -49,14 +49,14 @@ There are several ways of installing. You either install the whole project which
 
 The [sourcode is available on GitHub](https://github.com/mosbth/cimage). Clone, fork or [download as zip](https://github.com/mosbth/cimage/archive/master.zip). 
 
-**Latest stable version is v0.7.17 released 2016-08-09.**
+**Latest stable version is v0.7.18 released 2016-08-09.**
 
 I prefer cloning like this. Do switch to the latest stable version.
 
 ```bash
 git clone git://github.com/mosbth/cimage.git
 cd cimage
-git checkout v0.7.17
+git checkout v0.7.18
 ```
 
 Make the cache-directory writable by the webserver.
@@ -79,7 +79,7 @@ There are some all-included bundles of `img.php` that can be downloaded and used
 Dowload the version of your choice like this.
 
 ```bash
-wget https://raw.githubusercontent.com/mosbth/cimage/v0.7.17/webroot/imgp.php
+wget https://raw.githubusercontent.com/mosbth/cimage/v0.7.18/webroot/imgp.php
 ```
 
 Open up the file in your editor and edit the array `$config`. Ensure that the paths to the image directory and the cache directory matches your environment, or create an own config-file for the script.

REVISION.md

@@ -5,6 +5,56 @@ Revision history
 [![Build Status](https://scrutinizer-ci.com/g/mosbth/cimage/badges/build.png?b=master)](https://scrutinizer-ci.com/g/mosbth/cimage/build-status/master)
 
 
+v0.8.0 (2020-06-08)
+-------------------------------------
+
+* Enable to set JPEG image as interlaced, implement feature #177.
+* Add function getValue() to read from querystring.
+* Set PHP 7.0 as precondition (to prepare to update the codebase).
+
+
+
+v0.7.23 (2020-05-06)
+-------------------------------------
+
+* Fix error in composer.json
+
+
+
+v0.7.22 (2020-05-06)
+-------------------------------------
+
+* Update composer.json and move ext-gd from required to suggested to ease installation where cli does not have all extensions installed.
+
+
+
+v0.7.21 (2020-01-15)
+-------------------------------------
+
+* Support PHP 7.4, some minor fixes with notices.
+
+
+v0.7.20 (2017-11-06)
+-------------------------------------
+
+* Remove webroot/img/{round8.PNG,wider.JPEG,wider.JPG} to avoid unzip warning message when installing with composer.
+* Adding docker-compose.yml #169.
+
+
+v0.7.19 (2017-03-31)
+-------------------------------------
+
+* Move exception handler from functions.php to img.php #166.
+* Correct XSS injection in `check_system.php`.
+* Composer suggests ext-imagick and ext-curl.
+
+
+v0.7.18 (2016-08-09)
+-------------------------------------
+
+* Made `&lossless` a requirement to not use the original image.
+
+
 v0.7.17 (2016-08-09)
 -------------------------------------
 

composer.json

@@ -18,11 +18,13 @@
         "docs": "http://dbwebb.se/opensource/cimage"
     },
     "require": {
-        "php": ">=5.3",
-        "ext-gd": "*"
+        "php": ">=7.0"
     },
     "suggest": {
-        "ext-exif": "*"
+        "ext-curl": "*",
+        "ext-exif": "*",
+        "ext-gd": "*",
+        "ext-imagick": "*"
     },
     "autoload": {
        "files": [

defines.php

@@ -1,6 +1,6 @@
 <?php
 // Version of cimage and img.php
-define("CIMAGE_VERSION", "v0.7.17 (2016-08-09)");
+define("CIMAGE_VERSION", "v0.7.23 (2020-05-06)");
 
 // For CRemoteImage
 define("CIMAGE_USER_AGENT", "CImage/" . CIMAGE_VERSION);

docker-compose.yml

@@ -0,0 +1,30 @@
+version: "3"
+services:
+    php74:
+        image: anax/dev:php74-apache
+        ports:
+            - "8074:80"
+        volumes:
+            - .:/home/anax/repo
+
+    php71:
+        image: cimage/php71-apache:latest
+        #build: .
+        ports:
+            - "8071:80"
+        volumes:
+            - ./:/var/www/html/
+    php70:
+        image: cimage/php70-apache:latest
+        #build: .
+        ports:
+            - "8070:80"
+        volumes:
+            - .:/var/www/html
+    php56:
+        image: cimage/php56-apache:latest
+        #build: .
+        ports:
+            - "8056:80"
+        volumes:
+            - .:/var/www/html

functions.php

@@ -67,22 +67,6 @@ function errorPage($msg, $type = 500)
 
 
 
-/**
- * Custom exception handler.
- */
-set_exception_handler(function ($exception) {
-    errorPage(
-        "<p><b>img.php: Uncaught exception:</b> <p>"
-        . $exception->getMessage()
-        . "</p><pre>"
-        . $exception->getTraceAsString()
-        . "</pre>",
-        500
-    );
-});
-
-
-
 /**
  * Get input from query string or return default value if not set.
  *
@@ -123,6 +107,25 @@ function getDefined($key, $defined, $undefined)
 
 
 
+/**
+ * Get value of input from query string or else $undefined.
+ *
+ * @param mixed $key       as string or array of string values to look for in $_GET.
+ * @param mixed $undefined value to return when $key has no, or empty value in $_GET.
+ *
+ * @return mixed value as or $undefined.
+ */
+function getValue($key, $undefined)
+{
+    $val = get($key);
+    if (is_null($val) || $val === "") {
+        return $undefined;
+    }
+    return $val;
+}
+
+
+
 /**
  * Get value from config array or default if key is not set in config array.
  *
@@ -148,7 +151,7 @@ function getConfig($key, $default)
  *
  * @return void or array.
  */
-function verbose($msg = null)
+function verbose($msg = null, $arg = "")
 {
     global $verbose, $verboseFile;
     static $log = array();
@@ -161,7 +164,15 @@ function verbose($msg = null)
         return $log;
     }
 
-    $log[] = $msg;
+    if (is_null($arg)) {
+        $arg = "null";
+    } elseif ($arg === false) {
+        $arg = "false";
+    } elseif ($arg === true) {
+        $arg = "true";
+    }
+
+    $log[] = $msg . $arg;
 }
 
 

webroot/check_system.php

@@ -2,7 +2,7 @@
 
 echo 'Current PHP version: ' . phpversion() . '<br><br>';
 
-echo 'Running on: ' . $_SERVER['SERVER_SOFTWARE'] . '<br><br>';
+echo 'Running on: ' . htmlentities($_SERVER['SERVER_SOFTWARE']) . '<br><br>';
 
 $no = extension_loaded('exif') ? null : 'NOT';
 echo "Extension exif is $no loaded.<br>";

webroot/img.php

@@ -8,6 +8,22 @@
  *
  */
 
+/**
+ * Custom exception handler.
+ */
+set_exception_handler(function ($exception) {
+    errorPage(
+        "<p><b>img.php: Uncaught exception:</b> <p>"
+        . $exception->getMessage()
+        . "</p><pre>"
+        . $exception->getTraceAsString()
+        . "</pre>",
+        500
+    );
+});
+
+
+
 /**
  * Get configuration options from file, if the file exists, else use $config
  * if its defined or create an empty $config.
@@ -424,7 +440,7 @@ if (isset($sizes[$newWidth])) {
 }
 
 // Support width as % of original width
-if ($newWidth[strlen($newWidth)-1] == '%') {
+if ($newWidth && $newWidth[strlen($newWidth)-1] == '%') {
     is_numeric(substr($newWidth, 0, -1))
         or errorPage('Width % not numeric.', 404);
 } else {
@@ -449,7 +465,7 @@ if (isset($sizes[$newHeight])) {
 }
 
 // height
-if ($newHeight[strlen($newHeight)-1] == '%') {
+if ($newHeight && $newHeight[strlen($newHeight)-1] == '%') {
     is_numeric(substr($newHeight, 0, -1))
         or errorPage('Height % out of range.', 404);
 } else {
@@ -480,7 +496,7 @@ $aspectRatioConstant = getConfig('aspect_ratio_constant', function () {
 
 // Check to replace predefined aspect ratio
 $aspectRatios = call_user_func($aspectRatioConstant);
-$negateAspectRatio = ($aspectRatio[0] == '!') ? true : false;
+$negateAspectRatio = ($aspectRatio && $aspectRatio[0] == '!') ? true : false;
 $aspectRatio = $negateAspectRatio ? substr($aspectRatio, 1) : $aspectRatio;
 
 if (isset($aspectRatios[$aspectRatio])) {
@@ -904,6 +920,18 @@ if ($cacheControl) {
 
 
 
+/**
+ * interlace - Enable configuration for interlaced progressive JPEG images.
+ */
+$interlaceConfig  = getConfig('interlace', null);
+$interlaceValue   = getValue('interlace', null);
+$interlaceDefined = getDefined('interlace', true, null);
+$interlace = $interlaceValue ?? $interlaceDefined ?? $interlaceConfig;
+verbose("interlace (configfile) = ", $interlaceConfig);
+verbose("interlace = ", $interlace);
+
+
+
 /**
  * Prepare a dummy image and use it as source image.
  */
@@ -1065,6 +1093,7 @@ if (is_callable($hookBeforeCImage)) {
             'blur'      => $blur,
             'convolve'  => $convolve,
             'rotateAfter' => $rotateAfter,
+            'interlace' => $interlace,
 
             // Output format
             'outputFormat' => $outputFormat,
@@ -1153,6 +1182,7 @@ $img->log("Incoming arguments: " . print_r(verbose(), 1))
             'blur'      => $blur,
             'convolve'  => $convolve,
             'rotateAfter' => $rotateAfter,
+            'interlace' => $interlace,
 
             // Output format
             'outputFormat' => $outputFormat,

webroot/img_config.php

@@ -41,7 +41,7 @@ return array(
      *  mode: 'production'
      */
      //'mode' => 'production',
-     //'mode' => 'development',
+     'mode' => 'development',
      //'mode' => 'strict',
 
 
@@ -67,7 +67,7 @@ return array(
      */
     'image_path'        =>  __DIR__ . '/img/',
     'cache_path'        =>  __DIR__ . '/../cache/',
-    //'alias_path'   =>  __DIR__ . '/img/alias/',
+    'alias_path'   =>  __DIR__ . '/img/alias/',
 
 
 
@@ -116,7 +116,7 @@ return array(
      *  password_type:   'text' // use plain password, not encoded,
      */
     //'password_always' => false, // always require password,
-    //'password'        => false, // "secret-password",
+    'password'        => "moped", // "secret-password",
     //'password_type'   => 'text', // supports 'text', 'md5', 'hash',
 
 
@@ -485,6 +485,17 @@ return array(
             "scale" => 14,
             "luminanceStrategy" => 3,
             "customCharacterSet" => null,
-        );
-    },*/
+        ), */
+
+
+
+    /**
+     * Default options using interlaced progressive JPEG images. Set to true to
+     * always render jpeg images as interlaced. This setting can be overridden
+     * by using `?interlace=true` or `?interlace=false`.
+     *
+     * Default values are:
+     *  interlace:  false
+     */
+     /*'interlace' => false,*/
 );

webroot/imgd.php

@@ -38,7 +38,7 @@ $config = array(
 
 
 // Version of cimage and img.php
-define("CIMAGE_VERSION", "v0.7.17 (2016-08-09)");
+define("CIMAGE_VERSION", "v0.7.23 (2020-05-06)");
 
 // For CRemoteImage
 define("CIMAGE_USER_AGENT", "CImage/" . CIMAGE_VERSION);
@@ -118,22 +118,6 @@ function errorPage($msg, $type = 500)
 
 
 
-/**
- * Custom exception handler.
- */
-set_exception_handler(function ($exception) {
-    errorPage(
-        "<p><b>img.php: Uncaught exception:</b> <p>"
-        . $exception->getMessage()
-        . "</p><pre>"
-        . $exception->getTraceAsString()
-        . "</pre>",
-        500
-    );
-});
-
-
-
 /**
  * Get input from query string or return default value if not set.
  *
@@ -174,6 +158,25 @@ function getDefined($key, $defined, $undefined)
 
 
 
+/**
+ * Get value of input from query string or else $undefined.
+ *
+ * @param mixed $key       as string or array of string values to look for in $_GET.
+ * @param mixed $undefined value to return when $key has no, or empty value in $_GET.
+ *
+ * @return mixed value as or $undefined.
+ */
+function getValue($key, $undefined)
+{
+    $val = get($key);
+    if (is_null($val) || $val === "") {
+        return $undefined;
+    }
+    return $val;
+}
+
+
+
 /**
  * Get value from config array or default if key is not set in config array.
  *
@@ -199,7 +202,7 @@ function getConfig($key, $default)
  *
  * @return void or array.
  */
-function verbose($msg = null)
+function verbose($msg = null, $arg = "")
 {
     global $verbose, $verboseFile;
     static $log = array();
@@ -212,7 +215,15 @@ function verbose($msg = null)
         return $log;
     }
 
-    $log[] = $msg;
+    if (is_null($arg)) {
+        $arg = "null";
+    } elseif ($arg === false) {
+        $arg = "false";
+    } elseif ($arg === true) {
+        $arg = "true";
+    }
+
+    $log[] = $msg . $arg;
 }
 
 
@@ -1549,6 +1560,13 @@ class CImage
 
 
 
+    /*
+     * Use interlaced progressive mode for JPEG images.
+     */
+    private $interlace = false;
+
+
+
     /*
      * Image copy strategy, defaults to RESAMPLE.
      */
@@ -1964,6 +1982,7 @@ class CImage
             'blur'        => null,
             'convolve'       => null,
             'rotateAfter' => null,
+            'interlace' => null,
 
             // Output format
             'outputFormat' => null,
@@ -2149,13 +2168,15 @@ class CImage
         $this->log("Init dimension (before) newWidth x newHeight is {$this->newWidth} x {$this->newHeight}.");
 
         // width as %
-        if ($this->newWidth[strlen($this->newWidth)-1] == '%') {
+        if ($this->newWidth
+            && $this->newWidth[strlen($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] == '%') {
+        if ($this->newHeight
+            && $this->newHeight[strlen($this->newHeight)-1] == '%') {
             $this->newHeight = $this->height * substr($this->newHeight, 0, -1) / 100;
             $this->log("Setting new height based on % to {$this->newHeight}");
         }
@@ -2491,6 +2512,7 @@ class CImage
             && !$this->autoRotate
             && !$this->bgColor
             && ($this->upscale === self::UPSCALE_DEFAULT)
+            && !$this->lossy
         ) {
             $this->log("Using original image.");
             $this->output($this->pathToImage);
@@ -2525,6 +2547,7 @@ class CImage
         $rotateBefore = $this->rotateBefore ? "_rb{$this->rotateBefore}" : null;
         $rotateAfter  = $this->rotateAfter  ? "_ra{$this->rotateAfter}"  : null;
         $lossy        = $this->lossy        ? "_l"                       : null;
+        $interlace    = $this->interlace    ? "_i"                       : null;
 
         $saveAs = $this->normalizeFileExtension();
         $saveAs = $saveAs ? "_$saveAs" : null;
@@ -2591,7 +2614,7 @@ class CImage
             . $quality . $filters . $sharpen . $emboss . $blur . $palette
             . $optimize . $compress
             . $scale . $rotateBefore . $rotateAfter . $autoRotate . $bgColor
-            . $convolve . $copyStrat . $lossy . $saveAs;
+            . $convolve . $copyStrat . $lossy . $interlace . $saveAs;
 
         return $this->setTarget($file, $base);
     }
@@ -3563,6 +3586,12 @@ class CImage
 
             case 'jpeg':
             case 'jpg':
+                // Set as interlaced progressive JPEG
+                if ($this->interlace) {
+                    $this->Log("Set JPEG image to be interlaced.");
+                    $res = imageinterlace($this->image, true);
+                }
+
                 $this->Log("Saving image as JPEG to cache using quality = {$this->quality}.");
                 imagejpeg($this->image, $this->cacheFileName, $this->quality);
 
@@ -4417,6 +4446,22 @@ class CFastTrackCache
  *
  */
 
+/**
+ * Custom exception handler.
+ */
+set_exception_handler(function ($exception) {
+    errorPage(
+        "<p><b>img.php: Uncaught exception:</b> <p>"
+        . $exception->getMessage()
+        . "</p><pre>"
+        . $exception->getTraceAsString()
+        . "</pre>",
+        500
+    );
+});
+
+
+
 /**
  * Get configuration options from file, if the file exists, else use $config
  * if its defined or create an empty $config.
@@ -4833,7 +4878,7 @@ if (isset($sizes[$newWidth])) {
 }
 
 // Support width as % of original width
-if ($newWidth[strlen($newWidth)-1] == '%') {
+if ($newWidth && $newWidth[strlen($newWidth)-1] == '%') {
     is_numeric(substr($newWidth, 0, -1))
         or errorPage('Width % not numeric.', 404);
 } else {
@@ -4858,7 +4903,7 @@ if (isset($sizes[$newHeight])) {
 }
 
 // height
-if ($newHeight[strlen($newHeight)-1] == '%') {
+if ($newHeight && $newHeight[strlen($newHeight)-1] == '%') {
     is_numeric(substr($newHeight, 0, -1))
         or errorPage('Height % out of range.', 404);
 } else {
@@ -4889,7 +4934,7 @@ $aspectRatioConstant = getConfig('aspect_ratio_constant', function () {
 
 // Check to replace predefined aspect ratio
 $aspectRatios = call_user_func($aspectRatioConstant);
-$negateAspectRatio = ($aspectRatio[0] == '!') ? true : false;
+$negateAspectRatio = ($aspectRatio && $aspectRatio[0] == '!') ? true : false;
 $aspectRatio = $negateAspectRatio ? substr($aspectRatio, 1) : $aspectRatio;
 
 if (isset($aspectRatios[$aspectRatio])) {
@@ -5313,6 +5358,18 @@ if ($cacheControl) {
 
 
 
+/**
+ * interlace - Enable configuration for interlaced progressive JPEG images.
+ */
+$interlaceConfig  = getConfig('interlace', null);
+$interlaceValue   = getValue('interlace', null);
+$interlaceDefined = getDefined('interlace', true, null);
+$interlace = $interlaceValue ?? $interlaceDefined ?? $interlaceConfig;
+verbose("interlace (configfile) = ", $interlaceConfig);
+verbose("interlace = ", $interlace);
+
+
+
 /**
  * Prepare a dummy image and use it as source image.
  */
@@ -5474,6 +5531,7 @@ if (is_callable($hookBeforeCImage)) {
             'blur'      => $blur,
             'convolve'  => $convolve,
             'rotateAfter' => $rotateAfter,
+            'interlace' => $interlace,
 
             // Output format
             'outputFormat' => $outputFormat,
@@ -5562,6 +5620,7 @@ $img->log("Incoming arguments: " . print_r(verbose(), 1))
             'blur'      => $blur,
             'convolve'  => $convolve,
             'rotateAfter' => $rotateAfter,
+            'interlace' => $interlace,
 
             // Output format
             'outputFormat' => $outputFormat,

webroot/imgp.php

@@ -38,7 +38,7 @@ $config = array(
 
 
 // Version of cimage and img.php
-define("CIMAGE_VERSION", "v0.7.17 (2016-08-09)");
+define("CIMAGE_VERSION", "v0.7.23 (2020-05-06)");
 
 // For CRemoteImage
 define("CIMAGE_USER_AGENT", "CImage/" . CIMAGE_VERSION);
@@ -118,22 +118,6 @@ function errorPage($msg, $type = 500)
 
 
 
-/**
- * Custom exception handler.
- */
-set_exception_handler(function ($exception) {
-    errorPage(
-        "<p><b>img.php: Uncaught exception:</b> <p>"
-        . $exception->getMessage()
-        . "</p><pre>"
-        . $exception->getTraceAsString()
-        . "</pre>",
-        500
-    );
-});
-
-
-
 /**
  * Get input from query string or return default value if not set.
  *
@@ -174,6 +158,25 @@ function getDefined($key, $defined, $undefined)
 
 
 
+/**
+ * Get value of input from query string or else $undefined.
+ *
+ * @param mixed $key       as string or array of string values to look for in $_GET.
+ * @param mixed $undefined value to return when $key has no, or empty value in $_GET.
+ *
+ * @return mixed value as or $undefined.
+ */
+function getValue($key, $undefined)
+{
+    $val = get($key);
+    if (is_null($val) || $val === "") {
+        return $undefined;
+    }
+    return $val;
+}
+
+
+
 /**
  * Get value from config array or default if key is not set in config array.
  *
@@ -199,7 +202,7 @@ function getConfig($key, $default)
  *
  * @return void or array.
  */
-function verbose($msg = null)
+function verbose($msg = null, $arg = "")
 {
     global $verbose, $verboseFile;
     static $log = array();
@@ -212,7 +215,15 @@ function verbose($msg = null)
         return $log;
     }
 
-    $log[] = $msg;
+    if (is_null($arg)) {
+        $arg = "null";
+    } elseif ($arg === false) {
+        $arg = "false";
+    } elseif ($arg === true) {
+        $arg = "true";
+    }
+
+    $log[] = $msg . $arg;
 }
 
 
@@ -1549,6 +1560,13 @@ class CImage
 
 
 
+    /*
+     * Use interlaced progressive mode for JPEG images.
+     */
+    private $interlace = false;
+
+
+
     /*
      * Image copy strategy, defaults to RESAMPLE.
      */
@@ -1964,6 +1982,7 @@ class CImage
             'blur'        => null,
             'convolve'       => null,
             'rotateAfter' => null,
+            'interlace' => null,
 
             // Output format
             'outputFormat' => null,
@@ -2149,13 +2168,15 @@ class CImage
         $this->log("Init dimension (before) newWidth x newHeight is {$this->newWidth} x {$this->newHeight}.");
 
         // width as %
-        if ($this->newWidth[strlen($this->newWidth)-1] == '%') {
+        if ($this->newWidth
+            && $this->newWidth[strlen($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] == '%') {
+        if ($this->newHeight
+            && $this->newHeight[strlen($this->newHeight)-1] == '%') {
             $this->newHeight = $this->height * substr($this->newHeight, 0, -1) / 100;
             $this->log("Setting new height based on % to {$this->newHeight}");
         }
@@ -2491,6 +2512,7 @@ class CImage
             && !$this->autoRotate
             && !$this->bgColor
             && ($this->upscale === self::UPSCALE_DEFAULT)
+            && !$this->lossy
         ) {
             $this->log("Using original image.");
             $this->output($this->pathToImage);
@@ -2525,6 +2547,7 @@ class CImage
         $rotateBefore = $this->rotateBefore ? "_rb{$this->rotateBefore}" : null;
         $rotateAfter  = $this->rotateAfter  ? "_ra{$this->rotateAfter}"  : null;
         $lossy        = $this->lossy        ? "_l"                       : null;
+        $interlace    = $this->interlace    ? "_i"                       : null;
 
         $saveAs = $this->normalizeFileExtension();
         $saveAs = $saveAs ? "_$saveAs" : null;
@@ -2591,7 +2614,7 @@ class CImage
             . $quality . $filters . $sharpen . $emboss . $blur . $palette
             . $optimize . $compress
             . $scale . $rotateBefore . $rotateAfter . $autoRotate . $bgColor
-            . $convolve . $copyStrat . $lossy . $saveAs;
+            . $convolve . $copyStrat . $lossy . $interlace . $saveAs;
 
         return $this->setTarget($file, $base);
     }
@@ -3563,6 +3586,12 @@ class CImage
 
             case 'jpeg':
             case 'jpg':
+                // Set as interlaced progressive JPEG
+                if ($this->interlace) {
+                    $this->Log("Set JPEG image to be interlaced.");
+                    $res = imageinterlace($this->image, true);
+                }
+
                 $this->Log("Saving image as JPEG to cache using quality = {$this->quality}.");
                 imagejpeg($this->image, $this->cacheFileName, $this->quality);
 
@@ -4417,6 +4446,22 @@ class CFastTrackCache
  *
  */
 
+/**
+ * Custom exception handler.
+ */
+set_exception_handler(function ($exception) {
+    errorPage(
+        "<p><b>img.php: Uncaught exception:</b> <p>"
+        . $exception->getMessage()
+        . "</p><pre>"
+        . $exception->getTraceAsString()
+        . "</pre>",
+        500
+    );
+});
+
+
+
 /**
  * Get configuration options from file, if the file exists, else use $config
  * if its defined or create an empty $config.
@@ -4833,7 +4878,7 @@ if (isset($sizes[$newWidth])) {
 }
 
 // Support width as % of original width
-if ($newWidth[strlen($newWidth)-1] == '%') {
+if ($newWidth && $newWidth[strlen($newWidth)-1] == '%') {
     is_numeric(substr($newWidth, 0, -1))
         or errorPage('Width % not numeric.', 404);
 } else {
@@ -4858,7 +4903,7 @@ if (isset($sizes[$newHeight])) {
 }
 
 // height
-if ($newHeight[strlen($newHeight)-1] == '%') {
+if ($newHeight && $newHeight[strlen($newHeight)-1] == '%') {
     is_numeric(substr($newHeight, 0, -1))
         or errorPage('Height % out of range.', 404);
 } else {
@@ -4889,7 +4934,7 @@ $aspectRatioConstant = getConfig('aspect_ratio_constant', function () {
 
 // Check to replace predefined aspect ratio
 $aspectRatios = call_user_func($aspectRatioConstant);
-$negateAspectRatio = ($aspectRatio[0] == '!') ? true : false;
+$negateAspectRatio = ($aspectRatio && $aspectRatio[0] == '!') ? true : false;
 $aspectRatio = $negateAspectRatio ? substr($aspectRatio, 1) : $aspectRatio;
 
 if (isset($aspectRatios[$aspectRatio])) {
@@ -5313,6 +5358,18 @@ if ($cacheControl) {
 
 
 
+/**
+ * interlace - Enable configuration for interlaced progressive JPEG images.
+ */
+$interlaceConfig  = getConfig('interlace', null);
+$interlaceValue   = getValue('interlace', null);
+$interlaceDefined = getDefined('interlace', true, null);
+$interlace = $interlaceValue ?? $interlaceDefined ?? $interlaceConfig;
+verbose("interlace (configfile) = ", $interlaceConfig);
+verbose("interlace = ", $interlace);
+
+
+
 /**
  * Prepare a dummy image and use it as source image.
  */
@@ -5474,6 +5531,7 @@ if (is_callable($hookBeforeCImage)) {
             'blur'      => $blur,
             'convolve'  => $convolve,
             'rotateAfter' => $rotateAfter,
+            'interlace' => $interlace,
 
             // Output format
             'outputFormat' => $outputFormat,
@@ -5562,6 +5620,7 @@ $img->log("Incoming arguments: " . print_r(verbose(), 1))
             'blur'      => $blur,
             'convolve'  => $convolve,
             'rotateAfter' => $rotateAfter,
+            'interlace' => $interlace,
 
             // Output format
             'outputFormat' => $outputFormat,