k2pdfopt: optimizes PDFs for viewing on e-readers - Page 91

Kuang-che Wu · 02-01-2017, 12:06 AM

Quote:

Originally Posted by willus

Thanks for the suggestion. The small dots are there to force the kindle to fit them in it's view area, otherwise, at least on my old kindle 2, it would try to auto-scale the visible part of the PDF page to its screen. You can try turning them off with -mc-.

I don't mean the dot in the corner. What I am referring is, there are some grey cells in the middle of my grids.

willus · 02-01-2017, 08:55 AM

Quote:

Originally Posted by Kuang-che Wu

I don't mean the dot in the corner. What I am referring is, there are some grey cells in the middle of my grids.

By default, k2pdfopt does some image processing (contrast adjust, gamma adjust, sharpening). The sharpening is probably resulting in those pixel aberrations. To turn off all image processing:
-cmax 1.0 -g 1.0 -s-

Kuang-che Wu · 02-02-2017, 10:41 PM

Feature request for vertical Chinese text.

I know k2pdfopt has option -r (right-to-left), but it is slightly different to what I need.
The default text ordering (for English-like languages) is

Code:

1 2 3
4 5 6
7 8 9

What -r can handle is character right-to-left, line top-to-down

Code:

3 2 1
6 5 4
9 8 7

But for vertical Chinese, the text ordering is character top-to-down, line right to left,

Code:

7 4 1
8 5 2
9 6 3

If applying -r to vertical Chinese text, it may cut text incorrectly. For example,

Code:

7 4 1
8 5 2

Currently, my workaround is -rt 90 -ls. That is, use "-rt 90" to preserve correct text layout analysis and use "-ls" for correct page size. But after k2pdfopt finish, I have to use other utility to rotate the result pdf 180 degree.

p.s. Vertical and horizontal Chinese writing systems are both in use. Usually books with many English text use horizontal Chinese (characters left-to-right, line top-to-down). Literature and novel use vertical Chinese (character top-to-down, line right-to-left).

willus · 02-02-2017, 11:04 PM

Quote:

Originally Posted by Kuang-che Wu

Feature request for vertical Chinese text.

I know k2pdfopt has option -r (right-to-left), but it is slightly different to what I need.
The default text ordering (for English-like languages) is ...
...
Currently, my workaround is -rt 90 -ls. That is, use "-rt 90" to preserve correct text layout analysis and use "-ls" for correct page size. But after k2pdfopt finish, I have to use other utility to rotate the result pdf 180 degree.

p.s. Vertical and horizontal Chinese writing systems are both in use. Usually books with many English text use horizontal Chinese (characters left-to-right, line top-to-down). Literature and novel use vertical Chinese (character top-to-down, line right-to-left).

Actually, I prefer your solution rather than put in special processing for vertical Chinese. Perhaps it could be automated a bit more. I'll think on it. You shouldn't have to use a different utility, though, for the final rotation. k2pdfopt should be able to do all the rotating that you need (-rt option), even if you have to run it in two passes.

Kuang-che Wu · 02-03-2017, 01:50 AM

Quote:

Originally Posted by willus

Actually, I prefer your solution rather than put in special processing for vertical Chinese. Perhaps it could be automated a bit more. I'll think on it. You shouldn't have to use a different utility, though, for the final rotation. k2pdfopt should be able to do all the rotating that you need (-rt option), even if you have to run it in two passes.

FYI, my solution is a little inconvenient

the preview is upside-down.
if used with -cbox/-ibox options, k2pdfopt's GUI let me select the region at 0 degree and I have to swap the values due to -rt 90. I guess other options have similar problems.

Hope this could convince you to modify k2pdfopt

willus · 02-04-2017, 12:26 PM

Quote:

Originally Posted by Kuang-che Wu

FYI, my solution is a little inconvenient

the preview is upside-down.
if used with -cbox/-ibox options, k2pdfopt's GUI let me select the region at 0 degree and I have to swap the values due to -rt 90. I guess other options have similar problems.

Hope this could convince you to modify k2pdfopt

I'd rotate the whole thing before and after you process it, e.g.

Code:

k2pdfopt -mode copy -n -rt 90 srcfile.pdf

... before processing, and ...

Code:

k2pdfopt -mode copy -n -rt -90 processed_file.pdf

... after processing.

dhdurgee · 02-10-2017, 11:44 AM

Is there a way to use the OCR engine in k2pdfopt to produce a text file from a PDF? I would like to create an epub from a PDF and the text file would be a good start. I would also need to use -as to rotate a few pages that are tilted.

Thanks for a great tool.

Dave

willus · 02-10-2017, 05:17 PM

Quote:

Originally Posted by dhdurgee

Is there a way to use the OCR engine in k2pdfopt to produce a text file from a PDF? I would like to create an epub from a PDF and the text file would be a good start. I would also need to use -as to rotate a few pages that are tilted...

Yes, you can use the -ocrout command-line option:

Code:

k2pdfopt -ocrout outfile.txt myfile.pdf

Check my OCR help page. Also be sure to get the latest version (v2.40) which does OCR faster using multi-threading. Finally, you might want to read through my page on PDF conversions for e-books.

dhdurgee · 02-10-2017, 10:59 PM

I gave it a shot with not so great results. First it seg faulted before finishing. Second the output in the text file was garbled.

Looking at your PDF conversions I don't have the new Word and thus have no access to its features. Does Microsoft offer this service online? Could I attach the PDF here and you or someone else could attempt to use word on it? It is a bit over 1MB and I have cropped the article already.

Dave

willus · 02-11-2017, 08:35 AM

Quote:

Originally Posted by dhdurgee

I gave it a shot with not so great results. First it seg faulted before finishing. Second the output in the text file was garbled.

Looking at your PDF conversions I don't have the new Word and thus have no access to its features. Does Microsoft offer this service online? Could I attach the PDF here and you or someone else could attempt to use word on it? It is a bit over 1MB and I have cropped the article already.

Dave

What system are you running? You can post your PDF if it is not copyrighted. I sent you a PM. Also, there is a very recent thread on the PDF forum (just had a new post) discussing PDF to epub conversion.

Bennu · 02-11-2017, 11:48 AM

Thank you for this great software!
If I use

Code:

k2pdfopt -n -wrap- -mode tm

or

Code:

k2pdfopt -wrap- -mode tm

is it possible to rescale the pages to a common width without changing the resolution of the embedded images?
For example I would like the above options plus rescale all pages to a common width of 7 inch.
Right now the unscaled pages look in my pdfreader like in the attachment.

willus · 02-11-2017, 04:43 PM

Quote:

Originally Posted by Bennu

Thank you for this great software!
If I use

Code:

k2pdfopt -n -wrap- -mode tm

or

Code:

k2pdfopt -wrap- -mode tm

is it possible to rescale the pages to a common width without changing the resolution of the embedded images?
For example I would like the above options plus rescale all pages to a common width of 7 inch.
Right now the unscaled pages look in my pdfreader like in the attachment.

This should be possible. You want to keep the output in native mode so as not to change the resolution of your embedded PDF images. I would simply set your device output to 7 inches x XX inches and use -mode fitwidth. I'm not sure if that's exactly what you want. E.g. maybe

Code:

k2pdfopt -h 10in -w 7in -mode fw -ls- mysource.pdf

You could also try it with -mode trim or -mode fitpage instead.
Edit: On second thought, don't use -mode trim--it resets the page size of each page to be whatever the trimmed source content size is.

headshok2002 · 02-12-2017, 11:49 AM

I've just installed this on my MacBook and it's working perfectly. I've been able to convert an 800p book that was previously not readable on an e-reader to something easy and comfortable to read.

Well, on my 6" Kobo Glo.

I do not see the Kobo Aura One in the device menu, though. Is this something that may be added in the future? Or are their known custom settings that work well on the KA1?

Thanks!

willus · 02-12-2017, 03:58 PM

Quote:

Originally Posted by headshok2002

I've just installed this on my MacBook and it's working perfectly. I've been able to convert an 800p book that was previously not readable on an e-reader to something easy and comfortable to read.

Well, on my 6" Kobo Glo.

I do not see the Kobo Aura One in the device menu, though. Is this something that may be added in the future? Or are their known custom settings that work well on the KA1?

Thanks!

If you can post a couple screen shots from your Kobo Aura 1 in this thread, I can tell you what settings to use (and add the KA1 to the built-in device list).

willus · 02-15-2017, 08:33 AM

Quote:

Originally Posted by Kuang-che Wu

...I have a feature suggestion for landscape mode.

...
So if you want to add this mode, you have to collect again the size for device's landscape mode like https://www.mobileread.com/forums/sh....php?p=3013298

...

Kuang-che--can you post your paperwhite screenshots in landscape mode to that thread, using my two PDF files?

02-02-2017, 10:41 PM	#1353
Kuang-che Wu Junior Member Posts: 4 Karma: 29176 Join Date: Jan 2017 Device: kindle paperwhite2	Feature request: vertical text Feature request for vertical Chinese text. I know k2pdfopt has option -r (right-to-left), but it is slightly different to what I need. The default text ordering (for English-like languages) is Code: 1 2 3 4 5 6 7 8 9 What -r can handle is character right-to-left, line top-to-down Code: 3 2 1 6 5 4 9 8 7 But for vertical Chinese, the text ordering is character top-to-down, line right to left, Code: 7 4 1 8 5 2 9 6 3 If applying -r to vertical Chinese text, it may cut text incorrectly. For example, Code: 7 4 1 8 5 2 Currently, my workaround is -rt 90 -ls. That is, use "-rt 90" to preserve correct text layout analysis and use "-ls" for correct page size. But after k2pdfopt finish, I have to use other utility to rotate the result pdf 180 degree. p.s. Vertical and horizontal Chinese writing systems are both in use. Usually books with many English text use horizontal Chinese (characters left-to-right, line top-to-down). Literature and novel use vertical Chinese (character top-to-down, line right-to-left).

02-11-2017, 11:48 AM	#1361
Bennu Junior Member Posts: 1 Karma: 10 Join Date: Feb 2017 Device: kobo aura one	Howto rescale page without changing the resolution of embedded images? Thank you for this great software! If I use Code: k2pdfopt -n -wrap- -mode tm or Code: k2pdfopt -wrap- -mode tm is it possible to rescale the pages to a common width without changing the resolution of the embedded images? For example I would like the above options plus rescale all pages to a common width of 7 inch. Right now the unscaled pages look in my pdfreader like in the attachment. Attached Thumbnails

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02-10-2017, 11:44 AM	#1357
dhdurgee Guru Posts: 880 Karma: 2580688 Join Date: Jun 2010 Device: K3W, PW4	Is there a way to use the OCR engine in k2pdfopt to produce a text file from a PDF? I would like to create an epub from a PDF and the text file would be a good start. I would also need to use -as to rotate a few pages that are tilted. Thanks for a great tool. Dave

02-10-2017, 10:59 PM	#1359
dhdurgee Guru Posts: 880 Karma: 2580688 Join Date: Jun 2010 Device: K3W, PW4	I gave it a shot with not so great results. First it seg faulted before finishing. Second the output in the text file was garbled. Looking at your PDF conversions I don't have the new Word and thus have no access to its features. Does Microsoft offer this service online? Could I attach the PDF here and you or someone else could attempt to use word on it? It is a bit over 1MB and I have cropped the article already. Dave

02-12-2017, 11:49 AM	#1363
headshok2002 Junior Member Posts: 1 Karma: 29176 Join Date: Feb 2017 Device: Kobo Aura One	I've just installed this on my MacBook and it's working perfectly. I've been able to convert an 800p book that was previously not readable on an e-reader to something easy and comfortable to read. Well, on my 6" Kobo Glo. I do not see the Kobo Aura One in the device menu, though. Is this something that may be added in the future? Or are their known custom settings that work well on the KA1? Thanks!

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