[argyllcms] Re: Generating a target from a reference file

  • From: Pascal de Bruijn <pmjdebruijn@xxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Fri, 27 Mar 2009 17:59:13 +0100

On Thu, Mar 26, 2009 at 9:16 PM, Pascal de Bruijn <pmjdebruijn@xxxxxxxxx> wrote:
> On Thu, Mar 26, 2009 at 9:01 PM, Pascal de Bruijn <pmjdebruijn@xxxxxxxxx> 
> wrote:
>> On Thu, Mar 26, 2009 at 6:56 PM, Lars Tore Gustavsen
>> <lars.tore@xxxxxxxxxxxxxx> wrote:
>>> On Thu, Mar 26, 2009 at 6:01 PM, Pascal de Bruijn <pmjdebruijn@xxxxxxxxx> 
>>> wrote:
>>>> On Thu, Mar 26, 2009 at 2:22 PM, Graeme Gill <graeme@xxxxxxxxxxxxx> wrote:
>>>>>> Not exactly, preferably to RGB... Not all image editor can handle Lab.
>>>>>> And I'd like to read back the RGB, to generate a newly (edited),
>>>>>> reference file...
>>>>> I thought that's what I outlined last time.
>>>> I'm probably confusing terminology, which in turn is confusing you :)
>>>> The point of the exercise would be to read back the edited image,
>>>> as a new similar (but edited) reference file.
>>>> 1. Convert R080505.txt into an image of an IT8 chart, with the patch colors
>>>> generated from the text file.
>>> I just had to play with this. Do you mean something like this:
>>> sed   -n '17,304p' R080505.txt |awk '{print "convert -colorspace LAB
>>> -size 118x94 \"xc:LAB("$5"%,"$6"%,"$7"%)\" " $1".png\n"}' > run.sh
>>> Then you have to join them. I think there is a hint for that in the
>>> url posted above. I have to play with the kids now..
>> I was already fiddling with your scripts, adapting it. I attached my
>> results. And
>> scanin does recognize the image.
>> Now I need to see if I can read back the image as a reference file, with
>> (nearly) identical values. But that's something for tomorrow.
> Scanning back isn't that hard. I've included that script as well.
> However, for the conversion from the reference file, to the image, I have
> no explicit color space defined. So that's probably why the read back
> data it's matching the original data.

I'm finding it hard, to get the same values read back...

Also, the generated image seems yellowish... Possibly because of a
whitepoint mismatch?

When converting from XYZ imagemagick seems to output Linear RGB,
but in what color space... Anybody have a good guess?

I'd appreciate any suggestions...

Pascal de Bruijn

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