DJ Mike's Tutorials: PHP Image Functions

Image Functions

A small sample of functions that work on images

• getimagesize()
  Returns an array with 4 elements.
  Index 0 contains the width of the image in pixels.
  Index 1 contains the height in pixels.
  Index 2 is a flag indicating the type of the image:
    1 = GIF,
    2 = JPG,
    3 = PNG,
    4 = SWF, Example Highlighted Code Text Hide
• imagedestroy()
  Frees any memory associated with image.
• gd_info()
  Returns information on the version of GD your server supports.
• header()
  Format: header("Content-type: image/png");
  Tells browsers to expect image information rather than HTML
• imagecolorallocate()
  Creates a color resource; a variable that defines a color.
• imagecreate()
  Creates an image resource.
  Format: imagecreate( width, height)
• imagefill() Fills an area with color
  Format: imagefill($image, $x, $y, $replacement_color);
• imagefilltoborder()
  Fills an area with color till a border color
  Format: imagefilltoborder($image, 10, 10, $border_color, $replacement_color);
• imagefilledrectangle()
  Draws a filled rectangle
  Format: imagerectangle( $image, $upper-left-x, $upper-left-y, $lower-right-x, $lower-right-x, $color )
• imagefilledpolygon()
  Draws a filled poygon
  Format: imagefilledpolygon( $image, $cooridinates_array, $number_of_corners, $color )
• imagegif()
  Outputs a gif to the browser or to a file.
• imagejpeg()
  Outputs a jpeg to the browser or to a file.
• imagepng()
  Outputs a png to the browser or to a file.
• imageline()
  Format: imageline( $image_resource, $x1, $y1, $x2, $y2, $color_resource );
• imagefilledpolygon()
  Draws a hollow poygon
  Format: imagefilledpolygon( $image, $cooridinates_array, $number_of_corners, $color )
• imagerectangle()
  Draws a hollow rectangle
  Format: imagerectangle( $image, $upper-left-x, $upper-left-y, $lower-right-x, $lower-right-x, $color )
• imagesetpixel()
  Format: imagesetpixel( $image_resource, $x, $y, $color_resource );
• imagesetthickness()
  Sets the thickness of the lines drawn when using imageellipse(), imagerectangle(), imagearc() and imagepolygon().
  Format: imagesetthickness( $image_resource, $thickness_in_pixels);

All Image Functions

The index of image functions on the official PHP web site is at http://www.php.net/manual/en/ref.image.php but it is so bloated (512K) that it can cause WebTVs to crash so I made my own list:

• exif configuration
• 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()
  Draw a partial ellipse
• 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 nearest to the given color
• 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 div 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 and resize
• 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 resource 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 resource from file or URL
• imagecreatefromxbm()
  Create a new image resource from file or URL
• imagecreatefromxpm()
  Create a new image resource from file or URL
• imagecreatetruecolor()
  Create a new true color image resorce
• imagedashedline()
  Draw a dashed line
• imagedestroy()
  Destroy an image resource
• imageellipse()
  Draw an ellipse
• imagefill()
  Flood fill
• imagefilledarc()
  Draw a partial ellipse and fill it
• imagefilledellipse()
  Draw a filled ellipse
• imagefilledpolygon()
  Draw a filled polygon
• imagefilledrectangle()
  Draw a filled rectangle
  
• imagefilltoborder()
  Flood fill to border
• 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
• imagegd()
  Output GD image to browser or file
• imagegd2()
  Output GD2 image to browser or file
• imagegif()
  Output GIF image to browser or file
• imagegrabscreen()
  
• imagegrabwindow()
  
• imageinterlace()
  Enable or disable interlace
• imageistruecolor()
  Finds whether an image is a truecolor image
• imagejpeg()
  Output JPEG 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()
  Draw 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()
  To draw a text string 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
• 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
• imagexbm()
  Output XBM image to browser or file
• iptcembed()
  Embed binary IPTC data into a JPEG image
• iptcparse()
  Parse a binary IPTC http://www.iptc.org/ block into single tags.
• jpeg2wbmp()
  Convert JPEG image file to WBMP image file
• png2wbmp()
  Convert PNG image file to WBMP image file

Created by DJ Mike from Santa Barbara