Re: QPcard 201 with gnome-color-manager

[Pascal de Bruijn <pmjdebruijn pcode nl>]

On Fri, May 4, 2012 at 9:42 AM, Richard Hughes <hughsient gmail com> wrote:
> Hey all,
>
> I'm sitting next to mizmo here at LGM and she wants to create a camera
> profile with a QPcard 201 which in theory we support.

Just curious for which camera? And for which application?

> I know the
> limited number of patches aren't going to produce a super profile

The ColorChecker doesn't have many patches either, but it's fine for
matrix profiles. I'd would probably use colprof -aG for something like
this.

> , but
> we were both stumped when g-c-m asks for the reference file which
> QPcards appear not to ship with the card, but it looks like a generic
> one is shipped with Argyllcms. Are we supposed to use the cie or cht
> file?

I think you need the .cie file.

I'm guessing the procedure with the QPcard is similar to that of the
ColorChecker, in that all the card are produced to a tight
specification to match a reference.

In contrast to IT8 charts (etc), which aren't (in theory) as strictly
quality controlled, but are batch (or sometimes even individually)
measured.

> Are there any instructions on how far to crop the tiff file --
> we can't seem to get the patch detection to work.

One of the thing that may be a problem is gamma... You can pass -G 1
to scanin, especially if the RAW converter output is still linear.

Regards,
Pascal de Bruijn