is_gd_image( resource|GdImage|false $image ): bool
- Since
- 5.6.0
- Source
wp-includes/media.php:4258
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 GdImage object instance or a resource of type gd. Any other type will return false.
Compatibility
- WordPress
- since 5.6.0
- PHP
- 7.4–8.6-dev
- 6.7.7
- 6.8.8
- 6.9.7
- 7.0.4
- 7.1.0
Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.
Parameters
$imageresource|GdImage|false- A value to check the type for.
Return value
bool- True if
$imageis either a GD image resource or a GdImage instance, false otherwise.
Performance profile
How much work a call to is_gd_image() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.
- Cost class
- Trivial
- Scaling
- Constant
- Instructions
- 4–11
- Plugin surface
- None
- Called by
- 13
Touches nothing outside its own arguments.
No loop in the body: the same number of instructions runs whatever you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 12.
Nothing here hands control to plugin code.
13 places in core call this, so the cost is paid more often than your own code shows.
What one call costs · 2 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost is_gd_image() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
| always | 4–6 | none |
!($image instanceof) && is_resource($image) | 11 | get_resource_type() |
Across PHP versions
Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 12 instructions, 4–11 executed per call, 3 branches. The work does not change between versions.
An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.
Used by · 13
- WP_Image_Editor_GD::_resize()
- WP_Image_Editor_GD::crop()Crops Image.
- WP_Image_Editor_GD::flip()Flips current image.
- WP_Image_Editor_GD::load()Loads image from $this->file into new GD Resource.
- WP_Image_Editor_GD::resize()Resizes current image.
- WP_Image_Editor_GD::rotate()Rotates current image counter-clockwise by $angle.
- _crop_image_resource()Crops an image resource. Internal use only.
- _flip_image_resource()Flips an image resource. Internal use only.
- _rotate_image_resource()Returns an image resource. Internal use only.
- image_edit_apply_changes()Performs group of changes on Editor specified.
- load_image_to_edit()Loads an image resource for editing.
- wp_imagecreatetruecolor()Creates a new GD image resource with transparency support.
Show all 13
- wp_load_image()Load an image from a string, if PHP supports it.
Source code
function is_gd_image( $image ) { if ( $image instanceof GdImage // @phpstan-ignore class.notFound (Only available with PHP8+.) || is_resource( $image ) && 'gd' === get_resource_type( $image ) ) { return true; } return false;}Changelog
Introduced in 5.6.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
About this page
- Parsed data
- Generated from the wordpress-develop 7.1.0 tag, from
src/wp-includes/media.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it. - Corrections
- Something wrong on this page? Report it and it gets fixed in the next regeneration.