Yet another PDF to LRF converter

[cacapee]

Fixing white space marks can be done by using the Trim% feature. Click preview and move the left, top, bottom, right markers so that you crop out what you don't need. You don't have to be very accurate since pdflrf's whitespace removal takes care of the rest.

[ereszet]

JSWolf, I see that you moved my Software Tools post from Reader Accessories to this thread. It is all right with me but it discontinues the logical thread from Paper to Reader, including the hardware setup. I will make aware visitors to Acessories about tha move. However, I am not sure how to refer them to the new place of my post. I can only find it by searching for my own posts and not for number 177. How do one finds post number 177?

[ereszet]

Originally Posted by cacapee

Fixing white space marks can be done by using the Trim% feature. Click preview and move the left, top, bottom, right markers so that you crop out what you don't need. You don't have to be very accurate since pdflrf's whitespace removal takes care of the rest.

It is a great feature of pdflrf but it will not work with book pages whose margins change from page to page (like a lot of them available in digital libraries or in photos taken without a cradle and a tripod). In addition, white space removal (another magnificent feature of pdflrf) will not work with whitespace stained by black spots or blobs. You get a lot of them in photos of old books or if you split double pages in two (black/gray shadow in the middle of the original photo becomes black/gray shadow at the margins of the resulting two pages. It shows as black lines/blobs after converting to black and white. So a number of books require preprocessing before going to pdflrf. I will post my experience with that at a later stage, if you believe that my Software Tool theme belongs to this thread.

BTW. I take my photos with the black background, so I use programs to remove black background first and whitespace after that.

[JSWolf]

Originally Posted by ereszet

JSWolf, I see that you moved my Software Tools post from Reader Accessories to this thread. It is all right with me but it discontinues the logical thread from Paper to Reader, including the hardware setup. I will make aware visitors to Acessories about tha move. However, I am not sure how to refer them to the new place of my post. I can only find it by searching for my own posts and not for number 177. How do one finds post number 177?

#177 in this thread. Each post in a thread is numbered. So just go to the page and post with #177.

[cacapee]

Have you loooked into unpaper?

[JSWolf]

Originally Posted by cacapee

Have you loooked into unpaper?

What is unpaper?

[cacapee]

http://unpaper.berlios.de/

I haven't personally used it.

[NatCh]

best Google-guess: http://unpaper.berlios.de/

[ereszet]

Originally Posted by cacapee

Have you loooked into unpaper?

I was in touch with the author a few weeks ago to learn how to pipe jpg images to unpaper and save results as jpg as well. His advice was good for Linux but I have not managed to repeat it in DOS yet (however the DOS version packaged in pdfread works well with ppm/pbm/pgm).

Both versions - Linux and DOS - work nicely in batch mode. After experimenting with some parameters one can clean the image from black spots, lines and blobs with the result being masks (or blocks of text/image) surrounded by whitespace. His algorithm for conversion to black and white is based on the threshold method, which is not sufficient for poor quality originals. One has to keep in mind that even with cleaning parameters adjusted to clean one page, the processing may damage other pages by removing the text as well.

A nice feature of unpaper is splitting of double pages and replacing the dark shadow between the pages or at the margins with whitespace.

I asked the author to consider trimming the white space automatically once the program recognized the masks. He may do that in the future but not too soon.

For now, it is a good free preprocessing tool for pdflrf.

[ereszet]

Originally Posted by JSWolf

#177 in this thread. Each post in a thread is numbered. So just go to the page and post with #177.

It was not possible for me in the hybrid mode. Only now I discovered that posts are numbered sequentially in linear mode.

[ereszet]

Originally Posted by cacapee

Fixing white space marks can be done by using the Trim% feature. Click preview and move the left, top, bottom, right markers so that you crop out what you don't need. You don't have to be very accurate since pdflrf's whitespace removal takes care of the rest.

A poor quality original jpg is attached. Pdflrf can do little to improve it unless one manually trims the black margins (different for different pages), see the attached lrf file.
After preprocessing with ClearImage (demo version) and Finereader8 (commercial) the jpg is much improved although some black lines at the margin remain (more aggresive preprocessing would remove parts of text as well). Then, pdflrf can be used more effectively.

BTW. The image is a photoscan of a 1914 Russian calendar. I can make a better photo of it by zooming to individual rather than double pages, putting white paper to avoid effects of transparency, etc., but the photo in example is just to make my point about the need for preprocessing.

[cszhy]

Originally Posted by cacapee

PM me a link to the file. I'll see what the problem is.

It's in Chinese , thanks

[bookworm]

Cacapee.
Thanks for your good program. However, is there a way that you can use the size button (S M L) on the Sony ereader with your program. After converting to LRF file the sizing does not work.
Thanks

[JSWolf]

Originally Posted by bookworm

Cacapee.
Thanks for your good program. However, is there a way that you can use the size button (S M L) on the Sony ereader with your program. After converting to LRF file the sizing does not work.
Thanks

The size button won't work. pdflrf converts the PDF into images in LRF format. Sinze the resulting file is not text, you cannot change the font size. It's also not relflowable. So what you get is what you see.

[ereszet]

Originally Posted by JSWolf

The size button won't work. pdflrf converts the PDF into images in LRF format. Sinze the resulting file is not text, you cannot change the font size. It's also not relflowable. So what you get is what you see.

I am under impression that the size button works sometimes with pdf files (S and M), because the Reader tries to trim the white margins. After trimming the whitespace with pdflrf there is no longer room for expansion.

However, if you convert pdf to images, you can scale them up. Let us wait for cacapee to provide the png output.