1 image.gd.inc image_gd_desaturate(stdClass $image)

Convert an image resource to grayscale.

Note that transparent GIFs loose transparency when desaturated.


$image: An image object. The $image->resource value will be modified by this call.

Return value

TRUE or FALSE, based on success.:

See also


Related topics


core/modules/system/image.gd.inc, line 223
GD2 toolkit for image manipulation within Backdrop.


function image_gd_desaturate(stdClass $image) {
  // PHP installations using non-bundled GD do not have imagefilter.
  if (!function_exists('imagefilter')) {
    watchdog('image', 'The image %file could not be desaturated because the imagefilter() function is not available in this PHP installation.', array('%file' => $image->source));
    return FALSE;

  return imagefilter($image->resource, IMG_FILTER_GRAYSCALE);