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

ST consistently missing page numbers...

Scan Tailor specific announcements, releases, workflows, tips, etc. NO FEATURE REQUESTS IN THIS FORUM, please.
Post Reply
User avatar
JonEP
Posts: 81
Joined: 19 Apr 2010, 15:09

ST consistently missing page numbers...

Post by JonEP » 20 Dec 2010, 16:22

Hi all,

Just trying to get Scan Tailor to include page numbers in the content area. Does anyone have any idea how to coax ST to do this, without having to manually drag the content area box boundaries up for each page (in a 600 page book)?

Thanks, I'm attaching a sample image.
ScreenShot168.jpg
Here's a screen shot of a sample content area rendered by ST, in same book.
ScreenShot168.jpg (282.69 KiB) Viewed 4146 times
028a.jpg
this is an original jpeg which produces the same problem, cropped slightly to encourage ST to split the page in the proper place.

User avatar
daniel_reetz
Posts: 2786
Joined: 03 Jun 2009, 13:56
E-book readers owned: Used to have a PRS-500
Number of books owned: 600
Country: United States
Contact:

Re: ST consistently missing page numbers...

Post by daniel_reetz » 20 Dec 2010, 21:06

First things first...are you using the latest version? There have been several updates that helped deal with this problem. There have been a number of threads about it... here's one where Tulon gives a hint: http://diybookscanner.org/forum/viewtopic.php?f=8&t=373

I'm not saying it's been solved, but it has come up before.

Shaknum
Posts: 91
Joined: 16 Aug 2010, 13:10

Re: ST consistently missing page numbers...

Post by Shaknum » 21 Dec 2010, 00:53

Also, I think cropping the wood and screws out of the picture will work wonders as well. Give it a shot, it can't hurt.

lexicographer

Re: ST consistently missing page numbers...

Post by lexicographer » 21 Dec 2010, 05:38

I tested the scan (p.11) you posted and the pagenumber was included in the selected area after I had converted the scan to greyscale. I noticed that the left and right margin of p.11 (i.e. top and bottom of the page) were significantly less well lit than the center (or is it the fault of the camera/lens, i.e. vignetting?). If the lighting is uneven, correcting that might improve your results.
Last edited by lexicographer on 21 Dec 2010, 08:12, edited 2 times in total.

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

Re: ST consistently missing page numbers...

Post by Tulon » 21 Dec 2010, 07:46

You have a very low DPI there - maybe 70 or 80. That's way below what Scan Tailor will even accept. To make it accept those shots, you obviously had to specify a larger DPI than you really had, which makes content selection even less accurate.
The reason ST doesn't accept anything below 150 DPI is that you just won't get good results from that kind of input.
The way to go is to zoom in, if possible. I mean, your camera obviously doesn't have too many megapixels, so you don't want to waste any of them.
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.

User avatar
JonEP
Posts: 81
Joined: 19 Apr 2010, 15:09

Re: ST consistently missing page numbers...

Post by JonEP » 21 Dec 2010, 10:04

Hi all, thanks for the help.

Will try to zoom a bit more, and perhaps treat myself to better cameras in the near future (I'm using Canon A590s...).

RE: pixels, 1 inch of the book (about 3.5 lines of text because it is an odd printing) was about 158 pixels... Will have to go back and check again.

bnz

Re: ST consistently missing page numbers...

Post by bnz » 21 Dec 2010, 14:39

I also consistently have these problems, also at higher dpi's. I am just wondering whether there is anything useful one can do to preprocess the images for example in Lightroom to make it easier for Scantailor to detect the edges. As I don't know how the algorithm works, playing around without this knowledge probably won't help much.

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

Re: ST consistently missing page numbers...

Post by Tulon » 21 Dec 2010, 15:32

In some cases you can do something, in others you can't. I can't tell without looking at the original shot. Lowering input DPI below the actual value may help sometimes.
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