Description:
------------
Gmagick 1.1.6RC2

setImageInterlaceScheme() has no affect on the output of an image in the provided code. Regardless of which constant is used.

Attempted constants:
INTERLACE_UNDEFINED
INTERLACE_NO
INTERLACE_LINE
INTERLACE_PLANE

$img->getImageInterlaceScheme() does properly return the value of the constant previously set.

I've described this at StackOverflow as well http://stackoverflow.com/questions/20386954/why-doesnt-setimageinterlacescheme-make-a-jpeg-progressive

Test script:
---------------
    $img = new Gmagick();
    $img->setSize(900, 900)
        ->readImageBlob($image->getBytes())
        ->setImageInterlaceScheme(Gmagick::INTERLACE_PLANE)
        ->setImageResolution(96, 96)
        ->setImageFormat('jpeg')
        ->setCompressionQuality(70)
        ->resizeImage(900, 1351, Gmagick::FILTER_UNDEFINED, 1);

Expected result:
----------------
Output of a progressive jpeg

Actual result:
--------------
Output of a baseline jpeg