[Openicc] Printing targets: App or driver ? Profiling RGB or CMYK

[Robert Krawitz]

On Tue, 17 May 2011 19:48:30 -0600, Chris Murphy wrote:
>
> On May 17, 2011, at 7:12 PM, Robert Krawitz wrote:
>
>> On Wed, 18 May 2011 03:09:02 +0200, edmund ronald wrote:
>>> I don't think the inter-device repeatability thing is FUD. Epson has a
>>> utility called ColorBase .
>>> 
>>> http://www.epson.co.uk/article/1227894377886;jsessionid*B3F015106553CA9FBDA79254832611.acc2
>> 
>> But it requires an external device (it specifies a Gretag MacBeth or
>> X-Rite color measurement device).  That sounds like it profiles the
>> printer.  A very nice convenience indeed, but it doesn't sound like
>> special sauce within the printer.
>
> Appears to only use the Epson print driver (nothing else is
> mentioned), so my take on this product is that it is merely
> updating/replacement (maybe supplementing?) the calibration tables
> formed by Epson in the printer - which in turn purportedly are only
> accessible or used with the Epson OS native print driver. Not even
> their own HTM has access to this path apparently.

It states "Use with GretagMacbeth or X-Rite colour measuring
devices".  That sounds to me like it needs an outboard measuring
device.  From that, it certainly could store information on the host,
right?

> The biggest differences I've seen printer to printer is with the
> 100% coverage of each colorant. By yanking down, sometimes
> substantially, on the per channel ink limit, everything else pretty
> much falls in line. On one printer I may need a 98% standard cyan
> limit, and another another printer with same lot # paper and ink and
> firmware it may be 91% - totally different amounts of ink.
>
> Whereas with the RGB Mac OS driver, I get virtually the same L*a*b*
> value for 0,255,255 on those same two printers. Clearly these are
> NOT the same colors being tested - but there's still much greater
> consistency between printers when using the OS native driver from
> Epson.

It sure would be interesting to capture some print jobs and take a
look at them...

-- 
Robert Krawitz                                     <rlk at alum.mit.edu>

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