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

[Elle Stone <ellestone ninedegreesbelow com>]

> > > Here are links to some sample collections of copyrighted test images:
> > >
> > > http://www.pcstats.com/articleimages/200601/samsungspp2040_300dpi1.jpg
> > > http://www.northlight-images.co.uk/article_pages/test_images.html
> > > http://www.outbackphoto.com/printinginsights/pi048/essay.html

> > > So the first question is: What kind of test images, for what kinds of
> > > testing, do you all, as a diverse group of GIMP users and developers, wish
> > > you had access to?
> > >
> > > Elle

I know we have a diverse and talented group of GIMP users. It seems to 
me that assembling a good set of test images really does need to start 
with feedback from GIMP users as to what kind of test images they might 
find useful.

I already know which test images I've downloaded from the internet over 
the years, for what purposes. I also know which test images I've put 
together, and for what purposes. It could be that no one else would find 
these images useful.

So the important question is:

*What copyrighted or otherwise test images GIMP users might have 
downloaded from the internet and found useful, and
*what kinds of test images GIMP users might have already put together,
*for what particular testing purposes.

It could be the case that hardly any GIMP user has ever used any test 
images (doubtful).

It could be the case that the phrase "test image" needs further 
clarification. Here are some random examples of when an appropriate test 
image might be useful:

1. Somewhere in my collection of copyrighted test images that can't be 
shared, there is a brightly colored montage that includes buildings 
along a stretch of beach, a parrot, and a woman's face. I found that 
test image very useful for learning about various "conversion to black 
and white" routines.

2. Grayscale block and grayscale and color gradient images are useful 
for testing things like:

*How "LCMS2 plus the monitor+monitor-profile plus the GIMP color 
management settings" affects how dark an image can get before dark gray 
and black can't be visually distinguished.
*How smoothly the monitor+profile displays and the printer+profile 
prints smooth gradients.

3. A granger rainbow can be used for all kinds of testing, such as 
"Visually what kind of overlap is there between any given RGB working 
space and the monitor+profile" and "What happens when extremely 
saturated colors from a selected RGB working space are converted to the 
printer profile using perceptual intent".

So before getting too far down the road of randomly assembling images 
and hoping someone finds them useful enough to justify the time and 
effort that would be involved, I think it would be helpful, actually 
essential, to have feedback from at least a few GIMP users as to what 
kinds of test images you've used in the past (preferably with links to 
example test images), for what specific testing purposes.

Best regards,
Elle Stone
--
http://ninedegreesbelow.com
Color management and free/libre photography