PHP: imagecolorexact

imagecolorexact

(PHP 3, PHP 4, PHP 5)

imagecolorexact -- Get the index of the specified color

Description

int imagecolorexact ( resource image, int red, int green, int blue )

Returns the index of the specified color in the palette of the image.

If the color does not exist in the image's palette, -1 is returned.

If you created the image from a file, only colors used in the image are resolved. Colors present only in the pallete are not resolved.

See also imagecolorclosest().

imagecolorexact

jbr at ya-right dot com
18-Feb-2006 12:38


A few notes about this function...



This function will only work on images where the palette is 256 colors or less. You also can not use imagetruecolortopalette() to reduce the palette on a true color PNG image that has greater than 256 colors in it's palette, then call this function. If you try to do this imagecolorexact() will report colors not being in the image when they are in the image!



1. works on png(s) 8bit/256 colors or less.

2. works on all gif(s)

3. does not work on any type of jpg/jpeg image.

info at educar dot pro dot br
16-Nov-2005 11:14


<?php



$src = "../images/pic.gif";



$red = 9;

$green = 9;

$blue = 4;



$pic0026 = imagecreatefromgif ( $src );



$ind = imagecolorexact ( $pic, $red, $green, $blue );



echo '<img src="../images/pic.gif" border="0" alt="pic" title="View pic" /><br /><br />';



echo "RED ( " . $red . " ) GREEN ( " . $green . " ) BLUE ( " . $blue . " )<br />-> Palette Index = " . $ind;



if ( $ind != -1 )

{

echo "<br />[ The color exists! ]";

}

else

{

echo "<br />[ The color does not exist! ]";

}



imagedestroy ( $pic );



?>