is_gd_image( resource|GdImage|false $image )

Determines whether the value is an acceptable type for GD image functions.

Description

In PHP 8.0, the GD extension uses GdImage objects for its data structures. This function checks if the passed value is either a resource of type gd or a GdImage object instance. Any other type will return false.

Parameters

$image

(resource|GdImage|false) (Required) A value to check the type for.

Return

(bool) True if $image is either a GD image resource or GdImage instance, false otherwise.

Source

File: wp-includes/media.php 

function is_gd_image( $image ) {
	if ( is_resource( $image ) && 'gd' === get_resource_type( $image )
		|| is_object( $image ) && $image instanceof GdImage
	) {
		return true;
	}

	return false;
}

Used By

Used By Description
wp-admin/includes/image-edit.php: image_edit_apply_changes()

Performs group of changes on Editor specified.
wp-admin/includes/image.php: load_image_to_edit()

Load an image resource for editing.
wp-includes/deprecated.php: wp_load_image()

Load an image from a string, if PHP supports it.
wp-includes/class-wp-image-editor-gd.php: WP_Image_Editor_GD::load()

Loads image from $this->file into new GD Resource.
wp-includes/class-wp-image-editor-gd.php: WP_Image_Editor_GD::resize()

Resizes current image.
wp-includes/class-wp-image-editor-gd.php: WP_Image_Editor_GD::_resize()
wp-includes/class-wp-image-editor-gd.php: WP_Image_Editor_GD::crop()

Crops Image.
wp-includes/class-wp-image-editor-gd.php: WP_Image_Editor_GD::rotate()

Rotates current image counter-clockwise by $angle.
wp-includes/class-wp-image-editor-gd.php: WP_Image_Editor_GD::flip()

Flips current image.
wp-includes/media.php: wp_imagecreatetruecolor()

Create new GD image resource with transparency support

Changelog

Version Description
5.6.0 Introduced.

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Licensed under the GNU GPLv2+ License.
https://developer.wordpress.org/reference/functions/is_gd_image