Question

I am looking for a php function that could obtain a gradient coloured filter from a grayscale or monochrome image like following. I know how to colour pixels as static color but not how to apply this kind of filter. Thank you.

Answer 1

Use this php function:

<?php
$image = imagecreatefrompng('image1.png');
imagealphablending( $image, false );
imagesavealpha( $image, true );
imagefilter($image, IMG_FILTER_COLORIZE, 255, 0, 0);  // 0,0,0 (RGB)
imagepng($image, 'img_filter_colorize_255_0_0.png');
imagedestroy($image);
?>

Then show your new image:

<img src="img_filter_colorize_255_0_0.png">