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<!-- received="Tue Mar 16 07:35:13 1999 PST" -->
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<!-- sent="Tue, 16 Mar 1999 16:34:09 +0100" -->
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<!-- name="Ewald R. de Wit" -->
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<!-- email="ewald@pobox.com" -->
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<!-- subject="Re: HP Photosmart R032 problem" -->
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<!-- inreplyto="19990316083410.60409@ux11.cso.uiuc.edu" -->
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<title>sane-devel: Re: HP Photosmart R032 problem</title>
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<h1>Re: HP Photosmart R032 problem</h1>
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<b>Ewald R. de Wit</b> (<a href="mailto:ewald@pobox.com"><i>ewald@pobox.com</i></a>)<br>
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<i>Tue, 16 Mar 1999 16:34:09 +0100</i>
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<p>
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<ul>
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<li> <b>Messages sorted by:</b> <a href="date.html#160">[ date ]</a><a href="index.html#160">[ thread ]</a><a href="subject.html#160">[ subject ]</a><a href="author.html#160">[ author ]</a>
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<li> <b>Next message:</b> <a href="0161.html">Petter Reinholdtsen: "New libtool 1.2f works fine on HP/UX 10.20"</a>
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<li> <b>Previous message:</b> <a href="0159.html">Mentore #cat# Siesto: "Re: Epson backend"</a>
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</ul>
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john allen pitney (<a href="mailto:pitney@students.uiuc.edu">pitney@students.uiuc.edu</a>) wrote:<br>
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<p>
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<i>> $ xscanimage [program starts, I choose /dev/scanner]</i><br>
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<i>> Preview Window [window appears]</i><br>
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<i>> [feed slide to PS, PS pulls in the slide a few mm]</i><br>
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<i>> Acquire Preview [preview acquired as slide feeds *into* the PS]</i><br>
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<i>> [preview looks okay, needs a lot of gamma correction 1.0 -> 2.2 or so]</i><br>
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<i>> [slide is now *inside* the scanner]</i><br>
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<i>> Scan [image is acquired as slide is pushed back *out* of the scanner]</i><br>
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<i>> [so far, so good]</i><br>
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<i>> Acquire Preview [again]</i><br>
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<i>> [this time, the preview is acquired and the slide returns to its </i><br>
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<i>> *out* position, unlike the first time]</i><br>
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<i>> Scan [this time, the slide feeds slowly back into the scanner, then </i><br>
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<i>> immediately reverses direction, and *then* data is acquired. Also, I </i><br>
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<i>> believe this is where the few mm of slip occurs.]</i><br>
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<p>
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This is normal behaviour for this scanner, it also happens with the <br>
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HP windows software. Vuescan doesn't do a second pass over the slide<br>
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(or strip) as it scans everything at once - perhaps that's why you<br>
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haven't noticed this particular behaviour before. The stupidity seems<br>
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to be internal to the scanner.<br>
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<br>
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<i>> Also, my test slide is a fairly typical scene, albeit without any sky </i><br>
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<i>> showing. I find that the default straight gamma curve results in a very </i><br>
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<i>> dark image--to fix it with gimp's levels tool, I need to set the white </i><br>
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<i>> point to 153 (out of 255) and the gamma to about 2.50. Of course, the </i><br>
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<i>> image gets reduced to something like 5 bits of precision after that kind </i><br>
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<i>> of rough treatment. Does this mean the R032 is going to require a </i><br>
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<i>> downloaded tone map just to produce a decent image?</i><br>
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<p>
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For dark slides, increase the Exposure Time to for example 300% and<br>
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apply a gamma of 2.2 if you have a PC monitor.<br>
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<p>
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About tonemaps, I feel it is better to do this in software (on the<br>
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frontend side) instead of implementing it for every backend.<br>
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Adding some intelligence or densitometric data to the frontend will<br>
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benefit all scanners and not just the Photosmart.<br>
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<p>
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<i>> Last night, I tried looking at a log file produced by VueSmart. I put </i><br>
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<i>> some up at the following URLs:</i><br>
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<p>
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I don't know of any interesting SCL options that this scanner could<br>
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still have and that's not incorporated into the newest backend<br>
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already. What is it that you are looking for in the vuesmart logs that<br>
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you like to have?<br>
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<p>
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<pre>
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--
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-- Ewald
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<p>
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<p>
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<p>
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<pre>
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--
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</pre>
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<p>
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<ul>
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<!-- next="start" -->
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<li> <b>Next message:</b> <a href="0161.html">Petter Reinholdtsen: "New libtool 1.2f works fine on HP/UX 10.20"</a>
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<li> <b>Previous message:</b> <a href="0159.html">Mentore #cat# Siesto: "Re: Epson backend"</a>
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<!-- nextthread="start" -->
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</ul>
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