k2pdfopt: optimizes PDFs for viewing on e-readers

[willus]

Originally Posted by ahmd5800

i found the best result come when i chose 2 column conversion mod just i ask if their any way to make the font size biger or in other word to make the page contain like only 12 lines per page?becase the font size order work just in reflow text not in other conversion mod, and if i chose reflow check the wards become not in that good shape of the source
thank you very very much

If you don't use re-flow, then you are stuck fitting the width of your document to the width of your reading device, and that limits the font size. You must use text re-flow to get to a larger font size. As I said, it would help if you could post your source PDF, or if you don't want to post it publicly, send it to me in a PM.

[ahmd5800]

and this is the sourse file sir

[ahmd5800]

could you find the best setting even if i use text reflow to make it in good shape on kindel the space between lines is not the same and it look bad
this is an image of it

[willus]

Originally Posted by ahmd5800

and this is the sourse file sir

The default options work pretty well for me (along with -r to go right to left). You can increase the size by setting dpi to 400 instead of 300, for example, e.g.

k2pdfopt -r -odpi 400 -vls 1.5 mydoc.pdf

Your margin cropping is a bit aggressive (it will cut off some of the text on some of the pages) and not really necessary--nor are the -ac or -de options since your scan is very clean.

The font varies in size because some of it is from the footnotes, which are typeset in smaller font.

The -vls 1.5 should keep the line spacing more uniform at 1.5x single space.

[ahmd5800]

thanx sir but how can i get red of abnormal space like in the picture

[ahmd5800]

Originally Posted by ahmd5800

thanx sir but how can i get red of abnormal space like in the picture

also if i change the dpi is it ok?
what about if i change the device and chose smaller one (hight and width), is it stel work on my device?
best regard

[willus]

Originally Posted by ahmd5800

also if i change the dpi is it ok?
what about if i change the device and chose smaller one (hight and width), is it stel work on my device?
best regard

Yes--most devices will just fit the PDF page to their screen even if the dimensions or resolution don't exactly match that of the device.

To prevent the large spacing between words you can either turn off full justification like so:

-j 2-

... or you can adjust the word-breaking parameter, e.g. try:

-ws 0.05

K2pdfopt tries to mirror the justification of the source document, which is why full justification is turned on by default for your case.

[Loyd]

Originally Posted by willus

You should not have had to compile 2.51 yourself--there is an OSX binary download on my site. The command-line font size option is -fs, e.g. -fs 12 for 12-point font.

You don't need the -gs option unless you did not compile with MuPDF and are thus forced to use ghostscript. The Mac OSX binaries from my site are compiled with the MuPDF library.

To fully justify the text (no spaces at the end of lines in the converted file) use: -j 0+

To eliminate the artifact on p. 16, remove your -gtr option. It's too high and causing overly aggressive line cutting. The default works fine for your document since there is already plenty of gap between the lines in the source file. You should only need to increase -gtr when the lines in the source file are so close to each other that they slightly overlap in places.

There is no way to change the font with k2pdfopt. That's not part of its functionality. To do that you need to fully convert the PDF to a different type, such as mobi, which often requires a lot of manual editing, or you need the source document that created the PDF.

Also, I think you're over-killing the -dr option. You shouldn't need nearly 3x the resolution of your reading device. All that does is to make the conversion unnecessarily slow and the output file unnecessarily large (in bytes).

So my final recommendation is:
k2pdfopt -dev kp3 -j 0+ -col 1 -mag 1.2 -dr 2 -vls 1.6 -x m.pdf

Converted file attached.

Thank you for your time.

-dev kp3 -j 0+ -col 1 -mag 1.2 -dr 2 -vls 1.6 -x ; it's what I was searching for !

However, when files of the same type contain images the output is, unfortunately, not good (please see the two files attached).

What do you suggest to correct that ?
In advance thank you

[willus]

Originally Posted by Loyd

Thank you for your time.

-dev kp3 -j 0+ -col 1 -mag 1.2 -dr 2 -vls 1.6 -x ; it's what I was searching for !

However, when files of the same type contain images the output is, unfortunately, not good (please see the two files attached).

What do you suggest to correct that ?
In advance thank you

I would suggest allowing two columns for the one figure that has text next to it, but I don't think it will work--the text is too close to the figure. You can add -jfc- to prevent k2pdfopt from trying to interpret the line just underneath a photo as a caption. That should help a little.

[Loyd]

Originally Posted by willus

I would suggest allowing two columns for the one figure that has text next to it, but I don't think it will work--the text is too close to the figure. You can add -jfc- to prevent k2pdfopt from trying to interpret the line just underneath a photo as a caption. That should help a little.

Thank you for your reply.

I tested to increase the number of columns to 2 with this : -dev kp3 -j 0+ -col 2 -mag 1.2 -dr 2 -vls 1.4 -jfc- -x

Unfortunatly the result is not good...

any suggestions are welcome !
Thank you.

[Loyd]

Hello Willius,

I need your help please for these two parts of a scanned book.

Here is a the link : https://workupload.com/file/9ynmQv2L

For the the two parts here are what I used :

-dev kp3 -col 1 -as -c -cmax 1 -s- -dr 2 -mag 1.25 -fc- -vls 1.5 -x

My questions are :

- How to avoid the not correct spacing between lignes (pages 4 and 5 in 1_k2opt and pages 4,5 and 6 in 2_k2opt)?

- How to tell "k2pdfopt" to insert a page break before the begin of each chapter or after un blank page (like in microsoft word) ? My aim is to have the words :" Introduction", "Chapter 3" in the begining of a new page.

Great thanks in advance for your time.

[willus]

Originally Posted by Loyd

Hello Willius,

I need your help please for these two parts of a scanned book.

Here is a the link : https://workupload.com/file/9ynmQv2L

For the the two parts here are what I used :

-dev kp3 -col 1 -as -c -cmax 1 -s- -dr 2 -mag 1.25 -fc- -vls 1.5 -x

My questions are :

- How to avoid the not correct spacing between lignes (pages 4 and 5 in 1_k2opt and pages 4,5 and 6 in 2_k2opt)?

- How to tell "k2pdfopt" to insert a page break before the begin of each chapter or after un blank page (like in microsoft word) ? My aim is to have the words :" Introduction", "Chapter 3" in the begining of a new page.

The autocrop option (-ac) seems to help quite a bit in this case. Try adding that option. For forced page breaks, try the -bpl option or adding a bookmark list (-toclist option). (See the -bp option also.)

[Loyd]

Hello Willius,

I just tested and it's perfect !! Thank you.

I also just need a small clarification about the difference between using :

-idpi, -dr , -fs and -mag.

Fo me it's just like these options are doing the same but a little bit differently ?! What is the best option ? I already read the Help section for each each one, but it's still not clear in my mind.

Thank you

[willus]

Originally Posted by Loyd

Hello Willius,

I just tested and it's perfect !! Thank you.

I also just need a small clarification about the difference between using :

-idpi, -dr , -fs and -mag.

Fo me it's just like these options are doing the same but a little bit differently ?! What is the best option ? I already read the Help section for each each one, but it's still not clear in my mind.

Thank you

Your confusion is understandable, and you are correct--these options are all inter-related. The options have grown over time in order to try and simplify things, but in some ways they have confused things.

-idpi is simply the dpi that the source dpi is rendered internally in k2pdfopt. You shouldn't really need to specify this since it defaults to 2x your output resolution, which should always be sufficient.

-dr is a quick way to increase the resolution of your converted file without changing the page dimensions. You can also do this with -odpi, but the affect of -odpi depends on whether you have specified the output page size in pixels or in inches/cm. If you've specified the output page size in pixels (which is the default), increasing -odpi will cause the output content to magnify. If you've specified the output page size in inches/cm, increasing -odpi will behave the same as -dr -- it will increase the resolution, but not magnify the content. Using -dr will always increase resolution, either way.

-fs is just another way to specify the magnification of the output content relative to the output page size--by using font size rather than dpi if you prefer to do it that way.

-mag is yet another way to increase magnification of the output content. Again, you can achieve the same effect using -odpi, but only if you've specified the output page size in pixels. If you use -mag, it will increase the output content magnification either way you specify the output page size (pixels or inches/cm).

In general, you should leave -idpi set to its default and only ever specify one of -odpi, -fs, or -mag. This will set the size of our output content relative to the output page size. Then you can optionally adjust -dr if the resolution needs adjusting. Equivalently, you could specify only -odpi and the device page size in inches/cm. For instance, the defaults for the latest version of k2pdfopt are Kindle Paperwhite 3, which is 1016 x 1364 pixels at 300 dpi, and therefore 3.39 x 4.55 inches. These two commands are an equivalent way to double the output resolution from the default, keeping the 3.39 x 4.55-inch page size:

k2pdfopt -w 3.39in -h 4.55in -odpi 600 myfile.pdf

k2pdfopt -dr 2 myfile.pdf

Whereas these two commands are an equivalent way to double the output magnification from the default, effectively making the output page 1.7x2.28 inches, so that when it is viewed on the 3.39x4.55-inch screen it is magnified by 2x in each dimension:

k2pdfopt -odpi 600 myfile.pdf

k2pdfopt -mag 2 myfile.pdf

[Loyd]

Originally Posted by willus

Your confusion is understandable, and you are correct--these options are all inter-related. The options have grown over time in order to try and simplify things, but in some ways they have confused things.

-idpi is simply the dpi that the source dpi is rendered internally in k2pdfopt. You shouldn't really need to specify this since it defaults to 2x your output resolution, which should always be sufficient.

-dr is a quick way to increase the resolution of your converted file without changing the page dimensions. You can also do this with -odpi, but the affect of -odpi depends on whether you have specified the output page size in pixels or in inches/cm. If you've specified the output page size in pixels (which is the default), increasing -odpi will cause the output content to magnify. If you've specified the output page size in inches/cm, increasing -odpi will behave the same as -dr -- it will increase the resolution, but not magnify the content. Using -dr will always increase resolution, either way.

-fs is just another way to specify the magnification of the output content relative to the output page size--by using font size rather than dpi if you prefer to do it that way.

-mag is yet another way to increase magnification of the output content. Again, you can achieve the same effect using -odpi, but only if you've specified the output page size in pixels. If you use -mag, it will increase the output content magnification either way you specify the output page size (pixels or inches/cm).

In general, you should leave -idpi set to its default and only ever specify one of -odpi, -fs, or -mag. This will set the size of our output content relative to the output page size. Then you can optionally adjust -dr if the resolution needs adjusting. Equivalently, you could specify only -odpi and the device page size in inches/cm. For instance, the defaults for the latest version of k2pdfopt are Kindle Paperwhite 3, which is 1016 x 1364 pixels at 300 dpi, and therefore 3.39 x 4.55 inches. These two commands are an equivalent way to double the output resolution from the default, keeping the 3.39 x 4.55-inch page size:

k2pdfopt -w 3.39in -h 4.55in -odpi 600 myfile.pdf

k2pdfopt -dr 2 myfile.pdf

Whereas these two commands are an equivalent way to double the output magnification from the default, effectively making the output page 1.7x2.28 inches, so that when it is viewed on the 3.39x4.55-inch screen it is magnified by 2x in each dimension:

k2pdfopt -odpi 600 myfile.pdf

k2pdfopt -mag 2 myfile.pdf

Thanks for taking time to explain in details these options. I see really clear now!

As conversion software, K2pdfopt is very powerful... Thank you for it.