下列常量由此扩展定义,且仅在此扩展编译入 PHP 或在运行时动态载入时可用。
GD_VERSION
    (string)
   
   GD_MAJOR_VERSION
    (integer)
   
   GD_MINOR_VERSION
    (integer)
   
   GD_RELEASE_VERSION
    (integer)
   
   GD_EXTRA_VERSION
    (string)
   
   GD_BUNDLED
    (integer)
   
   IMG_GIF 
    (integer)
   
   IMG_JPG 
    (integer)
   
   IMG_JPEG 
     (integer)
   
   Note:
This constant has the same value as
IMG_JPG
IMG_PNG 
    (integer)
   
   IMG_WBMP 
    (integer)
   
   IMG_XPM 
    (integer)
   
   IMG_COLOR_TILED 
    (integer)
   
   IMG_COLOR_STYLED 
    (integer)
   
   IMG_COLOR_BRUSHED 
    (integer)
   
   IMG_COLOR_STYLEDBRUSHED 
    (integer)
   
   IMG_COLOR_TRANSPARENT 
    (integer)
   
   IMG_ARC_ROUNDED 
    (integer)
   
   Note:
This constant has the same value as
IMG_ARC_PIE
IMG_ARC_PIE 
    (integer)
   
   IMG_ARC_CHORD 
    (integer)
   
   IMG_ARC_NOFILL 
    (integer)
   
   IMG_ARC_EDGED 
    (integer)
   
   IMG_GD2_RAW 
    (integer)
   
   IMG_GD2_COMPRESSED 
    (integer)
   
   IMG_EFFECT_REPLACE 
    (integer)
   
   IMG_EFFECT_ALPHABLEND 
    (integer)
   
   IMG_EFFECT_NORMAL 
    (integer)
   
   IMG_EFFECT_OVERLAY 
    (integer)
   
   IMG_FILTER_NEGATE 
    (integer)
   
   IMG_FILTER_GRAYSCALE 
    (integer)
   
   IMG_FILTER_BRIGHTNESS 
    (integer)
   
   IMG_FILTER_CONTRAST 
    (integer)
   
   IMG_FILTER_COLORIZE 
    (integer)
   
   IMG_FILTER_EDGEDETECT 
    (integer)
   
   IMG_FILTER_GAUSSIAN_BLUR 
    (integer)
   
   IMG_FILTER_SELECTIVE_BLUR 
    (integer)
   
   IMG_FILTER_EMBOSS 
    (integer)
   
   IMG_FILTER_MEAN_REMOVAL 
    (integer)
   
   IMG_FILTER_SMOOTH 
    (integer)
   
   IMG_FILTER_PIXELATE 
    (integer)
   
   IMAGETYPE_GIF 
    (integer)
   
   IMAGETYPE_JPEG 
    (integer)
   
   IMAGETYPE_JPEG2000 
    (integer)
   
   IMAGETYPE_PNG 
    (integer)
   
   IMAGETYPE_SWF 
    (integer)
   
   IMAGETYPE_PSD 
    (integer)
   
   IMAGETYPE_BMP 
    (integer)
   
   IMAGETYPE_WBMP
    (integer)
   
   IMAGETYPE_XBM
    (integer)
   
   IMAGETYPE_TIFF_II 
    (integer)
   
   IMAGETYPE_TIFF_MM 
    (integer)
   
   IMAGETYPE_IFF 
    (integer)
   
   IMAGETYPE_JB2 
    (integer)
   
   IMAGETYPE_JPC 
    (integer)
   
   IMAGETYPE_JP2 
    (integer)
   
   IMAGETYPE_JPX 
    (integer)
   
   IMAGETYPE_SWC 
    (integer)
   
   IMAGETYPE_ICO
    (integer)
   
   PNG_NO_FILTER 
    (integer)
   
   PNG_FILTER_NONE 
    (integer)
   
   PNG_FILTER_SUB 
    (integer)
   
   PNG_FILTER_UP 
    (integer)
   
   PNG_FILTER_AVG 
    (integer)
   
   PNG_FILTER_PAETH 
    (integer)
   
   PNG_ALL_FILTERS 
    (integer)
   
   IMG_FLIP_VERTICAL
    (int)
   
   IMG_FLIP_HORIZONTAL
    (int)
   
   IMG_FLIP_BOTH
    (int)
   
   IMG_BELL
    (int)
   
   IMG_BESSEL
    (int)
   
   IMG_BILINEAR_FIXED
    (int)
   
   IMG_BICUBIC
    (int)
   
   IMG_BICUBIC
    (int)
   
   IMG_BLACKMAN
    (int)
   
   IMG_BOX
    (int)
   
   IMG_BSPLINE
    (int)
   
   IMG_CATMULLROM
    (int)
   
   IMG_GAUSSIAN
    (int)
   
   IMG_GENERALIZED_CUBIC
    (int)
   
   IMG_HERMITE
    (int)
   
   IMG_HAMMING
    (int)
   
   IMG_HANNING
    (int)
   
   IMG_MITCHELL
    (int)
   
   IMG_POWER
    (int)
   
   IMG_QUADRATIC
    (int)
   
   IMG_SINC
    (int)
   
   IMG_NEAREST_NEIGHBOUR
    (int)
   
   IMG_WEIGHTED4
    (int)
   
   IMG_TRIANGLE
    (int)