Optimize computing dominant color and transparency for images by combining the two functions

modules/images/dominant-color/class-dominant-color-image-editor-gd.php

@@ -35,11 +35,15 @@ public function get_dominant_color() {
 		$shorted_image = imagecreatetruecolor( 1, 1 );
 		imagecopyresampled( $shorted_image, $this->image, 0, 0, 0, 0, 1, 1, imagesx( $this->image ), imagesy( $this->image ) );
 
-		$hex = dechex( imagecolorat( $shorted_image, 0, 0 ) );
-
-		if ( strlen( $hex ) < 6 ) {
+		$rgb = imagecolorat( $shorted_image, 0, 0 );
+		$r   = ( $rgb >> 16 ) & 0xFF;
+		$g   = ( $rgb >> 8 ) & 0xFF;
+		$b   = $rgb & 0xFF;
+		$hex = get_hex_from_rgb( $r, $g, $b );
+		if ( ! $hex ) {
 			return new WP_Error( 'image_editor_dominant_color_error', __( 'Dominant color detection failed.', 'performance-lab' ) );
 		}
+
 		return $hex;
 	}
 

modules/images/dominant-color/class-dominant-color-image-editor-imagick.php

@@ -35,13 +35,15 @@ public function get_dominant_color() {
 		try {
 			// phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged
 			// The logic here is resize the image to 1x1 pixel, then get the color of that pixel.
-			$this->image->setImageColorspace( Imagick::COLORSPACE_RGB );
-			$this->image->setImageFormat( 'RGB' );
 			$this->image->resizeImage( 1, 1, Imagick::FILTER_LANCZOS, 1 );
 			$pixel = $this->image->getImagePixelColor( 0, 0 );
 			$color = $pixel->getColor();
+			$hex   = get_hex_from_rgb( $color['r'], $color['g'], $color['b'] );
+			if ( ! $hex ) {
+				return new WP_Error( 'image_editor_dominant_color_error', __( 'Dominant color detection failed.', 'performance-lab' ) );
+			}
 
-			return dechex( $color['r'] ) . dechex( $color['g'] ) . dechex( $color['b'] );
+			return $hex;
 		} catch ( Exception $e ) {
 			/* translators: %s is the error message. */
 			return new WP_Error( 'image_editor_dominant_color_error', sprintf( __( 'Dominant color detection failed: %s', 'performance-lab' ), $e->getMessage() ) );
@@ -63,8 +65,32 @@ public function has_transparency() {
 		}
 
 		try {
-			// Check if the image has an alpha channel if true, set to has_transparent to true.
-			return (bool) $this->image->getImageAlphaChannel();
+			/*
+			 * Check if the image has an alpha channel if false, then it can't have transparency so return early.
+			 *
+			 * Note that Imagick::getImageAlphaChannel() is only available if Imagick
+			 * has been compiled against ImageMagick version 6.4.0 or newer.
+			 */
+			if ( is_callable( array( $this->image, 'getImageAlphaChannel' ) ) ) {
+				if ( ! $this->image->getImageAlphaChannel() ) {
+					return false;
+				}
+			}
+
+			// Walk through the pixels and look transparent pixels.
+			$w = $this->image->getImageWidth();
+			$h = $this->image->getImageHeight();
+			for ( $x = 0; $x < $w; $x++ ) {
+				for ( $y = 0; $y < $h; $y++ ) {
+					$pixel = $this->image->getImagePixelColor( $x, $y );
+					$color = $pixel->getColor();
+					if ( $color['a'] > 0 ) {
+						return true;
+					}
+				}
+			}
+			return false;
+
 		} catch ( Exception $e ) {
 			/* translators: %s is the error message */
 			return new WP_Error( 'image_editor_has_transparency_error', sprintf( __( 'Transparency detection failed: %s', 'performance-lab' ), $e->getMessage() ) );

modules/images/dominant-color/load.php

@@ -18,18 +18,15 @@
  * @return array $metadata The attachment metadata.
  */
 function dominant_color_metadata( $metadata, $attachment_id ) {
-	if ( ! wp_attachment_is_image( $attachment_id ) ) {
-		return $metadata;
-	}
-
-	$dominant_color = dominant_color_get_dominant_color( $attachment_id );
-	if ( ! is_wp_error( $dominant_color ) && ! empty( $dominant_color ) ) {
-		$metadata['dominant_color'] = $dominant_color;
-	}
+	$dominant_color_data = _dominant_color_get_dominant_color_data( $attachment_id );
+	if ( ! is_wp_error( $dominant_color_data ) ) {
+		if ( isset( $dominant_color_data['dominant_color'] ) ) {
+			$metadata['dominant_color'] = $dominant_color_data['dominant_color'];
+		}
 
-	$has_transparency = dominant_color_has_transparency( $attachment_id );
-	if ( ! is_wp_error( $has_transparency ) ) {
-		$metadata['has_transparency'] = $has_transparency;
+		if ( isset( $dominant_color_data['has_transparency'] ) ) {
+			$metadata['has_transparency'] = $dominant_color_data['has_transparency'];
+		}
 	}
 
 	return $metadata;
@@ -255,43 +252,15 @@ function dominant_color_set_image_editors() {
  * Computes the dominant color of the given attachment image.
  *
  * @since 1.2.0
+ * @access private
  *
  * @param int $attachment_id The attachment ID.
- * @return string|WP_Error The dominant color of the image, or WP_Error on error.
+ * @return array|WP_Error Array with the dominant color and has transparency values or WP_Error on error.
  */
-function dominant_color_get_dominant_color( $attachment_id ) {
-	$file = wp_get_attachment_file_path( $attachment_id );
-	if ( ! $file ) {
-		$file = get_attached_file( $attachment_id );
-	}
-	add_filter( 'wp_image_editors', 'dominant_color_set_image_editors' );
-	$editor = wp_get_image_editor( $file );
-	remove_filter( 'wp_image_editors', 'dominant_color_set_image_editors' );
-
-	if ( is_wp_error( $editor ) ) {
-		return $editor;
-	}
-	if ( ! method_exists( $editor, 'get_dominant_color' ) ) {
-		return new WP_Error( 'unable_to_find_method', __( 'Unable to find get_dominant_color method', 'performance-lab' ) );
-	}
-
-	$dominant_color = $editor->get_dominant_color();
-	if ( is_wp_error( $dominant_color ) ) {
-		return $dominant_color;
+function _dominant_color_get_dominant_color_data( $attachment_id ) {
+	if ( ! wp_attachment_is_image( $attachment_id ) ) {
+		return new WP_Error( 'no_image_found', __( 'Unable to load image.', 'performance-lab' ) );
 	}
-
-	return $dominant_color;
-}
-
-/**
- * Computes whether the given attachment image has transparency.
- *
- * @since 1.2.0
- *
- * @param int $attachment_id The attachment ID.
- * @return bool|WP_Error True if the color has transparency or WP_Error on error.
- */
-function dominant_color_has_transparency( $attachment_id ) {
 	$file = wp_get_attachment_file_path( $attachment_id );
 	if ( ! $file ) {
 		$file = get_attached_file( $attachment_id );
@@ -303,15 +272,27 @@ function dominant_color_has_transparency( $attachment_id ) {
 	if ( is_wp_error( $editor ) ) {
 		return $editor;
 	}
+
 	if ( ! method_exists( $editor, 'has_transparency' ) ) {
 		return new WP_Error( 'unable_to_find_method', __( 'Unable to find has_transparency method', 'performance-lab' ) );
 	}
 	$has_transparency = $editor->has_transparency();
 	if ( is_wp_error( $has_transparency ) ) {
 		return $has_transparency;
 	}
+	$dominant_color_data['has_transparency'] = $has_transparency;
+
+	if ( ! method_exists( $editor, 'get_dominant_color' ) ) {
+		return new WP_Error( 'unable_to_find_method', __( 'Unable to find get_dominant_color method', 'performance-lab' ) );
+	}
+
+	$dominant_color = $editor->get_dominant_color();
+	if ( is_wp_error( $dominant_color ) ) {
+		return $dominant_color;
+	}
+	$dominant_color_data['dominant_color'] = $dominant_color;
 
-	return $has_transparency;
+	return $dominant_color_data;
 }
 
 /**
@@ -339,3 +320,69 @@ function wp_get_attachment_file_path( $attachment_id, $size = 'medium' ) {
 
 	return $filepath;
 }
+
+/**
+ * Gets the dominant color for an image attachment.
+ *
+ * @since n.e.x.t
+ *
+ * @param int $attachment_id Attachment ID for image.
+ * @return string|null Hex value of dominant color or null if not set.
+ */
+function dominant_color_get_dominant_color( $attachment_id ) {
+	if ( ! wp_attachment_is_image( $attachment_id ) ) {
+		return null;
+	}
+	$image_meta = wp_get_attachment_metadata( $attachment_id );
+	if ( ! is_array( $image_meta ) ) {
+		return null;
+	}
+
+	if ( ! isset( $image_meta['dominant_color'] ) ) {
+		return null;
+	}
+
+	return $image_meta['dominant_color'];
+}
+
+/**
+ * Returns whether an image attachment has transparency.
+ *
+ * @since n.e.x.t
+ *
+ * @param int $attachment_id Attachment ID for image.
+ * @return bool|null Whether the image has transparency, or null if not set.
+ */
+function dominant_color_has_transparency( $attachment_id ) {
+	$image_meta = wp_get_attachment_metadata( $attachment_id );
+	if ( ! is_array( $image_meta ) ) {
+		return null;
+	}
+
+	if ( ! isset( $image_meta['has_transparency'] ) ) {
+		return null;
+	}
+
+	return $image_meta['has_transparency'];
+}
+
+
+/**
+ * Get Hex color from RGB.
+ *
+ * @since n.e.x.t
+ *
+ * @param int $red Red 0-255.
+ * @param int $green Green 0-255.
+ * @param int $blue Blue 0-255.
+ *
+ * @return string|null Hex color or null if error.
+ */
+function get_hex_from_rgb( $red, $green, $blue ) {
+	$range = range( 0, 255 );
+	if ( ! in_array( $red, $range, true ) || ! in_array( $green, $range, true ) || ! in_array( $blue, $range, true ) ) {
+		return null;
+	}
+
+	return sprintf( '%02x%02x%02x', $red, $green, $blue );
+}

tests/modules/images/dominant-color/dominant-color-image-editor-gd-test.php

@@ -20,36 +20,60 @@ static function () {
 			100
 		);
 	}
+
 	/**
 	 * Test if the function returns the correct color.
 	 *
 	 * @dataProvider provider_get_dominant_color
 	 *
-	 * @covers Dominant_Color_Image_Editor_GD::get_dominant_color
+	 * @covers       Dominant_Color_Image_Editor_GD::get_dominant_color
 	 */
-	public function test_get_dominant_color( $image_path, $expected_color, $is_wp_error ) {
+	public function test_get_dominant_color( $image_path, $expected_color, $expected_transparency ) {
 
 		$attachment_id = $this->factory->attachment->create_upload_object( $image_path );
 		wp_maybe_generate_attachment_metadata( get_post( $attachment_id ) );
-		$color = dominant_color_get_dominant_color( $attachment_id );
-		if ( ! $is_wp_error ) {
-			$this->assertContains( $color, $expected_color );
-		} else {
-			$this->assertInstanceOf( 'WP_Error', $color );
-		}
+
+		$dominant_color_data = _dominant_color_get_dominant_color_data( $attachment_id );
+
+		$this->assertContains( $dominant_color_data['dominant_color'], $expected_color );
+		$this->assertSame( $dominant_color_data['has_transparency'], $expected_transparency );
 	}
 
 	/**
 	 * Test if the function returns the correct color.
 	 *
-	 * @dataProvider provider_get_has_transparency
+	 * @dataProvider provider_get_dominant_color_invalid_images
 	 *
-	 * @covers ::dominant_color_has_transparency
+	 * @group ms-excluded
+	 *
+	 * @covers       Dominant_Color_Image_Editor_GD::get_dominant_color
 	 */
-	public function test_dominant_color_get_has_transparency( $image_path, $expected_tranasparency ) {
+	public function test_get_dominant_color_invalid( $image_path, $expected_color, $expected_transparency ) {
+
 		$attachment_id = $this->factory->attachment->create_upload_object( $image_path );
 		wp_maybe_generate_attachment_metadata( get_post( $attachment_id ) );
-		$this->assertEquals( $expected_tranasparency, dominant_color_has_transparency( $attachment_id ) );
+
+		$dominant_color_data = _dominant_color_get_dominant_color_data( $attachment_id );
+
+		$this->assertWPError( $dominant_color_data );
+		$this->assertStringContainsString( 'image_no_editor', $dominant_color_data->get_error_code() );
 	}
 
+	/**
+	 * Test if the function returns the correct color.
+	 *
+	 * @dataProvider provider_get_dominant_color_none_images
+	 *
+	 * @covers       Dominant_Color_Image_Editor_GD::get_dominant_color
+	 */
+	public function test_get_dominant_color_none_images( $image_path ) {
+
+		$attachment_id = $this->factory->attachment->create_upload_object( $image_path );
+		wp_maybe_generate_attachment_metadata( get_post( $attachment_id ) );
+
+		$dominant_color_data = _dominant_color_get_dominant_color_data( $attachment_id );
+
+		$this->assertWPError( $dominant_color_data );
+		$this->assertStringContainsString( 'no_image_found', $dominant_color_data->get_error_code() );
+	}
 }

tests/modules/images/dominant-color/dominant-color-image-editor-imageick-test.php

@@ -28,30 +28,57 @@ static function () {
 	 *
 	 * @dataProvider provider_get_dominant_color
 	 *
-	 * @covers Dominant_Color_Image_Editor_GD::get_dominant_color
+	 * @covers       Dominant_Color_Image_Editor_GD::get_dominant_color
 	 */
-	public function test_get_dominant_color( $image_path, $expected_color, $is_wp_error ) {
+	public function test_get_dominant_color( $image_path, $expected_color, $expected_transparency ) {
 
 		$attachment_id = $this->factory->attachment->create_upload_object( $image_path );
 		wp_maybe_generate_attachment_metadata( get_post( $attachment_id ) );
-		$color = dominant_color_get_dominant_color( $attachment_id );
-		if ( ! $is_wp_error ) {
-			$this->assertContains( $color, $expected_color );
-		} else {
-			$this->assertInstanceOf( 'WP_Error', $color );
+
+		$dominant_color_data = _dominant_color_get_dominant_color_data( $attachment_id );
+
+		$this->assertContains( $dominant_color_data['dominant_color'], $expected_color );
+		if ( strpos( $image_path, '.gif' ) ) {
+			$expected_transparency = true; // all gif have alpha.
 		}
+		$this->assertSame( $dominant_color_data['has_transparency'], $expected_transparency );
+	}
+
+	/**
+	 * Test if the function returns the correct color.
+	 *
+	 * @dataProvider provider_get_dominant_color_invalid_images
+	 *
+	 * @group ms-excluded
+	 *
+	 * @covers       Dominant_Color_Image_Editor_GD::get_dominant_color
+	 */
+	public function test_get_dominant_color_invalid( $image_path, $expected_color, $expected_transparency ) {
+
+		$attachment_id = $this->factory->attachment->create_upload_object( $image_path );
+		wp_maybe_generate_attachment_metadata( get_post( $attachment_id ) );
+
+		$dominant_color_data = _dominant_color_get_dominant_color_data( $attachment_id );
+
+		$this->assertContains( $dominant_color_data['dominant_color'], $expected_color );
+		$this->assertSame( $dominant_color_data['has_transparency'], $expected_transparency );
 	}
 
 	/**
 	 * Test if the function returns the correct color.
 	 *
-	 * @dataProvider provider_get_has_transparency
+	 * @dataProvider provider_get_dominant_color_none_images
 	 *
-	 * @covers ::dominant_color_has_transparency
+	 * @covers       Dominant_Color_Image_Editor_GD::get_dominant_color
 	 */
-	public function test_dominant_color_get_has_transparency( $image_path, $expected_tranasparency ) {
+	public function test_get_dominant_color_none_images( $image_path ) {
+
 		$attachment_id = $this->factory->attachment->create_upload_object( $image_path );
 		wp_maybe_generate_attachment_metadata( get_post( $attachment_id ) );
-		$this->assertEquals( $expected_tranasparency, dominant_color_has_transparency( $attachment_id ) );
+
+		$dominant_color_data = _dominant_color_get_dominant_color_data( $attachment_id );
+
+		$this->assertWPError( $dominant_color_data );
+		$this->assertStringContainsString( 'no_image_found', $dominant_color_data->get_error_code() );
 	}
 }