[argyllcms] Re: bin/average: averaging and possible outlier elimination for three or more .ti3 sets?

  • From: Klaus Karcher <lists@xxxxxxxxxxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Mon, 31 Aug 2009 19:53:14 +0200

Graeme Gill wrote:
edmund ronald wrote:
I think you can expect misreads regularly with an i1Pro.

That's not been my experience with the Argyll driver, but I'd
be interested to hear what others experience is.

We use chartread regularly for proof evaluation. We measure the "official" Fogra Media wedge v3 with an eye-one pro rev. A in bidirectional mode. We have measured approx. 2000 proofs within the last 10 months.

The layout of the Fogra Media wedge is not ideal: the spacers are black and white only and contrast between adjoining patches is partially very low -- see <http://www.fogra.org/products-de/pdfs/digital/i-Medienkeil+Media_Wedge.pdf> page 2.

We get unreported obvious misreads in approx. 3% of the cases and less clearly identifiable minor inaccuracies in approx. 5-15% of the cases.

Misreads occur more often with low-contrast proofs (e.g. Newspaper simulation).

When I measure larger charts with the eye-one, I hardly ever get Delta E max < 1 between two successive readings of the same chart with argyll as well as with XRite's MeasureTool -- and I'm sure the reason is not the lacking repeatability of the printer, but of the eye one in stripe mode.

Klaus

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