Image Processing (GD)

• Introduction
• Installing/Configuring
  • Requirements
  • Installation
  • Runtime Configuration
  • Resource Types
• Predefined Constants
• Examples
  • PNG creation with PHP
  • Adding watermarks to images using alpha channels
  • Using imagecopymerge to create a translucent watermark
• GD Functions
  • gd_info — Retrieve information about the currently installed GD library
  • getimagesize — Get the size of an image
  • image_type_to_extension — Get file extension for image type
  • image_type_to_mime_type — Get Mime-Type for image-type returned by getimagesize, exif_read_data, exif_thumbnail, exif_imagetype
  • image2wbmp ⬠Output image to browser or file
  • imagealphablending ⬠Set the blending mode for an image
  • imageantialias ⬠Should antialias functions be used or not
  • imagearc ⬠Draws an arc
  • imagechar ⬠Draw a character horizontally
  • imagecharup ⬠Draw a character vertically
  • imagecolorallocate ⬠Allocate a color for an image
  • imagecolorallocatealpha ⬠Allocate a color for an image
  • imagecolorat ⬠Get the index of the color of a pixel
  • imagecolorclosest ⬠Get the index of the closest color to the specified color
  • imagecolorclosestalpha ⬠Get the index of the closest color to the specified color + alpha
  • imagecolorclosesthwb ⬠Get the index of the color which has the hue, white and blackness
  • imagecolordeallocate ⬠De-allocate a color for an image
  • imagecolorexact ⬠Get the index of the specified color
  • imagecolorexactalpha ⬠Get the index of the specified color + alpha
  • imagecolormatch ⬠Makes the colors of the palette version of an image more closely match the true color version
  • imagecolorresolve ⬠Get the index of the specified color or its closest possible alternative
  • imagecolorresolvealpha ⬠Get the index of the specified color + alpha or its closest possible alternative
  • imagecolorset ⬠Set the color for the specified palette index
  • imagecolorsforindex ⬠Get the colors for an index
  • imagecolorstotal ⬠Find out the number of colors in an image's palette
  • imagecolortransparent ⬠Define a color as transparent
  • imageconvolution ⬠Apply a 3x3 convolution matrix, using coefficient and offset
  • imagecopy ⬠Copy part of an image
  • imagecopymerge ⬠Copy and merge part of an image
  • imagecopymergegray ⬠Copy and merge part of an image with gray scale
  • imagecopyresampled ⬠Copy and resize part of an image with resampling
  • imagecopyresized ⬠Copy and resize part of an image
  • imagecreate ⬠Create a new palette based image
  • imagecreatefromgd2 ⬠Create a new image from GD2 file or URL
  • imagecreatefromgd2part ⬠Create a new image from a given part of GD2 file or URL
  • imagecreatefromgd ⬠Create a new image from GD file or URL
  • imagecreatefromgif ⬠Create a new image from file or URL
  • imagecreatefromjpeg ⬠Create a new image from file or URL
  • imagefilledarc ⬠Draw a partial arc and fill it
  • imagefilledellipse ⬠Draw a filled ellipse
  • imagefilledpolygon ⬠Draw a filled polygon
  • imagefilledrectangle ⬠Draw a filled rectangle
  • imagefilltoborder ⬠Flood fill to specific color
  • imagefilter ⬠Applies a filter to an image
  • imagefontheight ⬠Get font height
  • imagefontwidth ⬠Get font width
  • imageftbbox ⬠Give the bounding box of a text using fonts via freetype2
  • imagefttext ⬠Write text to the image using fonts using FreeType 2
  • imagegammacorrect ⬠Apply a gamma correction to a GD image
  • imagegd2 ⬠Output GD2 image to browser or file
  • imagegd ⬠Output GD image to browser or file
  • imagegif ⬠Output image to browser or file
  • imagegrabscreen ⬠Captures the whole screen
  • imagegrabwindow ⬠Captures a window
  • imageinterlace ⬠Enable or disable interlace
  • imageistruecolor ⬠Finds whether an image is a truecolor image
  • imagejpeg ⬠Output image to browser or file
  • imagelayereffect ⬠Set the alpha blending flag to use the bundled libgd layering effects
  • imageline ⬠Draw a line
  • imageloadfont ⬠Load a new font
  • imagepalettecopy ⬠Copy the palette from one image to another
  • imagepng ⬠Output a PNG image to either the browser or a file
  • imagepolygon ⬠Draws a polygon
  • imagepsbbox ⬠Give the bounding box of a text rectangle using PostScript Type1 fonts
  • imagepsencodefont ⬠Change the character encoding vector of a font
  • imagepsextendfont ⬠Extend or condense a font
  • imagepsfreefont ⬠Free memory used by a PostScript Type 1 font
  • imagepsloadfont ⬠Load a PostScript Type 1 font from file
  • imagepsslantfont ⬠Slant a font
  • imagepstext ⬠Draws a text over an image using PostScript Type1 fonts
  • imagerectangle ⬠Draw a rectangle
  • imagerotate ⬠Rotate an image with a given angle
  • imagesavealpha ⬠Set the flag to save full alpha channel information (as opposed to single-color transparency) when saving PNG images
  • imagesetbrush ⬠Set the brush image for line drawing
  • imagesetpixel ⬠Set a single pixel
  • imagesetstyle ⬠Set the style for line drawing
  • imagesetthickness ⬠Set the thickness for line drawing
  • iptcembed — Embed binary IPTC data into a JPEG image
  • iptcparse — Parse a binary IPTC block into single tags.
  • jpeg2wbmp — Convert JPEG image file to WBMP image file
  • png2wbmp — Convert PNG image file to WBMP image file