Re: [Gimp-developer] Test some file plug-ins in master branch

[Elle Stone <l elle stone gmail com>]

Pngs, tiffs, jpegs:

I did some more testing. I tried opening an assortment of pngs, jpegs,
and tiffs created by a variety of image editing programs (recent
versions of krita, cinepaint, showfoto, an older version of Photoshop,
and test images downloaded from the web), and Gimp opened them all
with no problem.

I more or less randomly tested changing the bit depth, changing to
indexed, and changing to grayscale various tifs, jpegs, and pngs
created by the various image editing programs and then exporting to
tif, jpeg, and png at various bit-depths. Gimp opens its own exported
files with no problems, as does showFoto, Cinepaint, and Krita.

The only issues I encountered have to do with multi-layer/page tiffs.
I don't know what is the difference between multilayer and multipage
tiffs, if there even is one. However, they are useful when blending
panoramas and HDR images created by hugin. And Photoshop and Cinepaint
both can export multilayer/page tiffs.

Gimp did properly import a multilayer/page tiff created by Cinepaint.
The order of the layers was reversed. I didn't try any layered images
with masks, though one image had three layers and alpha channels.

Gimp doesn't export a multilayer file as a multilayer/page tiff,
rather flattens before exporting.

As previously noted, if Gimp flattens/exports a 2-layer grayscale (as
opposed to color) tiff, showFoto can't open it.

Bottom line, with the possible exception of multilayer/page tiffs
(depending on what kind of support Gimp is supposed to have - import
seems good, export not), Gimp png, jpeg, and tiff file formats all
look/work just fine.


BMPs:

I also downloaded a couple of bmps from the web and converted them to
indexed, grayscale; converted them from sRGB to other ICC color
spaces; exported as pngs, jpgs, tiffs; and also exported one tiff as a
bmp.

I've never actually used a bmp, so I didn't know what to expect. But
everything seemed normal, except in the advanced options there is an
option to not embed color information, which I never checked.
Sometimes it seemed like after converting to another color space,
exporting, and reopening, the color space information was
intact/honored. Other times I needed to assign the right profile to
get the right colors. Someone who actually uses and understands bmps
should also check!

Elle


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