[Gimp-user] Test images and test suite (was Re: [Gimp-developer] GIMP should fork babl and GEGL)

[Elle Stone <ellestone ninedegreesbelow com>]

On 11/06/2014 11:24 AM, Gary Aitken wrote:
> Even if the result is not obvious visually, I need a heads-up
> so I can pay close attention to what's happening and undo the
> operation if appropriate.

On 11/07/2014 04:25 AM, Simos Xenitellis wrote:
> Is there a test suite available that could show the expected behavior?
> If not, let's try to build one, both the test-suite code plus the images
> (before/after).

As Gary hinted, when doing "X" to an image, whatever "X" might be, 
sometimes results are visually obvious and sometimes not. Many times 
when editing images, I've done "X" and thought "X" was just fine, only 
to realize later that "X" had changed the file in an unwanted way that 
only became obvious several editing steps later.

And sometimes "X" can make a change in an image that the monitor's 
limited color gamut can't display, that might only pop up visually when 
the image is printed or displayed on a wider gamut display.

There are a lot of nice copyright-encumbered test images available on 
the internet, but not many "copyleft" test images, and not many images 
that reflect the full range of colors as captured by digital cameras and 
then interpreted using typical matrix input profiles.

When I was testing unbounded sRGB image editing, the first task was to 
put together some appropriate test images and then figure out which 
tests needed to be made, as per Simos's "test suite".

A good test suite of "copyleft" images would be a nice thing to have, 
whether for testing new and existing editing algorithms, or for whatever 
testing that individual GIMP users might want to do on their own 
(printer-related, for example).

Best regards,
Elle Stone