Predefined Constants
The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.
- GD_VERSION (string)
 - The GD version PHP was compiled against. (Available as of PHP 5.2.4)
 - GD_MAJOR_VERSION (integer)
 - The GD major version PHP was compiled against. (Available as of PHP 5.2.4)
 - GD_MINOR_VERSION (integer)
 - The GD minor version PHP was compiled against. (Available as of PHP 5.2.4)
 - GD_RELEASE_VERSION (integer)
 - The GD release version PHP was compiled against. (Available as of PHP 5.2.4)
 - GD_EXTRA_VERSION (string)
 - The GD "extra" version (beta/rc..) PHP was compiled against. (Available as of PHP 5.2.4)
 - GD_BUNDLED (integer)
 - When the bundled version of GD is used this is 1 otherwise its set to 0.
 - IMG_GIF (integer)
 - Used as a return value by imagetypes()
 - IMG_JPG (integer)
 - Used as a return value by imagetypes()
 - IMG_JPEG (integer)
 - 
    
     Used as a return value by imagetypes()
    
    
Note:
This constant has the same value as IMG_JPG
 - IMG_PNG (integer)
 - Used as a return value by imagetypes()
 - IMG_WBMP (integer)
 - Used as a return value by imagetypes()
 - IMG_XPM (integer)
 - Used as a return value by imagetypes()
 - IMG_COLOR_TILED (integer)
 - Special color option which can be used in stead of color allocated with imagecolorallocate() or imagecolorallocatealpha()
 - IMG_COLOR_STYLED (integer)
 - Special color option which can be used in stead of color allocated with imagecolorallocate() or imagecolorallocatealpha()
 - IMG_COLOR_BRUSHED (integer)
 - Special color option which can be used in stead of color allocated with imagecolorallocate() or imagecolorallocatealpha()
 - IMG_COLOR_STYLEDBRUSHED (integer)
 - Special color option which can be used in stead of color allocated with imagecolorallocate() or imagecolorallocatealpha()
 - IMG_COLOR_TRANSPARENT (integer)
 - Special color option which can be used in stead of color allocated with imagecolorallocate() or imagecolorallocatealpha()
 - IMG_ARC_ROUNDED (integer)
 - 
    
     A style constant used by the imagefilledarc() function.
    
    
Note:
This constant has the same value as IMG_ARC_PIE
 - IMG_ARC_PIE (integer)
 - A style constant used by the imagefilledarc() function.
 - IMG_ARC_CHORD (integer)
 - A style constant used by the imagefilledarc() function.
 - IMG_ARC_NOFILL (integer)
 - A style constant used by the imagefilledarc() function.
 - IMG_ARC_EDGED (integer)
 - A style constant used by the imagefilledarc() function.
 - IMG_GD2_RAW (integer)
 - A type constant used by the imagegd2() function.
 - IMG_GD2_COMPRESSED (integer)
 - A type constant used by the imagegd2() function.
 - IMG_EFFECT_REPLACE (integer)
 - Alpha blending effect used by the imagelayereffect() function.
 - IMG_EFFECT_ALPHABLEND (integer)
 - Alpha blending effect used by the imagelayereffect() function.
 - IMG_EFFECT_NORMAL (integer)
 - Alpha blending effect used by the imagelayereffect() function.
 - IMG_EFFECT_OVERLAY (integer)
 - Alpha blending effect used by the imagelayereffect() function.
 - IMG_FILTER_NEGATE (integer)
 - Special GD filter used by the imagefilter() function.
 - IMG_FILTER_GRAYSCALE (integer)
 - Special GD filter used by the imagefilter() function.
 - IMG_FILTER_BRIGHTNESS (integer)
 - Special GD filter used by the imagefilter() function.
 - IMG_FILTER_CONTRAST (integer)
 - Special GD filter used by the imagefilter() function.
 - IMG_FILTER_COLORIZE (integer)
 - Special GD filter used by the imagefilter() function.
 - IMG_FILTER_EDGEDETECT (integer)
 - Special GD filter used by the imagefilter() function.
 - IMG_FILTER_GAUSSIAN_BLUR (integer)
 - Special GD filter used by the imagefilter() function.
 - IMG_FILTER_SELECTIVE_BLUR (integer)
 - Special GD filter used by the imagefilter() function.
 - IMG_FILTER_EMBOSS (integer)
 - Special GD filter used by the imagefilter() function.
 - IMG_FILTER_MEAN_REMOVAL (integer)
 - Special GD filter used by the imagefilter() function.
 - IMG_FILTER_SMOOTH (integer)
 - Special GD filter used by the imagefilter() function.
 - IMG_FILTER_PIXELATE (integer)
 - Special GD filter used by the imagefilter() function. (Available as of PHP 5.3.0)
 - IMAGETYPE_GIF (integer)
 - Image type constant used by the image_type_to_mime_type() and image_type_to_extension() functions.
 - IMAGETYPE_JPEG (integer)
 - Image type constant used by the image_type_to_mime_type() and image_type_to_extension() functions.
 - IMAGETYPE_JPEG2000 (integer)
 - Image type constant used by the image_type_to_mime_type() and image_type_to_extension() functions.
 - IMAGETYPE_PNG (integer)
 - Image type constant used by the image_type_to_mime_type() and image_type_to_extension() functions.
 - IMAGETYPE_SWF (integer)
 - Image type constant used by the image_type_to_mime_type() and image_type_to_extension() functions.
 - IMAGETYPE_PSD (integer)
 - Image type constant used by the image_type_to_mime_type() and image_type_to_extension() functions.
 - IMAGETYPE_BMP (integer)
 - Image type constant used by the image_type_to_mime_type() and image_type_to_extension() functions.
 - IMAGETYPE_WBMP (integer)
 - Image type constant used by the image_type_to_mime_type() and image_type_to_extension() functions.
 - IMAGETYPE_XBM (integer)
 - Image type constant used by the image_type_to_mime_type() and image_type_to_extension() functions.
 - IMAGETYPE_TIFF_II (integer)
 - Image type constant used by the image_type_to_mime_type() and image_type_to_extension() functions.
 - IMAGETYPE_TIFF_MM (integer)
 - Image type constant used by the image_type_to_mime_type() and image_type_to_extension() functions.
 - IMAGETYPE_IFF (integer)
 - Image type constant used by the image_type_to_mime_type() and image_type_to_extension() functions.
 - IMAGETYPE_JB2 (integer)
 - Image type constant used by the image_type_to_mime_type() and image_type_to_extension() functions.
 - IMAGETYPE_JPC (integer)
 - Image type constant used by the image_type_to_mime_type() and image_type_to_extension() functions.
 - IMAGETYPE_JP2 (integer)
 - Image type constant used by the image_type_to_mime_type() and image_type_to_extension() functions.
 - IMAGETYPE_JPX (integer)
 - Image type constant used by the image_type_to_mime_type() and image_type_to_extension() functions.
 - IMAGETYPE_SWC (integer)
 - Image type constant used by the image_type_to_mime_type() and image_type_to_extension() functions.
 - IMAGETYPE_ICO (integer)
 - Image type constant used by the image_type_to_mime_type() and image_type_to_extension() functions. (Available as of PHP 5.3.0)
 - PNG_NO_FILTER (integer)
 - A special PNG filter, used by the imagepng() function.
 - PNG_FILTER_NONE (integer)
 - A special PNG filter, used by the imagepng() function.
 - PNG_FILTER_SUB (integer)
 - A special PNG filter, used by the imagepng() function.
 - PNG_FILTER_UP (integer)
 - A special PNG filter, used by the imagepng() function.
 - PNG_FILTER_AVG (integer)
 - A special PNG filter, used by the imagepng() function.
 - PNG_FILTER_PAETH (integer)
 - A special PNG filter, used by the imagepng() function.
 - PNG_ALL_FILTERS (integer)
 - A special PNG filter, used by the imagepng() function.