Refactor color reduction to modifer

src/Drivers/Gd/Encoders/BmpEncoder.php

@@ -3,15 +3,13 @@
 namespace Intervention\Image\Drivers\Gd\Encoders;
 
 use Intervention\Image\Drivers\Abstract\Encoders\AbstractEncoder;
-use Intervention\Image\Drivers\Gd\Traits\CanReduceColors;
+use Intervention\Image\Drivers\Gd\Modifiers\LimitColorsModifier;
 use Intervention\Image\EncodedImage;
 use Intervention\Image\Interfaces\EncoderInterface;
 use Intervention\Image\Interfaces\ImageInterface;
 
 class BmpEncoder extends AbstractEncoder implements EncoderInterface
 {
-    use CanReduceColors;
-
     public function __construct(protected int $color_limit = 0)
     {
         //
@@ -19,9 +17,9 @@ class BmpEncoder extends AbstractEncoder implements EncoderInterface
 
     public function encode(ImageInterface $image): EncodedImage
     {
-        $gd = $this->maybeReduceColors($image->frame()->core(), $this->color_limit);
-        $data = $this->getBuffered(function () use ($gd) {
-            imagebmp($gd, null, false);
+        $image = $image->modify(new LimitColorsModifier($this->color_limit));
+        $data = $this->getBuffered(function () use ($image) {
+            imagebmp($image->frame()->core(), null, false);
         });
 
         return new EncodedImage($data, 'image/bmp');

src/Drivers/Gd/Encoders/GifEncoder.php

@@ -4,15 +4,13 @@ namespace Intervention\Image\Drivers\Gd\Encoders;
 
 use Intervention\Gif\Builder as GifBuilder;
 use Intervention\Image\Drivers\Abstract\Encoders\AbstractEncoder;
-use Intervention\Image\Drivers\Gd\Traits\CanReduceColors;
+use Intervention\Image\Drivers\Gd\Modifiers\LimitColorsModifier;
 use Intervention\Image\EncodedImage;
 use Intervention\Image\Interfaces\EncoderInterface;
 use Intervention\Image\Interfaces\ImageInterface;
 
 class GifEncoder extends AbstractEncoder implements EncoderInterface
 {
-    use CanReduceColors;
-
     public function __construct(protected int $color_limit = 0)
     {
         //
@@ -24,9 +22,9 @@ class GifEncoder extends AbstractEncoder implements EncoderInterface
             return $this->encodeAnimated($image);
         }
 
-        $gd = $this->maybeReduceColors($image->frame()->core(), $this->color_limit);
-        $data = $this->getBuffered(function () use ($gd) {
-            imagegif($gd);
+        $image = $image->modify(new LimitColorsModifier($this->color_limit));
+        $data = $this->getBuffered(function () use ($image) {
+            imagegif($image->frame()->core());
         });
 
         return new EncodedImage($data, 'image/gif');

src/Drivers/Gd/Encoders/PngEncoder.php

@@ -3,15 +3,13 @@
 namespace Intervention\Image\Drivers\Gd\Encoders;
 
 use Intervention\Image\Drivers\Abstract\Encoders\AbstractEncoder;
-use Intervention\Image\Drivers\Gd\Traits\CanReduceColors;
+use Intervention\Image\Drivers\Gd\Modifiers\LimitColorsModifier;
 use Intervention\Image\EncodedImage;
 use Intervention\Image\Interfaces\EncoderInterface;
 use Intervention\Image\Interfaces\ImageInterface;
 
 class PngEncoder extends AbstractEncoder implements EncoderInterface
 {
-    use CanReduceColors;
-
     public function __construct(protected int $color_limit = 0)
     {
         //
@@ -19,9 +17,9 @@ class PngEncoder extends AbstractEncoder implements EncoderInterface
 
     public function encode(ImageInterface $image): EncodedImage
     {
-        $gd = $this->maybeReduceColors($image->frame()->core(), $this->color_limit);
-        $data = $this->getBuffered(function () use ($gd) {
-            imagepng($gd, null, -1);
+        $image = $image->modify(new LimitColorsModifier($this->color_limit));
+        $data = $this->getBuffered(function () use ($image) {
+            imagepng($image->frame()->core(), null, -1);
         });
 
         return new EncodedImage($data, 'image/png');

src/Drivers/Gd/Modifiers/LimitColorsModifier.php

@@ -0,0 +1,60 @@
+<?php
+
+namespace Intervention\Image\Drivers\Gd\Modifiers;
+
+use Intervention\Image\Interfaces\ImageInterface;
+use Intervention\Image\Interfaces\ModifierInterface;
+
+class LimitColorsModifier implements ModifierInterface
+{
+    public function __construct(protected int $limit = 0, protected int $threshold = 256)
+    {
+        //
+    }
+
+    public function apply(ImageInterface $image): ImageInterface
+    {
+        // no color limit: no reduction
+        if ($this->limit === 0) {
+            return $image;
+        }
+
+        // limit is over threshold: no reduction
+        if ($this->limit > $this->threshold) {
+            return $image;
+        }
+
+        $width = $image->width();
+        $height = $image->height();
+
+        foreach ($image as $frame) {
+            // create empty gd
+            $reduced = imagecreatetruecolor($width, $height);
+
+            // create matte
+            $matte = imagecolorallocatealpha($reduced, 255, 255, 255, 127);
+
+            // fill with matte
+            imagefill($reduced, 0, 0, $matte);
+
+            imagealphablending($reduced, false);
+
+            // set transparency and get transparency index
+            imagecolortransparent($reduced, $matte);
+
+            // copy original image
+            imagecopy($reduced, $frame->core(), 0, 0, 0, 0, $width, $height);
+
+            // reduce limit by one to include possible transparency in palette
+            $limit = imagecolortransparent($frame->core()) === -1 ? $this->limit : $this->limit - 1;
+
+            // decrease colors
+            imagetruecolortopalette($reduced, true, $limit);
+
+            $frame->setCore($reduced);
+        }
+
+
+        return $image;
+    }
+}

src/Drivers/Gd/Traits/CanReduceColors.php

@@ -1,59 +0,0 @@
-<?php
-
-namespace Intervention\Image\Drivers\Gd\Traits;
-
-use GdImage;
-
-trait CanReduceColors
-{
-    /**
-     * Reduce colors in a given GdImage to the given limit. Reduction is only
-     * applied when the given limit is under the given threshold
-     *
-     * @param GdImage $gd
-     * @param int $limit
-     * @param int $threshold
-     * @return GdImage
-     */
-    private function maybeReduceColors(GdImage $gd, int $limit, int $threshold = 256): GdImage
-    {
-        // no color limit: no reduction
-        if ($limit === 0) {
-            return $gd;
-        }
-
-        // limit is over threshold: no reduction
-        if ($limit > $threshold) {
-            return $gd;
-        }
-
-        // image size
-        $width = imagesx($gd);
-        $height = imagesy($gd);
-
-        // create empty gd
-        $reduced = imagecreatetruecolor($width, $height);
-
-        // create matte
-        $matte = imagecolorallocatealpha($reduced, 255, 255, 255, 127);
-
-        // fill with matte
-        imagefill($reduced, 0, 0, $matte);
-
-        imagealphablending($reduced, false);
-
-        // set transparency and get transparency index
-        imagecolortransparent($reduced, $matte);
-
-        // copy original image
-        imagecopy($reduced, $gd, 0, 0, 0, 0, $width, $height);
-
-        // reduce limit by one to include possible transparency in palette
-        $limit = imagecolortransparent($gd) === -1 ? $limit : $limit - 1;
-
-        // decrease colors
-        imagetruecolortopalette($reduced, true, $limit);
-
-        return $reduced;
-    }
-}

src/Drivers/Imagick/Encoders/BmpEncoder.php

@@ -4,15 +4,13 @@ namespace Intervention\Image\Drivers\Imagick\Encoders;
 
 use Imagick;
 use Intervention\Image\Drivers\Abstract\Encoders\AbstractEncoder;
-use Intervention\Image\Drivers\Imagick\Traits\CanReduceColors;
+use Intervention\Image\Drivers\Imagick\Modifiers\LimitColorsModifier;
 use Intervention\Image\EncodedImage;
 use Intervention\Image\Interfaces\EncoderInterface;
 use Intervention\Image\Interfaces\ImageInterface;
 
 class BmpEncoder extends AbstractEncoder implements EncoderInterface
 {
-    use CanReduceColors;
-
     public function __construct(protected int $color_limit = 0)
     {
         //
@@ -23,12 +21,12 @@ class BmpEncoder extends AbstractEncoder implements EncoderInterface
         $format = 'bmp';
         $compression = Imagick::COMPRESSION_NO;
 
+        $image = $image->modify(new LimitColorsModifier($this->color_limit));
         $imagick = $image->frame()->core();
         $imagick->setFormat($format);
         $imagick->setImageFormat($format);
         $imagick->setCompression($compression);
         $imagick->setImageCompression($compression);
-        $this->maybeReduceColors($imagick, $this->color_limit);
 
         return new EncodedImage($imagick->getImagesBlob(), 'image/bmp');
     }

src/Drivers/Imagick/Encoders/GifEncoder.php

@@ -5,15 +5,16 @@ namespace Intervention\Image\Drivers\Imagick\Encoders;
 use Imagick;
 use Intervention\Image\Drivers\Abstract\Encoders\AbstractEncoder;
 use Intervention\Image\Drivers\Imagick\Image;
-use Intervention\Image\Drivers\Imagick\Traits\CanReduceColors;
+use Intervention\Image\Drivers\Imagick\Modifiers\LimitColorsModifier;
 use Intervention\Image\EncodedImage;
 use Intervention\Image\Exceptions\EncoderException;
 use Intervention\Image\Interfaces\EncoderInterface;
 use Intervention\Image\Interfaces\ImageInterface;
+use Intervention\Image\Traits\CanCheckType;
 
 class GifEncoder extends AbstractEncoder implements EncoderInterface
 {
-    use CanReduceColors;
+    use CanCheckType;
 
     public function __construct(protected int $color_limit = 0)
     {
@@ -29,13 +30,15 @@ class GifEncoder extends AbstractEncoder implements EncoderInterface
             throw new EncoderException('Image does not match the current driver.');
         }
 
+        $image = $this->failIfNotClass($image, Image::class);
+
+        $image = $image->modify(new LimitColorsModifier($this->color_limit));
         $imagick = $image->getImagick();
         $imagick->setFormat($format);
         $imagick->setImageFormat($format);
         $imagick->setCompression($compression);
         $imagick->setImageCompression($compression);
         $imagick->optimizeImageLayers();
-        $this->maybeReduceColors($imagick, $this->color_limit);
         $imagick = $imagick->deconstructImages();
 
         return new EncodedImage($imagick->getImagesBlob(), 'image/gif');

src/Drivers/Imagick/Encoders/PngEncoder.php

@@ -4,15 +4,13 @@ namespace Intervention\Image\Drivers\Imagick\Encoders;
 
 use Imagick;
 use Intervention\Image\Drivers\Abstract\Encoders\AbstractEncoder;
-use Intervention\Image\Drivers\Imagick\Traits\CanReduceColors;
+use Intervention\Image\Drivers\Imagick\Modifiers\LimitColorsModifier;
 use Intervention\Image\EncodedImage;
 use Intervention\Image\Interfaces\EncoderInterface;
 use Intervention\Image\Interfaces\ImageInterface;
 
 class PngEncoder extends AbstractEncoder implements EncoderInterface
 {
-    use CanReduceColors;
-
     public function __construct(protected int $color_limit = 0)
     {
         //
@@ -23,12 +21,12 @@ class PngEncoder extends AbstractEncoder implements EncoderInterface
         $format = 'png';
         $compression = Imagick::COMPRESSION_ZIP;
 
+        $image = $image->modify(new LimitColorsModifier($this->color_limit));
         $imagick = $image->frame()->core();
         $imagick->setFormat($format);
         $imagick->setImageFormat($format);
         $imagick->setCompression($compression);
         $imagick->setImageCompression($compression);
-        $this->maybeReduceColors($imagick, $this->color_limit);
 
         return new EncodedImage($imagick->getImagesBlob(), 'image/png');
     }

src/Drivers/Imagick/Modifiers/LimitColorsModifier.php

@@ -0,0 +1,44 @@
+<?php
+
+namespace Intervention\Image\Drivers\Imagick\Modifiers;
+
+use Intervention\Image\Interfaces\ImageInterface;
+use Intervention\Image\Interfaces\ModifierInterface;
+use Intervention\Image\Traits\CanCheckType;
+use Intervention\Image\Drivers\Imagick\Image;
+
+class LimitColorsModifier implements ModifierInterface
+{
+    use CanCheckType;
+
+    public function __construct(protected int $limit = 0, protected $threshold = 256)
+    {
+        //
+    }
+
+    public function apply(ImageInterface $image): ImageInterface
+    {
+        // no color limit: no reduction
+        if ($this->limit === 0) {
+            return $image;
+        }
+
+        // limit is over threshold: no reduction
+        if ($this->limit > $this->threshold) {
+            return $image;
+        }
+
+        $image = $this->failIfNotClass($image, Image::class);
+        foreach ($image->getImagick() as $core) {
+            $core->quantizeImage(
+                $this->limit,
+                $core->getImageColorspace(),
+                0,
+                false,
+                false
+            );
+        }
+
+        return $image;
+    }
+}

src/Drivers/Imagick/Traits/CanReduceColors.php

@@ -1,38 +0,0 @@
-<?php
-
-namespace Intervention\Image\Drivers\Imagick\Traits;
-
-use Imagick;
-
-trait CanReduceColors
-{
-    /**
-     * Returns a Imagick from a given image with reduced colors to a given limit.
-     * Reduction is only applied when the given limit is under the given threshold
-     *
-     * @param Imagick $imagick
-     * @param int $limit
-     * @param int $threshold
-     * @return Imagick
-     */
-    private function maybeReduceColors(Imagick $imagick, int $limit, int $threshold = 256): Imagick
-    {
-        if ($limit === 0) {
-            return $imagick;
-        }
-
-        if ($limit > $threshold) {
-            return $imagick;
-        }
-
-        $imagick->quantizeImage(
-            $limit,
-            $imagick->getImageColorspace(),
-            0,
-            false,
-            false
-        );
-
-        return $imagick;
-    }
-}