Can phpthumb generate interlaced images for progressive browser display?

Question

Is it possible to generate interlaced images using phpthumb? Even if phpthumb doesn't generate interlaced images is there a safe walk-around that can be used to achieve this on a webapp that uses phpthumb for image processing?

I tried finding out if phpthumb has this feature and all i could come up with was this configuration directive in phpThumb.config.php file:

$PHPTHUMB_CONFIG['output_interlace'] = true;   // if true: interlaced output for GIF/PNG, progressive output for JPEG; if false: non-interlaced for GIF/PNG, baseline for JPEG.

I set mine to true and it is still not generating interlaced images.

Answer 1

I was wondering this myself and checking the phpthumb source looks like for the GD library it is only doing the interlacing when (1) calling the OutputThumbnail() method and (2) when using ImageMagick, the ImageMagickThumbnailToGD() method. Which won't get called as far as I can tell when your using the class and calling GenerateThumbnail()

Answer 2

A patch has been pushed to fix this - Now both OutputThumbnail and RenderToFile will generate a properly interlaced JPEG if the setting was enabled (true)