Groups > Corel > Corel PhotoPaing X3 > Re: Magenta color blotches... is the CPT file format truly lossless?




Re: Magenta color blotches... is the CPT file format truly
lossless?

Re: Magenta color blotches... is the CPT file format truly lossless?
Tue, 18 Mar 2008 20:56:35 -040
I thought that the CM was your issue! Unless your system is calibrated, 
which it is obviously not, there is no use in using the color management. 
You did not show us the actual settings of the import/export options you 
have selected? Whenever you open a file and the color space differs from the 
settings in your import dialog, the file will be converted from the import 
color space to the internal color space, which in your case might be a total 
mess, you can't just arbitrarily convert a files colorspace!

-- 
Alfred
http://www.alfredky.com
"Sean" <azurepicTHISISFORSPAM@yahooSPAM.com> wrote in message 
news:47e04f15_2@cnews...
> Jeff,
>
> I have tested your file, never making it into a jpg, to remove that from 
> the
> equation and re-attach it after multiple saves in PP.  It has clearly
> degraded.  So I attached my default color management settings for CMYK 
> work,
> though I leave files in RGB until conversion is needed.
>
> Then I repeated the test (test2.png) with the color management 
> import/export
> settings changed as per the 'losslesscm' screen capture.  There appears to
> be no change after multiple saves.
>
> So, here's my thinking (obviously flawed somewhere):  I left import color
> management on since I thought that would improve my likelihood of getting
> extra color info when importing files from cameras and other sources.  I
> left export color management off because any jpgs exported with this on 
> are
> huge with all that color info included.  I do web work from time to time 
> and
> also save out files for email to other people, etc.  I had no idea that 
> save
> and load, open and close with CPT's and CDR's were causing color changes 
> to
> my files.
>
> As for the other comment, that starting with jpg files means they continue
> to degrade... are you guys suggesting that I need to explicitly convert a
> jpg into a CPT or tiff before I import it into DRAW?  Or save it as a tiff
> before saving as a CPT?  I don't see that as a likely or realistic 
> workflow.
> The CDR and CPT file formats are supposed to be lossless, and I've never
> read that it matters what original format the files are in.  I have been
> using DRAW/PP since version 9, nearly nine years now, so I'm not a total
> newcomer.
>
> If this is truly the case with color management, that either both import
> export arrows need to be on (assumption, not tested) or both off (tested),
> then there should be a warning when we set it otherwise.  In fact, I 
> notice
> that the 'Optimized for desktop printing' color management settings have
> only the import arrow enabled.  So using this profile, we could also 
> expect
> bitmap degradation (not tested)?
>
> I appreciate your input.
> Sean
>
> "Jeff Harrison" <test@test.com> wrote in message 
> news:47e01451$1_3@cnews...
>> Hi Sean,
>>
>> I applaud your efforts to want to ensure everything is OK.
>>
>> Here is a test file I'd like you to quickly try, you are familiar with
>> your testing process.
>>
>> It's here are lossless 24 bit PNG, and covers pretty much the whole
>> spectrum. If anomalies appear, they should be revealed more readily in
>> this case.
>>
>> I see the blotches in your prev. examples, but for the moment let's
>> leave jpeg out of the equation - at every stage.
>>
>>
>> Jeff
>>
> 


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