I'm trying to retrieve large images from a directory outside of the root directory. At the moment I just use "fpassthru", but this loads the image either progressively or interlaced depending on what is was when uploaded.
How do I create a complete copy of an image but convert it to interlaced without losing any quality or detail with PHP?
If you use the GD libraries that come with PHP, you can use imageinterlace
to accomplish this.
Here's from the example:
<?php
// Create an image instance
$im = imagecreatefromgif('php.gif');
// Enable interlancing
imageinterlace($im, true);
// Save the interlaced image
imagegif($im, './php_interlaced.gif');
imagedestroy($im);
?>
Alternately, you could use ImageMagick.