Ticket #24380: 24380.3.patch

wp-includes/class-wp-image-editor-gd.php

@@ -383 +383 @@
                         if ( function_exists('imageistruecolor') && ! imageistruecolor( $image ) )
                                 imagetruecolortopalette( $image, false, imagecolorstotal( $image ) );
 
-                        if ( ! $this->make_image( $filename, 'imagepng', array( $image, $filename ) ) )
+                        /*
+                         * Convert quality (1-100) to a valid compression value (0-9)
+                         * -1 = use default zlib compression
+                         *  0 = no compression
+                         *  1 = worst compression
+                         *  9 = best compression
+                         */
+                        $compression_level = floor( $this->quality / 10 );
+
+                        if ( $compression_level > 9 ) {
+                                $compression_level = 9;
+                        } elseif ( -1 != $compression_level && $compression_level < 0 ) {
+                                $compression_level = 0;
+                        }
+                        if ( ! $this->make_image( $filename, 'imagepng', array( $image, $filename, $compression_level ) ) ) {
                                 return new WP_Error( 'image_save_error', __('Image Editor Save Failed') );
+                        }
                 }
                 elseif ( 'image/jpeg' == $mime_type ) {
                         if ( ! $this->make_image( $filename, 'imagejpeg', array( $image, $filename, $this->quality ) ) )

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

@@ -244 +244 @@
                         if ( $quality == 0 ) {
                                 $quality = 1;
                         }
+                } elseif ( 'image/png' == $this->mime_type ) {
+                        /**
+                         * Filter the PNG compression level.
+                         *
+                         * The filter is evaluated under two contexts: 'image_resize', and 'edit_image',
+                         * (when a PNG image is saved to file).
+                         *
+                         * @since 4.0.0
+                         *
+                         * @param int    $quality Compression level, between 1 (worst compression)
+                         *                        and 100 (best but slowest compression).
+                         * @param string $context Context of the filter.
+                         */
+                        $quality = apply_filters( 'png_compression_level', $quality, 'image_resize' );
                 }
 
                 if ( ( $quality >= 1 ) && ( $quality <= 100 ) ){