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

Picture Zone over-exposure Issue

Scan Tailor specific announcements, releases, workflows, tips, etc. NO FEATURE REQUESTS IN THIS FORUM, please.
Post Reply
univurshul
Posts: 496
Joined: 04 Mar 2014, 00:53

Picture Zone over-exposure Issue

Post by univurshul » 29 Oct 2010, 18:42

I prefer using 'mixed mode' in Scan Tailor, but why is it necessary to over-expose images & pictures that are otherwise properly bordered within picture zones?

I don't understand why it ST alters images & pictures the user doesn't intend to be altered. Rich-colored content appears bleached and faded, over-exposed in mixed-mode output. This lessens/alters the quality of the target image vs. the original image.

Is there a way to turn off illumination on pictures in mixed mode?

Here are some before & after examples of this occurring:
http://www.diybookscanner.org/forum/vie ... 6058#p6058

Tulon
Posts: 687
Joined: 03 Oct 2009, 06:13
Number of books owned: 0
Location: London, UK
Contact:

Re: Picture Zone over-exposure Issue

Post by Tulon » 30 Oct 2010, 18:08

Bleaching of images is a side effect of illumination equalization. You generally want that to happen, especially if your scans / shots are grayish. Unfortunately, illumination equalization just doesn't work well with images that reach the very edges of a book. It would be technically possible to enable / disable illumination equalization on a per-page or even per-zone basis.
At this point I would usually say I am not implementing any new features until I finish dewarping. Today I'll make an even stronger statement: I am not implementing any new features at all, until or after dewarping is done. The truth is, working on Scan Tailor stopped being fun a long time ago. There are still a couple of interesting things to work on, dewarping being one of them, so there is still a chance it will get done. For all other intents and purposes, consider myself retired from the project.
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.

univurshul
Posts: 496
Joined: 04 Mar 2014, 00:53

Re: Picture Zone over-exposure Issue

Post by univurshul » 30 Oct 2010, 18:34

I totally understand and wouldn't dare to make suggestions or submit improvement requests.

The posts I'm making here are for future dev teams and other software companies that specialize in scanning optimization. This post is a 'bookmark', if you will, that documents noted issues that could possibly be addressed at another time.

Being a Mac user myself, I'm trying to bring in teams such as Prizmo so that they can enhance their optimization tools; learn from our work and what we do with the software.

I can't speak for everyone here, but I'm sure there's an overwhelming agreement that you deserve a nice long vacation, Tulon.

spamsickle
Posts: 596
Joined: 06 Jun 2009, 23:57

Re: Picture Zone over-exposure Issue

Post by spamsickle » 31 Oct 2010, 11:48

Tulon wrote:I am not implementing any new features at all, until or after dewarping is done. The truth is, working on Scan Tailor stopped being fun a long time ago. There are still a couple of interesting things to work on, dewarping being one of them, so there is still a chance it will get done. For all other intents and purposes, consider myself retired from the project.
I had always assumed that implementing features which you thought were not a good idea -- the fixed content selection "apply to" being the most requested -- would have to happen outside the official Scan Tailor repository. However, if you're planning to retire from active development, is there any chance that you might pass the baton and permit others to make such enhancements to Scan Tailor itself?

Tulon
Posts: 687
Joined: 03 Oct 2009, 06:13
Number of books owned: 0
Location: London, UK
Contact:

Re: Picture Zone over-exposure Issue

Post by Tulon » 31 Oct 2010, 12:13

I would actually prefer a fork. Let me draw an analogy here. For years I was working on a painting but then decided to stop before it was finished. Now you are asking me would it be OK for you to take over and finish it. My answer would be sure, but please give it another name. I mean I may or may not like the changes you are going to make.
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.

Post Reply