(PHP4 >= 4.0.2)

ImageTypes --  Return the image types supported by this PHP build


int imagetypes(void);

This function returns a bit-field corresponding to the image formats supported by the version of GD linked into PHP. The following bits are returned, IMG_GIF | IMG_JPG | IMG_PNG | IMG_WBMP. To check for PNG support, for example, do this:

Example 1. ImageTypes

if (ImageTypes() & IMG_PNG) {
    echo "PNG Support is enabled";