Image Processing and 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 and Image Functions
  • gd_info — Retrieve information about the currently installed GD library
  • getimagesize — Get the size of an image
  • getimagesizefromstring — Get the size of an image from a string
  • 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
  • imagecreatefrompng — Create a new image from file or URL
  • imagecreatefromstring — Create a new image from the image stream in the string
  • imagecreatefromwbmp — Create a new image from file or URL
  • imagecreatefromwebp — Create a new image from file or URL
  • imagecreatefromxbm — Create a new image from file or URL
  • imagecreatefromxpm — Create a new image from file or URL
  • imagecreatetruecolor — Create a new true color image
  • imagedashedline — Draw a dashed line
  • imagedestroy — Destroy an image
  • imageellipse — Draw an ellipse
  • imagefill — Flood fill
  • 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
  • imageflip — Flips an image using a given mode
  • 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
  • imagepalettetotruecolor — Converts a palette based image to true color
  • 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
  • imagesetinterpolation — Set the interpolation method
  • imagesetpixel — Set a single pixel
  • imagesetstyle — Set the style for line drawing
  • imagesetthickness — Set the thickness for line drawing
  • imagesettile — Set the tile image for filling
  • imagestring — Draw a string horizontally
  • imagestringup — Draw a string vertically
  • imagesx — Get image width
  • imagesy — Get image height
  • imagetruecolortopalette — Convert a true color image to a palette image
  • imagettfbbox — Give the bounding box of a text using TrueType fonts
  • imagettftext — Write text to the image using TrueType fonts
  • imagetypes — Return the image types supported by this PHP build
  • imagewbmp — Output image to browser or file
  • imagewebp — Output an WebP image to browser or file
  • imagexbm — Output an XBM image to browser or file
  • iptcembed — Embeds 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