Entropy::area() - Code Metrics - oscarotero/imagecow - Measure and Improve Code Quality continuously with Scrutinizer

Entropy::area() A
last analyzed 2020-01-08 10:30 UTC

↳ Parent: Entropy

Complexity

Conditions	1
Paths	1

Size

Total Lines

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
dl	0
loc	6
rs	10
c	0
b	0
f	0
cc	1
nc	1
nop	1

<?php

namespace Imagecow\Crops;

use Imagick;
use Imagecow\Utils\Color;

/**
 * This class is adapted from Stig Lindqvist's great Crop library:
 * https://github.com/stojg/crop
 * Copyright (c) 2013, Stig Lindqvist.
 *
 * CropEntropy
 *
 * This class finds the a position in the picture with the most energy in it.
 *
 * Energy is in this case calculated by this
 *
 * 1. Take the image and turn it into black and white
 * 2. Run a edge filter so that we're left with only edges.
 * 3. Find a piece in the picture that has the highest entropy (i.e. most edges)
 * 4. Return coordinates that makes sure that this piece of the picture is not cropped 'away'
 */
class Entropy implements CropInterface
{
    const POTENTIAL_RATIO = 1.5;

    /**
     * {@inheritdoc}
     */
    public static function getOffsets(Imagick $original, $targetWidth, $targetHeight)
    {
        $measureImage = clone $original;
        // Enhance edges
        $measureImage->edgeimage(1);
        // Turn image into a grayscale
        $measureImage->modulateImage(100, 0, 100);
        // Turn everything darker than this to pitch black
        $measureImage->blackThresholdImage('#070707');
        // Get the calculated offset for cropping
        return static::getOffsetFromEntropy($measureImage, $targetWidth, $targetHeight);
    }

    /**
     * Get the offset of where the crop should start.
     *
     * @param Imagick $originalImage
     * @param int     $targetHeight
     * @param int     $targetHeight
     *
     * @return array
     */
    protected static function getOffsetFromEntropy(Imagick $originalImage, $targetWidth, $targetHeight)
    {
        // The entropy works better on a blured image
        $image = clone $originalImage;
        $image->blurImage(3, 2);

        $size = $image->getImageGeometry();

        $originalWidth = $size['width'];
        $originalHeight = $size['height'];

        $leftX = static::slice($image, $originalWidth, $targetWidth, 'h');
        $topY = static::slice($image, $originalHeight, $targetHeight, 'v');

        return [$leftX, $topY];
    }

    /**
     * slice.
     *
     * @param mixed $image
     * @param mixed $originalSize
     * @param mixed $targetSize
     * @param mixed $axis         h=horizontal, v = vertical
     */
    protected static function slice($image, $originalSize, $targetSize, $axis)
    {
        $aSlice = null;
        $bSlice = null;

        // Just an arbitrary size of slice size
        $sliceSize = ceil(($originalSize - $targetSize) / 25);

        $aBottom = $originalSize;
        $aTop = 0;

        // while there still are uninvestigated slices of the image
        while (($aBottom - $aTop) > $targetSize) {
            // Make sure that we don't try to slice outside the picture
            $sliceSize = min($aBottom - $aTop - $targetSize, $sliceSize);

            // Make a top slice image
            if (!$aSlice) {

                $aSlice = clone $image;

                if ($axis === 'h') {
                    $aSlice->cropImage($sliceSize, $originalSize, $aTop, 0);
                } else {
                    $aSlice->cropImage($originalSize, $sliceSize, 0, $aTop);
                }
            }

            // Make a bottom slice image
            if (!$bSlice) {

                $bSlice = clone $image;

                if ($axis === 'h') {
                    $bSlice->cropImage($sliceSize, $originalSize, $aBottom - $sliceSize, 0);
                } else {
                    $bSlice->cropImage($originalSize, $sliceSize, 0, $aBottom - $sliceSize);
                }
            }

            // calculate slices potential
            $aPosition = (($axis === 'h') ? 'left' : 'top');
            $bPosition = (($axis === 'h') ? 'right' : 'bottom');

            $aPot = static::getPotential($aPosition, $aTop, $sliceSize);
            $bPot = static::getPotential($bPosition, $aBottom, $sliceSize);

            $canCutA = ($aPot <= 0);
            $canCutB = ($bPot <= 0);

            // if no slices are "cutable", we force if a slice has a lot of potential
            if (!$canCutA && !$canCutB) {
                if (($aPot * self::POTENTIAL_RATIO) < $bPot) {
                    $canCutA = true;
                } elseif ($aPot > ($bPot * self::POTENTIAL_RATIO)) {
                    $canCutB = true;
                }
            }

            // if we can only cut on one side
            if ($canCutA xor $canCutB) {
                if ($canCutA) {
                    $aTop += $sliceSize;
                    $aSlice = null;
                } else {
                    $aBottom -= $sliceSize;
                    $bSlice = null;
                }
            } elseif (static::grayscaleEntropy($aSlice) < static::grayscaleEntropy($bSlice)) {
                // bSlice has more entropy, so remove aSlice and bump aTop down
                $aTop += $sliceSize;
                $aSlice = null;
            } else {
                $aBottom -= $sliceSize;
                $bSlice = null;
            }
        }

        return $aTop;
    }

    /**
     * getSafeZoneList.
     *
     * @return array
     */
    protected static function getSafeZoneList()
    {
        return [];
    }

    /**
     * getPotential.
     *
     * @param mixed $position
     * @param mixed $top
     * @param mixed $sliceSize
     */
    protected static function getPotential($position, $top, $sliceSize)
    {
        if (($position === 'top') || ($position === 'left')) {
            $start = $top;
            $end = $top + $sliceSize;
        } else {
            $start = $top - $sliceSize;
            $end = $top;
        }

        $safeZoneList = static::getSafeZoneList();
        $safeRatio = 0;

        for ($i = $start; $i < $end; ++$i) {
            foreach ($safeZoneList as $safeZone) {
                if (($position === 'top') || ($position === 'bottom')) {
                    if (($safeZone['top'] <= $i) && ($safeZone['bottom'] >= $i)) {

                        $safeRatio = max($safeRatio, ($safeZone['right'] - $safeZone['left']));
                    }
                } elseif (($safeZone['left'] <= $i) && ($safeZone['right'] >= $i)) {

                    $safeRatio = max($safeRatio, ($safeZone['bottom'] - $safeZone['top']));
                }
            }
        }

        return $safeRatio;
    }

    /**
     * Calculate the entropy for this image.
     *
     * A higher value of entropy means more noise / liveliness / color / business
     *
     * @param Imagick $image
     *
     * @return float
     *
     * @see http://brainacle.com/calculating-image-entropy-with-python-how-and-why.html
     * @see http://www.mathworks.com/help/toolbox/images/ref/entropy.html
     */
    protected static function grayscaleEntropy(Imagick $image)
    {
        // The histogram consists of a list of 0-254 and the number of pixels that has that value
        return static::getEntropy($image->getImageHistogram(), static::area($image));
    }

    /**
     * Find out the entropy for a color image.
     *
     * If the source image is in color we need to transform RGB into a grayscale image
     * so we can calculate the entropy more performant.
     *
     * @param Imagick $image
     *
     * @return float
     */
    protected static function colorEntropy(Imagick $image)
    {
        $histogram = $image->getImageHistogram();
        $newHistogram = [];

        // Translates a color histogram into a bw histogram
        $colors = count($histogram);

        for ($idx = 0; $idx < $colors; ++$idx) {
            $colors = $histogram[$idx]->getColor();
            $grey = Color::rgb2bw($colors['r'], $colors['g'], $colors['b']);

            if (isset($newHistogram[$grey])) {
                $newHistogram[$grey] += $histogram[$idx]->getColorCount();
            } else {
                $newHistogram[$grey] = $histogram[$idx]->getColorCount();
            }
        }

        return static::getEntropy($newHistogram, static::area($image));
    }

    /**
     * @param array $histogram - a value[count] array
     * @param int   $area
     *
     * @return float
     */
    protected static function getEntropy($histogram, $area)
    {
        $value = 0.0;
        $colors = count($histogram);

        for ($idx = 0; $idx < $colors; ++$idx) {
            // calculates the percentage of pixels having this color value
            $p = $histogram[$idx]->getColorCount() / $area;
            // A common way of representing entropy in scalar
            $value = $value + $p * log($p, 2);
        }

        // $value is always 0.0 or negative, so transform into positive scalar value
        return -$value;
    }

    /**
     * Get the area in pixels for this image.
     *
     * @param Imagick $image
     *
     * @return int
     */
    protected static function area(Imagick $image)
    {
        $size = $image->getImageGeometry();

        return $size['height'] * $size['width'];
    }
}


1		<?php
2
3		namespace Imagecow\Crops;
4
5		use Imagick;
6		use Imagecow\Utils\Color;
7
8		/**
9		* This class is adapted from Stig Lindqvist's great Crop library:
10		* https://github.com/stojg/crop
11		* Copyright (c) 2013, Stig Lindqvist.
12		*
13		* CropEntropy
14		*
15		* This class finds the a position in the picture with the most energy in it.
16		*
17		* Energy is in this case calculated by this
18		*
19		* 1. Take the image and turn it into black and white
20		* 2. Run a edge filter so that we're left with only edges.
21		* 3. Find a piece in the picture that has the highest entropy (i.e. most edges)
22		* 4. Return coordinates that makes sure that this piece of the picture is not cropped 'away'
23		*/
24		class Entropy implements CropInterface
25		{
26		const POTENTIAL_RATIO = 1.5;
27
28		/**
29		* {@inheritdoc}
30		*/
31	View Code Duplication	public static function getOffsets(Imagick $original, $targetWidth, $targetHeight)
32		{
33		$measureImage = clone $original;
34		// Enhance edges
35		$measureImage->edgeimage(1);
36		// Turn image into a grayscale
37		$measureImage->modulateImage(100, 0, 100);
38		// Turn everything darker than this to pitch black
39		$measureImage->blackThresholdImage('#070707');
40		// Get the calculated offset for cropping
41		return static::getOffsetFromEntropy($measureImage, $targetWidth, $targetHeight);
42		}
43
44		/**
45		* Get the offset of where the crop should start.
46		*
47		* @param Imagick $originalImage
48		* @param int $targetHeight
49		* @param int $targetHeight
50		*
51		* @return array
52		*/
53		protected static function getOffsetFromEntropy(Imagick $originalImage, $targetWidth, $targetHeight)
54		{
55		// The entropy works better on a blured image
56		$image = clone $originalImage;
57		$image->blurImage(3, 2);
58
59		$size = $image->getImageGeometry();
60
61		$originalWidth = $size['width'];
62		$originalHeight = $size['height'];
63
64		$leftX = static::slice($image, $originalWidth, $targetWidth, 'h');
65		$topY = static::slice($image, $originalHeight, $targetHeight, 'v');
66
67		return [$leftX, $topY];
68		}
69
70		/**
71		* slice.
72		*
73		* @param mixed $image
74		* @param mixed $originalSize
75		* @param mixed $targetSize
76		* @param mixed $axis h=horizontal, v = vertical
77		*/
78		protected static function slice($image, $originalSize, $targetSize, $axis)
79		{
80		$aSlice = null;
81		$bSlice = null;
82
83		// Just an arbitrary size of slice size
84		$sliceSize = ceil(($originalSize - $targetSize) / 25);
85
86		$aBottom = $originalSize;
87		$aTop = 0;
88
89		// while there still are uninvestigated slices of the image
90		while (($aBottom - $aTop) > $targetSize) {
91		// Make sure that we don't try to slice outside the picture
92		$sliceSize = min($aBottom - $aTop - $targetSize, $sliceSize);
93
94		// Make a top slice image
95	View Code Duplication	if (!$aSlice) {
		0 ignored issues – show Duplication introduced 2016-01-19 13:39 UTC by Report Bug Copy Issue Report This code seems to be duplicated across your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
96		$aSlice = clone $image;
97
98		if ($axis === 'h') {
99		$aSlice->cropImage($sliceSize, $originalSize, $aTop, 0);
100		} else {
101		$aSlice->cropImage($originalSize, $sliceSize, 0, $aTop);
102		}
103		}
104
105		// Make a bottom slice image
106	View Code Duplication	if (!$bSlice) {
		0 ignored issues – show Duplication introduced 2016-01-19 13:39 UTC by Report Bug Copy Issue Report This code seems to be duplicated across your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
107		$bSlice = clone $image;
108
109		if ($axis === 'h') {
110		$bSlice->cropImage($sliceSize, $originalSize, $aBottom - $sliceSize, 0);
111		} else {
112		$bSlice->cropImage($originalSize, $sliceSize, 0, $aBottom - $sliceSize);
113		}
114		}
115
116		// calculate slices potential
117		$aPosition = (($axis === 'h') ? 'left' : 'top');
118		$bPosition = (($axis === 'h') ? 'right' : 'bottom');
119
120		$aPot = static::getPotential($aPosition, $aTop, $sliceSize);
121		$bPot = static::getPotential($bPosition, $aBottom, $sliceSize);
122
123		$canCutA = ($aPot <= 0);
124		$canCutB = ($bPot <= 0);
125
126		// if no slices are "cutable", we force if a slice has a lot of potential
127		if (!$canCutA && !$canCutB) {
128		if (($aPot * self::POTENTIAL_RATIO) < $bPot) {
129		$canCutA = true;
130		} elseif ($aPot > ($bPot * self::POTENTIAL_RATIO)) {
131		$canCutB = true;
132		}
133		}
134
135		// if we can only cut on one side
136		if ($canCutA xor $canCutB) {
137		if ($canCutA) {
138		$aTop += $sliceSize;
139		$aSlice = null;
140		} else {
141		$aBottom -= $sliceSize;
142		$bSlice = null;
143		}
144		} elseif (static::grayscaleEntropy($aSlice) < static::grayscaleEntropy($bSlice)) {
145		// bSlice has more entropy, so remove aSlice and bump aTop down
146		$aTop += $sliceSize;
147		$aSlice = null;
148		} else {
149		$aBottom -= $sliceSize;
150		$bSlice = null;
151		}
152		}
153
154		return $aTop;
155		}
156
157		/**
158		* getSafeZoneList.
159		*
160		* @return array
161		*/
162		protected static function getSafeZoneList()
163		{
164		return [];
165		}
166
167		/**
168		* getPotential.
169		*
170		* @param mixed $position
171		* @param mixed $top
172		* @param mixed $sliceSize
173		*/
174		protected static function getPotential($position, $top, $sliceSize)
175		{
176		if (($position === 'top') \|\| ($position === 'left')) {
177		$start = $top;
178		$end = $top + $sliceSize;
179		} else {
180		$start = $top - $sliceSize;
181		$end = $top;
182		}
183
184		$safeZoneList = static::getSafeZoneList();
185		$safeRatio = 0;
186
187		for ($i = $start; $i < $end; ++$i) {
188		foreach ($safeZoneList as $safeZone) {
189		if (($position === 'top') \|\| ($position === 'bottom')) {
190	View Code Duplication	if (($safeZone['top'] <= $i) && ($safeZone['bottom'] >= $i)) {
		0 ignored issues – show Duplication introduced 2016-01-19 13:39 UTC by Report Bug Copy Issue Report This code seems to be duplicated across your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
191		$safeRatio = max($safeRatio, ($safeZone['right'] - $safeZone['left']));
192		}
193	View Code Duplication	} elseif (($safeZone['left'] <= $i) && ($safeZone['right'] >= $i)) {
		0 ignored issues – show Duplication introduced 2016-01-19 13:39 UTC by Report Bug Copy Issue Report This code seems to be duplicated across your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
194		$safeRatio = max($safeRatio, ($safeZone['bottom'] - $safeZone['top']));
195		}
196		}
197		}
198
199		return $safeRatio;
200		}
201
202		/**
203		* Calculate the entropy for this image.
204		*
205		* A higher value of entropy means more noise / liveliness / color / business
206		*
207		* @param Imagick $image
208		*
209		* @return float
210		*
211		* @see http://brainacle.com/calculating-image-entropy-with-python-how-and-why.html
212		* @see http://www.mathworks.com/help/toolbox/images/ref/entropy.html
213		*/
214		protected static function grayscaleEntropy(Imagick $image)
215		{
216		// The histogram consists of a list of 0-254 and the number of pixels that has that value
217		return static::getEntropy($image->getImageHistogram(), static::area($image));
218		}
219
220		/**
221		* Find out the entropy for a color image.
222		*
223		* If the source image is in color we need to transform RGB into a grayscale image
224		* so we can calculate the entropy more performant.
225		*
226		* @param Imagick $image
227		*
228		* @return float
229		*/
230		protected static function colorEntropy(Imagick $image)
231		{
232		$histogram = $image->getImageHistogram();
233		$newHistogram = [];
234
235		// Translates a color histogram into a bw histogram
236		$colors = count($histogram);
237
238		for ($idx = 0; $idx < $colors; ++$idx) {
239		$colors = $histogram[$idx]->getColor();
240		$grey = Color::rgb2bw($colors['r'], $colors['g'], $colors['b']);
241
242		if (isset($newHistogram[$grey])) {
243		$newHistogram[$grey] += $histogram[$idx]->getColorCount();
244		} else {
245		$newHistogram[$grey] = $histogram[$idx]->getColorCount();
246		}
247		}
248
249		return static::getEntropy($newHistogram, static::area($image));
250		}
251
252		/**
253		* @param array $histogram - a value[count] array
254		* @param int $area
255		*
256		* @return float
257		*/
258		protected static function getEntropy($histogram, $area)
259		{
260		$value = 0.0;
261		$colors = count($histogram);
262
263		for ($idx = 0; $idx < $colors; ++$idx) {
264		// calculates the percentage of pixels having this color value
265		$p = $histogram[$idx]->getColorCount() / $area;
266		// A common way of representing entropy in scalar
267		$value = $value + $p * log($p, 2);
268		}
269
270		// $value is always 0.0 or negative, so transform into positive scalar value
271		return -$value;
272		}
273
274		/**
275		* Get the area in pixels for this image.
276		*
277		* @param Imagick $image
278		*
279		* @return int
280		*/
281		protected static function area(Imagick $image)
282		{
283		$size = $image->getImageGeometry();
284
285		return $size['height'] * $size['width'];
286		}
287		}
288

oscarotero / imagecow

Entropy::area() A last analyzed 2020-01-08 10:30 UTC

Complexity

Size

Duplication

Importance

Duplication Side-by-Side

Filter issues like

Entropy::area() A
last analyzed 2020-01-08 10:30 UTC