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

[Elle Stone <l elle stone gmail com>]

On 5/24/13, Mukund Sivaraman <muks banu com> wrote:
> The following file plug-ins have been revised to use GIMP's new API.
> I feel they need more testing as the changes are intrusive and the file
> types can support a variety of pixel formats. I have tested these to my
> satisfaction. Please test these if you can (master branch).

> * file-tiff-save (test saving grayscale, RGB and indexed TIFF files
>   incl. 16-bits per channel in the case of non-indexed)

Tiff vary a bit in their internal structure, depending on which
software generates the tiff, yes? So I'm planning on testing tiffs
from several sources.

I'm using Gentoo Linux. I rebuilt babl, gegl, and Gimp 2.9 from git
this morning. So far I've tested some old 8-bit and 16-bit single
layer tiffs that were created using Photoshop CS2 under Windows 2K (I
did say old!):

*8-bit and 16-bit color tiffs opened and exported properly; I was able
to open the exported files with showFoto and each file looked right
and had its appropriate bit depth.

*converting 8-bit tiff to 16-bit tiff and exporting worked.

*converting tiff to indexed and exporting worked.

*converting 8-bit and 16-bit color tiffs to grayscale and exporting
worked; the exported file opened with showFoto and looked exactly as
expected. However, opening the exported 8-bit and 16-bit
color-to-grayscale tiffs (that Gimp has just exported) with Gimp
instead of showFoto didn't work. The images were too light in
tonality, looked like they had been given a gamma 2.2ish correction.
Upon exporting the newly opened grayscale image under a new name, the
exported image then was also wrong in showFoto (showFoto can't
actually work with or save grayscale image, instead converts to RGB
before displaying the image).

*Tiffs can support multiple layers and higher than 16-bit precision,
which is not to say that Gimp is obligated to support these options.
Exporting a two-layer tiff didn't work. Only one layer was exported
and only about a third of the image on that layer was exported
properly. Also changing precision to 32-bit floating point and
exporting as a tiff resulted in a 16-bit tiff.

Elle