Re: [Gimp-user] troubles with 32bit float...

[Ken Moffat <zarniwhoop ntlworld com>]

On Wed, Apr 26, 2017 at 06:01:05PM -0700, Casey Connor wrote:
> I'm having lots of issues with the 32bit tiffs that come out of G'MIC CLI
> processing in Linux (Kubuntu 16.10 in my case).
>
> They don't open properly in GIMP, or most any other software. There is
> clearly something going wrong somewhere, but I'm not sure where to file a
> report as I'm not sure where the root cause may be (GIMP, underlying tiff
> libraries, or G'MIC, etc.) If anyone has any insight, I'd appreciate it.

The problem with tiff is that it isn't a simple format, it's a
specification which has been described as Thousands of Incompatible
File Formats (thanks, wikipedia).  When I was trying 16-bit images
with gimp-2.9 using ufraw, I used to see lots of messages about
unexpected features in the file format.  In the end I moved to pngs,
and for my amateur pics 8-bit is actually good enough.

So the first question is: can you use a different file format (I'm
only minimally familiar with G'MIC, used as a plugin, and I have no
real understanding of what you are doing) ?

> When I apply a -median_files filter with G'MIC, it generates a 32bit float
> file that opens as all-white in GIMP. But I can change the precision (in
> GIMP) from 32bit-float to any integer format, and the image suddenly appears
> and I can work with it just fine. Here is a demonstration image:
> http://caseyconnor.org/pub/image/32bitfloat.zip (145MB)

I recognize that G'MIC is not only for the gimp, but since it works
as a plugin working on opened images - can you use the plugin to do
what you are doing ?  If not, I would be tempted to ask at G'MIC
because they seem to be active and some of their output clearly
works in the gimp.  If they say it's not their problem, perhaps they
can narrow down whose problem it might be.

Sorry this probably isn't a lot of help.

ĸen
-- 
I live in a city. I know sparrows from starlings.  After that
everything is a duck as far as I'm concerned.  -- Monstrous Regiment