Re: Printing profile test targets WITHOUT photoshop
Re: Printing profile test targets WITHOUT photoshop
- Subject: Re: Printing profile test targets WITHOUT photoshop
- From: James Horne <email@hidden>
- Date: Tue, 15 Sep 2009 16:37:14 +1000
- Thread-topic: Printing profile test targets WITHOUT photoshop
Hi Folks
I ran with the suggestion that Preview should not affect the colours of the
output print target as long as I did not formally convert the colour profile
of the untagged image. I basically asked a chap who runs a profiling
service to try printing the same target from Preview and from CS3 and then
compare the scans with his profiling hardware. Unfortunately there is a
measurable difference between them. I don't know what exactly Preview is
doing but on the strength of this test it looks like I cannot use it for
printing profile targets.
Cheers
James
On 19/8/09 9:44 PM, "James Horne" <email@hidden> wrote:
> I had a little play with Klaus suggestion. I can configure the printer driver
> through CUPS with an appropriate media selection for the paper I wish to
> profile and colour management (or lack of) settings. I wasn't sure if it was
> suggested in fun or not but part of the solution seems sensible, to me at
> least. I wonder though what happens in the conversion to postscript in
> tiff2ps, presumably using libtiff, to rendering of colours. I might print my
> colour test chart out that way and again through my current method with
> Preview and see if there is any colour shift. If there is none it would
> probably confirm both methods are leaving the colour alone but if there was a
> difference it wouldn't tell me which method was changing it, only that there
> was a difference.
>
> Anyway, the immediate annoyance with submitting the tiff2ps postscript output
> was that it printed in portrait orientation and went off the edges of the
> paper and AFAIK one can only manage a 180 degree rotation. I had a play with
> Imagemagick "convert" function to achieve the same but there are different
> issues with scaling. My profiling service insists the colour charts do not
> get scaled, just 100% size centred on an A4 page. They don't really suggest
> converting to postscript either..........but hey you only live once!
>
> I'll probably have a little more play with the postscript conversion, at least
> until somebody wiser tells me I'm being a fool!
>
> Cheers
>
> J
>
>
> On 19/8/09 6:19 PM, "Graeme Gill" <email@hidden> wrote:
>
>> edmund ronald wrote:
>>> I can't be bothered to look at the Generic RGB Apple Profile, and I'm
>>> too dumb to figure out what is in a profile anyway - but maybe some of
>>> our tech geniuses here can tell us what it is, or just make us a
>>> genuine "do nothing" profile of some sort to act as a placeholder ?
>>
>> It doesn't work like that. The only type of real device profile
>> that will "do nothing" is the same profile that will be used
>> as the destination, the very (fragile) system that is now
>> (it seems) not working so reliably.
>>
>> You can make a device link "do nothing" profile, but this isn't
>> going to be a valid way of tagging an image made of device values.
>>
>> The correct, robust method is to tag the image with a flag
>> that says "Image is in output device space, do not color manage",
>> but unless someone like the ICC comes up with a standard that
>> uses the ICC format for such a thing (a meta profile), it is
>> still going to be printing system or operating system
>> and print file format dependent.
>>
>> [ If it were up to me there would be two flags:
>> Do not color transform.
>> Do not use calibration.
>> So that there was a way of tagging calibration system and
>> profiling test charts in a way that guarantees that they
>> are printed properly. That's what we did with Postscript
>> comments on the DICENet/Cyclone, and it worked very reliably.]
>>
>> Graeme Gill.
>>
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