Ticket #36477: 36477_2.diff

src/wp-includes/class-wp-image-editor-imagick.php

@@ -23 +23 @@
          */
         protected $image;
 
+        /**
+         * Stores the information whether the image is indexed-color encoded
+         *
+         * @since 4.7
+         * @access protected
+         * @var bool
+         */
+        protected $indexed_color_encoded = false;
+        
         public function __destruct() {
                 if ( $this->image instanceof Imagick ) {
                         // we don't need the original in memory anymore
@@ -303 +312 @@
                 );
 
                 /**
+                 * Check image type whether it's using palette (indexed-color encoded).
+                 * Use this property when saving the resized image to preserved its original image type.
+                 * This will reduce occurrences of having a resized image filesize very much larger than the original.
+                 * @since 4.7
+                 */
+                if ( ( is_callable( array( $this->image, 'getImageType' ) ) ) && ( defined( 'imagick::IMGTYPE_PALETTE' ) ) )   {
+                        $image_type     = $this->image->getImageType();
+                        if ( imagick::IMGTYPE_PALETTE === $image_type ) {
+                                $this->indexed_color_encoded    = true;
+                        }
+                }
+                
+                /**
                  * Set the filter value if '$filter_name' name is in our whitelist and the related
                  * Imagick constant is defined or fall back to our default filter.
                  */
@@ -620 +642 @@
                         // Store initial Format
                         $orig_format = $this->image->getImageFormat();
 
+                        // Restore image type when saving the image to preserved original colors and optimized its file size.
+                        if ( ( is_callable( array( $this->image, 'getImageType' ) ) ) && ( true === $this->indexed_color_encoded ) && ( defined( 'imagick::IMGTYPE_PALETTE' ) ) ) {
+                                $this->image->setImageType( imagick::IMGTYPE_PALETTE );
+                        }
+                        
                         $this->image->setImageFormat( strtoupper( $this->get_extension( $mime_type ) ) );
                         $this->make_image( $filename, array( $image, 'writeImage' ), array( $filename ) );