From 2959f11f339ece467db1a22da41b2cf7f119806f Mon Sep 17 00:00:00 2001
From: Mikael Roos <mikael.t.h.roos@gmail.com>
Date: Tue, 1 Sep 2015 16:45:10 +0200
Subject: [PATCH] Adding support for AsciiArt of an image.
---
CAsciiArt.php | 213 +++++++++++++++++++++++++++++++++++++++++
CImage.php | 43 +++++++++
webroot/img.php | 48 +++++++++-
webroot/img_config.php | 21 ++++
4 files changed, 323 insertions(+), 2 deletions(-)
create mode 100644 CAsciiArt.php
diff --git a/CAsciiArt.php b/CAsciiArt.php
new file mode 100644
index 0000000..ac3535b
--- /dev/null
+++ b/CAsciiArt.php
@@ -0,0 +1,213 @@
+<?php
+/**
+ * Create an ASCII version of an image.
+ * Inspired by https://gist.github.com/donatj/1353237 and various sources.
+ *
+ */
+class CAsciiArt
+{
+ /**
+ * Character set to use.
+ */
+ private $characterSet = array(
+ 'one' => "#0XT|:,.' ",
+ 'two' => "@%#*+=-:. ",
+ 'three' => "$@B%8&WM#*oahkbdpqwmZO0QLCJUYXzcvunxrjft/\|()1{}[]?-_+~<>i!lI;:,\"^`'. "
+ );
+
+
+
+ /**
+ * Current character set.
+ */
+ private $characters = null;
+
+
+
+ /**
+ * Length of current character set.
+ */
+ private $charCount = null;
+
+
+
+ /**
+ * Scale of the area to swap to a character.
+ */
+ private $scale = null;
+
+
+
+ /**
+ * Strategy to calculate luminance.
+ */
+ private $luminanceStrategy = null;
+
+
+
+ /**
+ * Constructor which sets default options.
+ */
+ public function __construct()
+ {
+ $this->setOptions();
+ }
+
+
+
+ /**
+ * Add a custom character set.
+ *
+ * @param string $key for the character set.
+ * @param string $value for the character set.
+ *
+ * @return $this
+ */
+ public function addCharacterSet($key, $value)
+ {
+ $this->characterSet[$key] = $value;
+ return $this;
+ }
+
+
+
+ /**
+ * Length of current character set.
+ *
+ * @param array $options to use as default settings.
+ *
+ * @return $this
+ */
+ public function setOptions($options = array())
+ {
+ $default = array(
+ "characterSet" => 'two',
+ "scale" => 14,
+ "luminanceStrategy" => 3,
+ "customCharacterSet" => null,
+ );
+ $default = array_merge($default, $options);
+
+ if (!is_null($default['customCharacterSet'])) {
+ $this->addCharacterSet('custom', $default['customCharacterSet']);
+ $default['characterSet'] = 'custom';
+ }
+
+ $this->scale = $default['scale'];
+ $this->characters = $this->characterSet[$default['characterSet']];
+ $this->charCount = strlen($this->characters);
+ $this->luminanceStrategy = $default['luminanceStrategy'];
+
+ return $this;
+ }
+
+
+
+ /**
+ * Create an Ascii image from an image file.
+ *
+ * @param string $filename of the image to use.
+ *
+ * @return string $ascii with the ASCII image.
+ */
+ public function createFromFile($filename)
+ {
+ $img = imagecreatefromstring(file_get_contents($filename));
+ list($width, $height) = getimagesize($filename);
+
+ $ascii = null;
+ $incY = $this->scale;
+ $incX = $this->scale / 2;
+
+ for ($y = 0; $y < $height - 1; $y += $incY) {
+ for ($x = 0; $x < $width - 1; $x += $incX) {
+ $toX = min($x + $this->scale / 2, $width - 1);
+ $toY = min($y + $this->scale, $height - 1);
+ $luminance = $this->luminanceAreaAverage($img, $x, $y, $toX, $toY);
+ $ascii .= $this->luminance2character($luminance);
+ }
+ $ascii .= PHP_EOL;
+ }
+
+ return $ascii;
+ }
+
+
+
+ /**
+ * Get the luminance from a region of an image using average color value.
+ *
+ * @param string $img the image.
+ * @param integer $x1 the area to get pixels from.
+ * @param integer $y1 the area to get pixels from.
+ * @param integer $x2 the area to get pixels from.
+ * @param integer $y2 the area to get pixels from.
+ *
+ * @return integer $luminance with a value between 0 and 100.
+ */
+ public function luminanceAreaAverage($img, $x1, $y1, $x2, $y2)
+ {
+ $numPixels = ($x2 - $x1 + 1) * ($y2 - $y1 + 1);
+ $luminance = 0;
+
+ for ($x = $x1; $x <= $x2; $x++) {
+ for ($y = $y1; $y <= $y2; $y++) {
+ $rgb = imagecolorat($img, $x, $y);
+ $red = (($rgb >> 16) & 0xFF);
+ $green = (($rgb >> 8) & 0xFF);
+ $blue = ($rgb & 0xFF);
+ $luminance += $this->getLuminance($red, $green, $blue);
+ }
+ }
+
+ return $luminance / $numPixels;
+ }
+
+
+
+ /**
+ * Calculate luminance value with different strategies.
+ *
+ * @param integer $red The color red.
+ * @param integer $green The color green.
+ * @param integer $blue The color blue.
+ *
+ * @return float $luminance with a value between 0 and 1.
+ */
+ public function getLuminance($red, $green, $blue)
+ {
+ switch($this->luminanceStrategy) {
+ case 1:
+ $luminance = ($red * 0.2126 + $green * 0.7152 + $blue * 0.0722) / 255;
+ break;
+ case 2:
+ $luminance = ($red * 0.299 + $green * 0.587 + $blue * 0.114) / 255;
+ break;
+ case 3:
+ $luminance = sqrt(0.299 * pow($red, 2) + 0.587 * pow($green, 2) + 0.114 * pow($blue, 2)) / 255;
+ break;
+ case 0:
+ default:
+ $luminance = ($red + $green + $blue) / (255 * 3);
+ }
+
+ return $luminance;
+ }
+
+
+
+ /**
+ * Translate the luminance value to a character.
+ *
+ * @param string $position a value between 0-100 representing the
+ * luminance.
+ *
+ * @return string with the ascii character.
+ */
+ public function luminance2character($luminance)
+ {
+ $position = (int) round($luminance * ($this->charCount - 1));
+ $char = $this->characters[$position];
+ return $char;
+ }
+}
diff --git a/CImage.php b/CImage.php
index 24be590..80bd97a 100644
--- a/CImage.php
+++ b/CImage.php
@@ -334,6 +334,13 @@ class CImage
+ /*
+ * output to ascii can take som options as an array.
+ */
+ private $asciiOptions = array();
+
+
+
/**
* Properties, the class is mutable and the method setOptions()
* decides (partly) what properties are created.
@@ -2250,6 +2257,10 @@ class CImage
header('Content-type: application/json');
echo $this->json($file);
exit;
+ } elseif ($format == 'ascii') {
+ header('Content-type: text/plain');
+ echo $this->ascii($file);
+ exit;
}
$this->log("Outputting image: $file");
@@ -2341,6 +2352,38 @@ class CImage
+ /**
+ * Set options for creating ascii version of image.
+ *
+ * @param array $options empty to use default or set options to change.
+ *
+ * @return void.
+ */
+ public function setAsciiOptions($options = array())
+ {
+ $this->asciiOptions = $options;
+ }
+
+
+
+ /**
+ * Create an ASCII version from the image details.
+ *
+ * @param string $file the file to output.
+ *
+ * @return string ASCII representation of the image.
+ */
+ public function ascii($file = null)
+ {
+ $file = $file ? $file : $this->cacheFileName;
+
+ $asciiArt = new CAsciiArt();
+ $asciiArt->setOptions($this->asciiOptions);
+ return $asciiArt->createFromFile($file);
+ }
+
+
+
/**
* Log an event if verbose mode.
*
diff --git a/webroot/img.php b/webroot/img.php
index 350c0d8..7efe537 100644
--- a/webroot/img.php
+++ b/webroot/img.php
@@ -754,11 +754,55 @@ verbose("filters = " . print_r($filters, 1));
/**
- * json - output the image as a JSON object with details on the image.
+* json - output the image as a JSON object with details on the image.
+* ascii - output the image as ASCII art.
*/
$outputFormat = getDefined('json', 'json', null);
+$outputFormat = getDefined('ascii', 'ascii', $outputFormat);
+
+verbose("outputformat = $outputFormat");
+
+if ($outputFormat == 'ascii') {
+ $defaultOptions = getConfig(
+ 'ascii-options',
+ array(
+ "characterSet" => 'two',
+ "scale" => 14,
+ "luminanceStrategy" => 3,
+ "customCharacterSet" => null,
+ )
+ );
+ $options = get('ascii');
+ $options = explode(',', $options);
+
+ if (isset($options[0]) && !empty($options[0])) {
+ $defaultOptions['characterSet'] = $options[0];
+ }
+
+ if (isset($options[1]) && !empty($options[1])) {
+ $defaultOptions['scale'] = $options[1];
+ }
+
+ if (isset($options[2]) && !empty($options[2])) {
+ $defaultOptions['luminanceStrategy'] = $options[2];
+ }
+
+ if (count($options) > 3) {
+ // Last option is custom character string
+ unset($options[0]);
+ unset($options[1]);
+ unset($options[2]);
+ $characterString = implode($options);
+ $defaultOptions['customCharacterSet'] = $characterString;
+ }
+
+ //var_dump($options);
+ //var_dump($defaultOptions);
+ //exit;
+
+ $img->setAsciiOptions($defaultOptions);
+}
-verbose("json = $outputFormat");
diff --git a/webroot/img_config.php b/webroot/img_config.php
index d071cac..64223a2 100644
--- a/webroot/img_config.php
+++ b/webroot/img_config.php
@@ -299,4 +299,25 @@ return array(
'golden' => 1.618,
);
},*/
+
+
+
+ /**
+ * default options for ascii image.
+ *
+ * Default values as specified below in the array.
+ * ascii-options:
+ * characterSet: Choose any character set available in CAsciiArt.
+ * scale: How many pixels should each character
+ * translate to.
+ * luminanceStrategy: Choose any strategy available in CAsciiArt.
+ * customCharacterSet: Define your own character set.
+ */
+ /*'ascii-options' => array(
+ "characterSet" => 'two',
+ "scale" => 14,
+ "luminanceStrategy" => 3,
+ "customCharacterSet" => null,
+ );
+ },*/
);