Change WP Image editor quality for mime types

modules/images/webp-uploads/load.php

@@ -742,3 +742,30 @@ function webp_uploads_get_image_sizes_additional_mime_type_support() {
 
 	return $allowed_sizes;
 }
+
+/**
+ * Updates the quality of WebP image sizes generated by WordPress to 82.
+ *
+ * Prior to WordPress 6.1, the MIME type was not correctly provided to this filter, so for those versions this function
+ * simply returns 82 universally (since all other MIME types already use 82 anyway).
+ *
+ * @since n.e.x.t
+ *
+ * @global string $wp_version The WordPress version string.
+ *
+ * @param int    $quality   Quality level between 1 (low) and 100 (high).
+ * @param string $mime_type Image mime type.
+ * @return int The updated quality for mime types.
+ */
+function webp_uploads_modify_webp_quality( $quality, $mime_type ) {
+	global $wp_version;
+
+	// Below WP 6.1 or for WebP images, always return 82 (other MIME types were already using 82 by default anyway).
+	if ( version_compare( $wp_version, '6.1', '<' ) || 'image/webp' === $mime_type ) {
+		return 82;
+	}
+
+	// Return default quality for non-WebP images in WP 6.1+.
+	return $quality;
+}
+add_filter( 'wp_editor_set_quality', 'webp_uploads_modify_webp_quality', 10, 2 );

tests/modules/images/webp-uploads/load-tests.php

@@ -775,6 +775,7 @@ public function it_should_create_webp_for_full_size_which_is_smaller_in_webp_for
 		$this->opt_in_to_jpeg_and_webp();
 
 		add_filter( 'webp_uploads_discard_larger_generated_images', '__return_true' );
+		add_filter( 'wp_editor_set_quality', array( $this, 'return_webp_image_quality' ), PHP_INT_MAX, 2 );
 
 		// Look for an image that contains only full size mime type images.
 		$attachment_id = self::factory()->attachment->create_upload_object( TESTS_PLUGIN_DIR . '/tests/testdata/modules/images/leafs.jpg' );
@@ -789,6 +790,8 @@ public function it_should_create_webp_for_full_size_which_is_smaller_in_webp_for
 			$this->assertImageNotHasSizeSource( $attachment_id, $size, 'image/webp' );
 		}
 		$this->assertNotSame( $tag, webp_uploads_img_tag_update_mime_type( $tag, 'the_content', $attachment_id ) );
+
+		remove_filter( 'wp_editor_set_quality', array( $this, 'return_webp_image_quality' ), PHP_INT_MAX );
 	}
 
 	/**
@@ -801,6 +804,7 @@ public function it_should_create_webp_for_some_sizes_which_are_smaller_in_webp_f
 		$this->opt_in_to_jpeg_and_webp();
 
 		add_filter( 'webp_uploads_discard_larger_generated_images', '__return_true' );
+		add_filter( 'wp_editor_set_quality', array( $this, 'return_webp_image_quality' ), PHP_INT_MAX, 2 );
 
 		// Look for an image that contains all of the additional mime type images.
 		$attachment_id = self::factory()->attachment->create_upload_object( TESTS_PLUGIN_DIR . '/tests/testdata/modules/images/balloons.webp' );
@@ -821,6 +825,8 @@ public function it_should_create_webp_for_some_sizes_which_are_smaller_in_webp_f
 
 		$this->assertNotSame( $tag, $updated_tag );
 		$this->assertSame( $expected_tag, $updated_tag );
+
+		remove_filter( 'wp_editor_set_quality', array( $this, 'return_webp_image_quality' ), PHP_INT_MAX );
 	}
 
 	/**
@@ -918,11 +924,66 @@ public function it_should_create_mime_types_for_allowed_sizes_only_via_global_va
 		$this->assertImageNotHasSizeSource( $attachment_id, 'not_allowed_size_200x150', 'image/webp' );
 	}
 
+	/**
+	 * Test image quality for image conversion.
+	 *
+	 * @test
+	 */
+	public function it_should_set_quality_with_image_conversion() {
+		$editor = wp_get_image_editor( TESTS_PLUGIN_DIR . '/tests/testdata/modules/images/dice.png', array( 'mime_type' => 'image/png' ) );
+
+		// Quality setting for the source image. For PNG the fallback default of 82 is used.
+		$this->assertSame( 82, $editor->get_quality(), 'Default quality setting for PNG is 82.' );
+
+		// Temporary file.
+		$file = wp_tempnam();
+
+		// A PNG image will be converted to WebP whose quality should be 82 universally.
+		$editor->save( $file, 'image/webp' );
+		$this->assertSame( 82, $editor->get_quality(), 'Output image format is WebP. Quality setting for it should be 82 universally.' );
+
+		$editor = wp_get_image_editor( TESTS_PLUGIN_DIR . '/tests/testdata/modules/images/leafs.jpg' );
+
+		// Quality setting for the source image. For JPG the fallback default of 82 is used.
+		$this->assertSame( 82, $editor->get_quality(), 'Default quality setting for JPG is 82.' );
+
+		// A JPG image will be converted to WebP whose quality should be 82 universally.
+		$editor->save( $file, 'image/webp' );
+		$this->assertSame( 82, $editor->get_quality(), 'Output image format is WebP. Quality setting for it should be 82 universally.' );
+
+		// Delete the temporary file.
+		unlink( $file );
+	}
+
+	/**
+	 * Test webp_uploads_modify_webp_quality function for image quality.
+	 *
+	 * @covers ::webp_uploads_modify_webp_quality()
+	 *
+	 * @test
+	 */
+	public function it_should_return_correct_quality_for_mime_types() {
+		$this->assertSame( 82, webp_uploads_modify_webp_quality( 90, 'image/webp' ), 'WebP image quality should always be 82.' );
+		$this->assertSame( 82, webp_uploads_modify_webp_quality( 82, 'image/webp' ), 'WebP image quality should always be 82.' );
+		$this->assertSame( 80, webp_uploads_modify_webp_quality( 80, 'image/jpeg' ), 'JPEG image quality should return default quality provided from WP filter wp_editor_set_quality.' );
+		$this->assertNotSame( 50, webp_uploads_modify_webp_quality( 40, 'image/jpeg' ), 'JPEG image quality should return default quality provided from WP filter wp_editor_set_quality.' );
+	}
+
 	/**
 	 * Runs (empty) hooks to satisfy webp_uploads_in_frontend_body() conditions.
 	 */
 	private function mock_frontend_body_hooks() {
 		remove_all_actions( 'template_redirect' );
 		do_action( 'template_redirect' );
 	}
+
+	/**
+	 * Return WebP image quality 86 for testing.
+	 */
+	public function return_webp_image_quality( $quality, $mime_type ) {
+		if ( 'image/webp' === $mime_type ) {
+			return 86;
+		}
+		return $quality;
+	}
 }

tests/utils/TestCase/DominantColorTestCase.php

@@ -24,7 +24,7 @@ public function provider_get_dominant_color() {
 			),
 			'green_jpg'     => array(
 				'image_path'            => TESTS_PLUGIN_DIR . '/tests/testdata/modules/images/dominant-color/green.jpg',
-				'expected_color'        => array( '00ff00', '00ff01' ),
+				'expected_color'        => array( '00ff00', '00ff01', '02ff01' ),
 				'expected_transparency' => false,
 			),
 			'white_jpg'     => array(