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RE: Profiling Canvas



Here's an update on the results of the two profiling methods used with the Oce canvas.  To review, normal profiling using Profiler RGB resulted in wildly posterized colors on a portrait of a young musician posing with her harp in front of a medium blue muslin background. Realizing the texture of the canvas probably corrupted the profiling process I blurred the calibration chart and repeated the calibration process.  This resulted in a print with beautiful skin tones and a very realistic burl veneer on the harp but somewhat posterized dark areas both in the background, the girl's hair and dark wood on the harp.  Of course I just realized that in blurring the calibration chart I erred by not masking out the corner dots used by the Profiler software so I'll go back tomorrow and try again.  I also tried a method offered by Mr. Tobie in which he suggested printing the calibration chart very large and reducing it prior to creating the profile. Doing so would compress the canvas text!
ure and th
   eoretically result in 

I think my results were skewed by the amount of color tweaking I did trying to get the image to print with acceptable colors.  I'm really very close and in the interest of science I may go back and rework the image from scratch to see if I can get it to fly.  In addition, I think a combination of the two methods described above might be best.  i.e. printing the calibration chart large then reducing AND blurring it making sure the only artifacts outside the target's colors are the four corner ticks which will be spared the effects of blurring.

One technical question that does arise from this situation is: how does Profiler read the calibration chart as it creates the profile?  How important is it to maintain a clear distinction or transition between the various colors on the chart and what effect does the blurring have on the ability of the software to gather the necessary information to create the profile?


Michael Plack

> ** Original Message follows... 

>
> In a message dated 5/12/01 7:22:52 PM, metphoto@pacbell.net writes:
> 
> >I'm trying to profile a canvas substrate that's giving Profiler RGB fits.
> >
> >Portraits printed with this canvas result in wild colors.  My take is the
> >
> >texture in the canvas has thrown off the profiling function.  I tried
> >
> >blurring the calibration chart which resulted in some improvement.  The
> >skin
> >
> >tones came out great (as opposed to yellow/green on an unblurred calibration
> >
> >chart) but the hair and background, both dark, are way off.
> >
> >
> >
> >Anyone found a way around this?
> 
> Try printing the target as large as your printer and scanner will allow, and 
> see if this increased patch size (plus your blurring if needed still) will 
> overcome the extreme texture.
> 
> C. David Tobie
> Design Cooperative
> CDTobie@designcoop.com
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>** --------- End Original Message ----------- **

> 

                   M e t r o   P  h  o  t  o  g  r  a  p  h  i  c
                     Specializing in Portrait Design and
                        Digital Photo Restoration

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