(PHP 4 >= 4.0.6, PHP 5, PHP 7) Get the index of the specified color + alpha

(PHP 4, PHP 5, PHP 7) Create a new image from file or URL

(PHP 4, PHP 5, PHP 7) Get the colors for an index

(PHP 5 >= 5.5.0, PHP 7) Flips an image using a given mode

(PHP 4 >= 4.0.1, PHP 5, PHP 7) Get the index of the color which has the hue, white and blackness

(PHP 4 >= 4.3.0, PHP 5, PHP 7) Retrieve information about the currently installed GD library

(PHP 4, PHP 5, PHP 7) Create a new image from file or URL

(PHP 4 >= 4.0.5, PHP 5, PHP 7) Output image to browser or file

(PHP 4, PHP 5, PHP 7) Get the index of the closest color to the specified color

(PHP 4, PHP 5, PHP 7) Copy and resize part of an image