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Image toolkits

  1. drupal
    1. 6 drupal/includes/
    2. 7 drupal/includes/

Functions for image file manipulations.

Drupal's image toolkits provide an abstraction layer for common image file manipulations like scaling, cropping, and rotating. The abstraction frees module authors from the need to support multiple image libraries, and it allows site administrators to choose the library that's best for them.

PHP includes the GD library by default so a GD toolkit is installed with Drupal. Other toolkits like ImageMagick are available from contrib modules. GD works well for small images, but using it with larger files may cause PHP to run out of memory. In contrast the ImageMagick library does not suffer from this problem, but it requires the ISP to have installed additional software.

Image toolkits are discovered based on the associated module's hook_image_toolkits. Additionally the image toolkit include file must be identified in the files array in the file. The toolkit must then be enabled using the admin/config/media/image-toolkit form.

Only one toolkit may be selected at a time. If a module author wishes to call a specific toolkit they can check that it is installed by calling image_get_available_toolkits(), and then calling its functions directly.

Functions & methods

image_cropCrop an image to the rectangle specified by the given rectangle.
image_desaturateConvert an image to grayscale.
image_gd_check_settingsVerify GD2 settings (that the right version is actually installed).
image_gd_create_tmpCreate a truecolor image preserving transparency from a provided image.
image_gd_cropCrop an image using the GD toolkit.
image_gd_desaturateConvert an image resource to grayscale.
image_gd_get_infoGet details about an image.
image_gd_loadGD helper function to create an image resource from a file.
image_gd_resizeScale an image to the specified size using GD.
image_gd_rotateRotate an image the given number of degrees.
image_gd_saveGD helper to write an image resource to a destination file.
image_gd_settingsRetrieve settings for the GD2 toolkit.
image_gd_settings_validateValidate the submitted GD settings.
image_get_available_toolkitsReturn a list of available toolkits.
image_get_infoGet details about an image.
image_get_toolkitRetrieve the name of the currently used toolkit.
image_loadLoad an image file and return an image object.
image_resizeResize an image to the given dimensions (ignoring aspect ratio).
image_rotateRotate an image by the given number of degrees.
image_saveClose the image and save the changes to a file.
image_scaleScales an image to the given width and height while maintaining aspect ratio.
image_scale_and_cropScales an image to the exact width and height given.
image_toolkit_invokeInvokes the given method using the currently selected toolkit.


drupal/includes/, line 8
API for manipulating images.