How to change the color in a image using PHP

Question

I have an image of a bar code, and I want to change the black color to any other color that is more colorful. How can I do it in PHP?

Answer 1

If your image is monochrome then you can use the imagefilter() function:

$image = imagecreatefromjpeg('filename.jpg');
imagefilter($image, IMG_FILTER_COLORIZE, 0, 0, 255); // make it blue!
imagejpeg($image, 'filename.jpg');