This example shows how to set the negative color of an image in php gd.
This example shows how to set the negative color of an image in php gd.<?php
function
negate($image){
if(function_exists('imagefilter')){
return imagefilter($image, IMG_FILTER_NEGATE);}
for($x = 0; $x < imagesx($image); ++$x){
for($y = 0; $y < imagesy($image); ++$y){
$index = imagecolorat($image, $x, $y); $rgb = imagecolorsforindex($index); $color = imagecolorallocate($image, 255 - $rgb['red'], 255 - $rgb['green'], 255 - $rgb['blue']);imagesetpixel(
$im, $x, $y, $color);}
}
return(true);}
$image
= imagecreatefromjpeg('image1.jpg');if
($image && negate($image)){
echo 'Image successfully converted to negative colors.';imagejpeg(
$image, 'image1.jpg', 100);imagedestroy(
$image);}
else
{
echo 'Negative color conversion failed.';}
?>
After running the program you will get the following output