imagecolormatch
(PHP 4 >= 4.3.0, PHP 5)
imagecolormatch — Makes the colors of the palette version of an image more closely match the true color version
Description
bool imagecolormatch
( resource
$image1
, resource $image2
)Makes the colors of the palette version of an image more closely match the true color version.
Parameters
-
image1 -
A truecolor image link resource.
-
image2 -
A palette image link resource pointing to an image that has the same size as
image1.
Return Values
Returns TRUE on success or FALSE on failure.
Examples
Example #1 imagecolormatch() example
<?php
// Setup the true color and palette images
$im1 = imagecreatefrompng('./gdlogo.png');
$im2 = imagecreate(imagesx($im1), imagesy($im1));
// Add some colors to $im2
$colors = Array();
$colors[] = imagecolorallocate($im2, 255, 36, 74);
$colors[] = imagecolorallocate($im2, 40, 0, 240);
$colors[] = imagecolorallocate($im2, 82, 100, 255);
$colors[] = imagecolorallocate($im2, 84, 63, 44);
// Match these colors with the true color image
imagecolormatch($im1, $im2);
// Free from memory
imagedestroy($im1);
imagedestroy($im2);
?>
Notes
Note: This function requires GD 2.0.1 or later (2.0.28 or later is recommended).
- PHP Руководство
- Функции по категориям
- Индекс функций
- Справочник функций
- Обработка и генерация изображений
- Обработка изображений и GD
- gd_info
- getimagesize
- getimagesizefromstring
- image_type_to_extension
- image_type_to_mime_type
- image2wbmp
- imageaffine
- imageaffinematrixconcat
- imageaffinematrixget
- imagealphablending
- imageantialias
- imagearc
- imagechar
- imagecharup
- imagecolorallocate
- imagecolorallocatealpha
- imagecolorat
- imagecolorclosest
- imagecolorclosestalpha
- imagecolorclosesthwb
- imagecolordeallocate
- imagecolorexact
- imagecolorexactalpha
- imagecolormatch
- imagecolorresolve
- imagecolorresolvealpha
- imagecolorset
- imagecolorsforindex
- imagecolorstotal
- imagecolortransparent
- imageconvolution
- imagecopy
- imagecopymerge
- imagecopymergegray
- imagecopyresampled
- imagecopyresized
- imagecreate
- imagecreatefromgd2
- imagecreatefromgd2part
- imagecreatefromgd
- imagecreatefromgif
- imagecreatefromjpeg
- imagecreatefrompng
- imagecreatefromstring
- imagecreatefromwbmp
- imagecreatefromwebp
- imagecreatefromxbm
- imagecreatefromxpm
- imagecreatetruecolor
- imagecrop
- imagecropauto
- imagedashedline
- imagedestroy
- imageellipse
- imagefill
- imagefilledarc
- imagefilledellipse
- imagefilledpolygon
- imagefilledrectangle
- imagefilltoborder
- imagefilter
- imageflip
- imagefontheight
- imagefontwidth
- imageftbbox
- imagefttext
- imagegammacorrect
- imagegd2
- imagegd
- imagegif
- imagegrabscreen
- imagegrabwindow
- imageinterlace
- imageistruecolor
- imagejpeg
- imagelayereffect
- imageline
- imageloadfont
- imagepalettecopy
- imagepalettetotruecolor
- imagepng
- imagepolygon
- imagepsbbox
- imagepsencodefont
- imagepsextendfont
- imagepsfreefont
- imagepsloadfont
- imagepsslantfont
- imagepstext
- imagerectangle
- imagerotate
- imagesavealpha
- imagescale
- imagesetbrush
- imagesetinterpolation
- imagesetpixel
- imagesetstyle
- imagesetthickness
- imagesettile
- imagestring
- imagestringup
- imagesx
- imagesy
- imagetruecolortopalette
- imagettfbbox
- imagettftext
- imagetypes
- imagewbmp
- imagewebp
- imagexbm
- iptcembed
- iptcparse
- jpeg2wbmp
- png2wbmp
Коментарии
This function is a godsend! It works exactly as documented.
I'm working on an application where I need to take a transparent GIF, matte the GIF on a user defined background color, and finally scale the GIF based on a user defined %.
The only way I could get this to work so that the final image was high quality, ie: no jagged edges, and a smooth scale, was to convert the GIF to a JPG, and then copy the JPG into a new GIF image like this:
// open transparent gif
$GIFimg = imagecreatefromgif($file_path);
// create jpg image
$JPGimg = imagecreatetruecolor($width, $height);
// copy GIF to JPG
imagecopy($JPGimg, $GIFimg, 0, 0, 0, 0, $width, $height);
// create a true color image
$JPGscaled = imagecreatetruecolor($n_width, $n_height);
// scale the new JPG using the truecolor image
imagecopyresampled($JPGscaled, $JPGimg, 0, 0, 0, 0, $new_width, $new_height, $width, $height);
// create final GIF image
$GIFfinal = imagecreate($n_width, $n_height);
// copy the scaled JPG back to a GIF
imagecopymerge($GIFfinal, $JPGscaled, 0, 0, 0, 0, $n_width, $n_height, 100);
This worked great except the final step, copying the JPG to a GIF. If the JPG had too many colors, the function would index the colors to make it a palette image. So what would end up happening is the final image contained INCORRECT colors.
Adding this one line at the bottom of the code fixed everything.
imagecolormatch($JPGscaled, $GIFfinal);
I hope this helps anyone who is converting images back and forth and dealing with palette issues and color correction. Also, be aware that the above code is a sample and will not work by copying and pasting.
This function appears to work by changing the values of the colors of the paletted image -- no good if you're trying to force the resultant image to stick with certain pre-defined color values.Those that have Ubuntu servers note, that this function is added in PHP's GD library fork and is not available by default in Ubuntu php5-gd package.
Here's how-to install the PHP GD version: http://preview.tinyurl.com/yel4r7t