PHP: Displaying ImageMagick image without saving to server like GD - php

Question

This question has already been asked (see link below) but none of the answers work. So I have this ImageMagick script that I am using to tint PNGs and it works great but the problem is that it actually generates files on the server. What I want instead is exactly what GD does where it does the image manipulation and then displays it without actually saving an image.
Here is my ImageMagick code that I use to tint the image. This code does the converting and generates an extra file on the server which is the final image.
<?php
$source = "src.png";
$final = "FINAL.png";
$color = "#00FF00";
exec("convert $source -threshold 100% +level-colors '$color', $final");
?>
Here is a GD example code which does an image manipulation and displays the final image directly without saving extra images to the server:
<?php
header('Content-Type: image/png');
$source = "src.png";
$im = imagecreatefrompng($source);
imagefilter($im, IMG_FILTER_GRAYSCALE);
imagepng($im);
imagedestroy($im);
?>
So essentially I want the image manipulation that is done in the first example, but without saving extra images and displaying the output in the browser.
Links searched:
None of the solutions worked:
Generate images with ImageMagick without saving to file but still display them on website
How can I convert my ImageMagick code to iMagick? PHP-Imagemagick image display

Answer 1

A direct example using your code for others to learn from.
I use this same method on my shared Linux server on Godaddy.
<?php
$source = "src.png";
$color = "#00FF00";
$cmd = "convert $source -threshold 100% +level-colors '$color',".
" -unsharp 0.2x0.6+1.0 -quality 50 JPG:-";
header("Content-type: image/jpeg");
passthru($cmd, $retval);
exit();
?>
Note: - Are you sure you are using "-threshold 100% +level-colors '$color'," correctly? Threshold 100% will push an image to black. Which then +level-colors '#00FF00', will just make a solid green image. I am assuming you have simplified the code for this demonstration.
Note: - "+level-colors '$color'", does not work on Godaddy's servers. It works fine on my home server though. Possibly an outdated ImageMagick version installed on Godaddy's server.