Mobiperl Mobiperl - Perl tools for handling MobiPocket files

[HarryT]

Originally Posted by tompe

There is a flag "--imagerescale 0" which I think will disable all scaling. I checked th code now and from the code without actually testing I draw that conclusion (so i might be wrong...).

It does work. For maps, etc, I get dramatically better quality in the final book by using "--imagerescale 0". That's one of the reasons I wanted to try out "opf2mobi", because in Mobi Creator there's no way to stop the image quality being degraded to get the image under 64k.

[Jellby]

Originally Posted by tompe

There is a flag "--imagerescale 0" which I think will disable all scaling. I checked th code now and from the code without actually testing I draw that conclusion (so i might be wrong...).

I think you are wrong.

In MobiPerl/Util.pm, there's this:

    # pdurrant
    # do not resize large images if the filesize is OK,
    # even if pixel dimensions are large
    if ($filesize < $maxsize and
       ((not $rescale_large_images) || ($x <= $maxwidth and $y <= maxheight))
       and $type ne "PNG"
       and (not defined $scale_factor or $scale_factor == 1.0)) {

       # No transformation has to be done, keep data as is
       ...
    }

That's where I want the program to enter, but the condition is "if $filesize < $maxsize" and other things. I want that even if the filesize is larger, so I had to modify the if and make it:

    if (($filesize < $maxsize and
        ((not $rescale_large_images) || ($x <= $maxwidth and $y <= $maxheight))
        and $type ne "PNG"
        and (not defined $scale_factor or $scale_factor == 1.0)) or (not $rescale_large_images)) {

which is not perfect (it won't touch PNGs, which it should), but it works for me.

[nrapallo]

Originally Posted by Jellby

I think you are wrong.

Jellby, you are right! Not that I'm taking sides...

In my modified html2mobi.pl file that I call from within PDFRead, I sort of disable the automatic Palm image quality reduction which "fits" images within its maxsize (60K) by upping the maxsize to say, triple, that i.e. 180k.

- In MobiPerl/Util.pm, changed bold part:
       my $maxsize = 61000*3;

It is a nice tradeoff between too high quality in .mobi ebooks and inferior .jpg quality artifacts. Obviously this "fix" will break for Palm devices.

[tompe]

This is strange. My memory says that I allowed larger images in term of number of bytes but the code as you point out seems to say something else. I remember being very unwilling allow it but thought I gave in... I might just add a new flag...

[nrapallo]

Originally Posted by tompe

This is strange. My memory says that I allowed larger images in term of number of bytes but the code as you point out seems to say something else. I remember being very unwilling allow it but thought I gave in... I might just add a new flag...

Your memory is correct; you allowed larger images NOT to be resized/rescaled with that flag, but never took care of the secondary .jpg quality reduction to "fit" the Palm maxsize resitriction. At least, this is how *I* remember it.

[HarryT]

Curious. Why is it I wonder, in that case, that my maps, which are >64k in size, look so much better with "imagerescale=0" set? It really is a huge quality difference; text which is "blurry" with the default setting is clear and sharp with the flag set.

[Jellby]

Originally Posted by HarryT

Curious. Why is it I wonder, in that case, that my maps, which are >64k in size, look so much better with "imagerescale=0" set? It really is a huge quality difference; text which is "blurry" with the default setting is clear and sharp with the flag set.

Perhaps they are larger than 640x480 pixels too?

There are these maxima:

Dimensions: 640x480 pixels, it can be disabled with "--imagerescale 0"
Filesize: 61440 bytes, it cannot be disabled with a flag (yet).

If you want to test, run mobi2html on the generated mobi, and you'll see whether the image files were modified or not.

[HarryT]

Originally Posted by Jellby

Perhaps they are larger than 640x480 pixels too?

There are these maxima:

Dimensions: 640x480 pixels, it can be disabled with "--imagerescale 0"
Filesize: 61440 bytes, it cannot be disabled with a flag (yet).

If you want to test, run mobi2html on the generated mobi, and you'll see whether the image files were modified or not.

Thank you, yes, that will be the reason. They are 800x600 images.

[tompe]

Originally Posted by Jellby

Dimensions: 640x480 pixels, it can be disabled with "--imagerescale 0"

I think the bug is fixed in the Cybook so I will change the default to disabled.

[tompe]

Since I have fixed some "bugs" I did a version 0.41 which is available at

https://dev.mobileread.com/trac/mobiperl/

Let me know if I broke something (I have not tested it so much...)

Changes in 0.0.42

• Added flag --allowtts to mobi2mobi
• Added flag --deleteclippinglimit to mobi2mobi
• Enhancement and bug fixes in Opf.pm (goto toc now works and it recognize more cover image tags)
  
• Opf.pm: Removed BOM (byte order mark) from opf file data
  
• --imagerescale default is now 0 (disabled rescaling)
  
• Added flag "--imagemaxbytes n" to specify the maximum size of image data included in the mobi file.

Anybody feel free to build Windows binaries and upload them here...

[Gudy]

Changing user name to 'Anybody' in 5, 4, 3, ... :-D

[tompe]

Originally Posted by Gudy

Changing user name to 'Anybody' in 5, 4, 3, ... :-D

Thanks

[nrapallo]

Originally Posted by Gudy

Changing user name to 'Anybody' in 5, 4, 3, ... :-D

Either that or 'Always'...

Thanks a bunch!!!

[HarryT]

If someone could build Windows binaries I'd be grateful - I don't have PERL installed on my PC .

Edit: Ignore me - I'm overlooking what's right in front of me .

[Jellby]

Originally Posted by tompe

Since I have fixed some "bugs" I did a version 0.41 which is available at

https://dev.mobileread.com/trac/mobiperl/

Let me know if I broke something (I have not tested it so much...)

Changes in 0.0.42
...

Is it 0.0.41 or 0.0.42? And how are we supposed to download it? The download link only gives a changeset zip file, with README and Makefile.

Ah... I see, it's the other link.