Daniel Reetz, the founder of the DIY Book Scanner community, has recently started making videos of prototyping and shop tips. If you are tinkering with a book scanner (or any other project) in your home shop, these tips will come in handy. https://www.youtube.com/channel/UCn0gq8 ... g_8K1nfInQ

Manual-Only Picture Zone in Mixed Mode?

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jimboh
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Manual-Only Picture Zone in Mixed Mode?

Post by jimboh » 17 May 2011, 02:12

This relates to the Beta 11 snapshot with the following information:

last change Tue, 10 May 2011 22:02:08 +0000

I don't know whether I could do this before and have forgotten how, or whether I could never do this.

Although Mixed Mode allows me to create a picture zone on a mixed page, it seems I must also live with the automatic picture zone created by the program. What I want is the ability to reject the automatic picture zone so that I can use my picture zone, and only my picture zone, to the exclusion of what the program automatically selects, on a mixed page.

This is the source page, before processing with ST:
pose-111.tiff
(4.96 MiB) Not downloaded yet
The problem relates to the right-side page.

The output in Black & White looks like this:
b&wbeta11.png
b&wbeta11.png (224.55 KiB) Viewed 6114 times
All is good except the box at the bottom of the page.

This is what the Picture Zone page looks like in Mixed:
mixedbeta11.png
mixedbeta11.png (411.34 KiB) Viewed 6114 times
This is the output, showing the garbage preserved by the automatic picture zone:
pose-111_2R.tif
(729.57 KiB) Not downloaded yet
We should be able to reject all the automatic picture zoning in Mixed mode and use, instead, only our manual picture zones. If this is possible now, I cannot figure out how to do it.

Tulon
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Re: Manual-Only Picture Zone in Mixed Mode?

Post by Tulon » 17 May 2011, 02:39

The way around it is to draw a large zone that covers the whole page -> right click -> Properties -> Subtract from auto-layer.

BTW, the problem seems to be coming from a shadow that seems to have been binarized by dithering. If you scanned that book yourself, you could have avoided it by scanning in some mode other than B/W.
Scan Tailor experimental doesn't output 96 DPI images. It's just what your software shows when DPI information is missing. Usually what you get is input DPI times the resolution enhancement factor.

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jimboh
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Re: Manual-Only Picture Zone in Mixed Mode?

Post by jimboh » 17 May 2011, 02:47

Tulon wrote:The way around it is to draw a large zone that covers the whole page -> right click -> Properties -> Subtract from auto-layer.
Thanks, I'll do that.
Tulon wrote:If you scanned that book yourself, ...
Nope. I'm working from someone else's PDF.

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jimboh
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Re: Manual-Only Picture Zone in Mixed Mode?

Post by jimboh » 17 May 2011, 14:11

Tulon wrote:draw a large zone that covers the whole page -> right click -> Properties -> Subtract from auto-layer.
I am getting crashes from segmentation faults when I do the right mouse button. Rebooting does not help.

I don't know what to do with the debug menu item because all the side tabs, including Picture Zones, disappear when I select Debug. The top tabs do not seem to show picture zones.

I'm using ST on a Mac, compiled using the latest snapshot with the instructions at sourceforge.

Tulon
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Re: Manual-Only Picture Zone in Mixed Mode?

Post by Tulon » 17 May 2011, 17:27

That's an old and known problem on a Mac. The reason is a missing feature in Qt that I can easily emulate on Windows and Linux, but not on Mac OS X. I did report the problem to Qt developers, but apparently it was ignored. A couple of dirty workarounds are possible though. One of those is too dirty for me to accept, and the other one may be acceptable, but someone would have to actually implement it and submit a clean patch that's ready to be applied. I mean if you want me to do something I don't really want to do, at least make it easy for me. As I don't run OS X myself, don't count on me to do it. If I was running OS X, I would probably go with patching Qt itself rather than brining in dirty workarounds into Scan Tailor.

P.S: The problem was discussed in depth in this thread.
Scan Tailor experimental doesn't output 96 DPI images. It's just what your software shows when DPI information is missing. Usually what you get is input DPI times the resolution enhancement factor.

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jimboh
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Re: Manual-Only Picture Zone in Mixed Mode?

Post by jimboh » 17 May 2011, 18:10

I looked at the thread and it is all way over my head. The only thing I could do to help would be to try fixes and report back whether they work or not.

Would it be easier to allow us to "turn off" the automatic picture zoning on a Mixed page, as opposed to "excluding" it, and then to let us use a manual-only zone? (Of course, since I do not understand the technicalities of the problem, for all I know that is the very heart of the problem.)

Too bad the Qt folks won't fix their own bug!

Tulon
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Re: Manual-Only Picture Zone in Mixed Mode?

Post by Tulon » 17 May 2011, 18:24

jimboh wrote:Would it be easier to allow us to "turn off" the automatic picture zoning on a Mixed page, as opposed to "excluding" it, and then to let us use a manual-only zone?
Considering exclusion is already implemented and "manual only" picture zones are not, the answer is obvious.
jimboh wrote:Too bad the Qt folks won't fix their own bug!
It's not really a bug but a missing feature. I don't blame them, as I can imagine the number of problems getting submitted to them every day.
Scan Tailor experimental doesn't output 96 DPI images. It's just what your software shows when DPI information is missing. Usually what you get is input DPI times the resolution enhancement factor.

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jimboh
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Re: Manual-Only Picture Zone in Mixed Mode?

Post by jimboh » 29 May 2011, 15:47

No more crashes with the new patch for Mac OS X (last change Sun, 29 May 2011 08:01:34 +0000)!
Tulon wrote:draw a large zone that covers the whole page -> right click -> Properties -> Subtract from auto-layer.
With the new patch, this works on Mac OS X. Thanks!

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