Remove Image background with php and save transparent png

Question

I am working on functionality that removes the white background of any image uploaded on the site working on the PHP platform. I have completed the uploading part but I am having issues with working on the functionality.

I came across this: Remove the white background from an image and make it transparent. But this does the reverse of what I wanted. Can someone help me do this?

Answer 1

As you only need single-color transparency, you can use this code:

$img = imagecreatefromstring($your_image); //or whatever loading function you need
$white = imagecolorallocate($img, 255, 255, 255);
imagecolortransparent($img, $white);
imagepng($img, $output_file_name);

This is the simplest way that define white with imagecolortransparent().
I hope this helps.