png to jpg

[gianni_1]

Hi,
with a view to further improving this fantastic program, would it be possible to modify the "Compress images losslessly" menu so that, before compressing images, it converts .png files to .jpg files, since compressing .jpg files is much more effective and, above all, much faster?
Hi and thank you.
Gianni

[kovidgoyal]

That would not be lossless anymore.

[Doitsu]

Originally Posted by gianni_1

Hi,
with a view to further improving this fantastic program, would it be possible to modify the "Compress images losslessly" menu so that, before compressing images, it converts .png files to .jpg files, since compressing .jpg files is much more effective and, above all, much faster?

Shameless plug: my Sigil PNGOptimizer plugin also supports lossy png optimization with pnquant.
(If you don't want to install Sigil and the plugin you can also unzip your epub and use the pnquant binary for your OS.)

[gianni_1]

Originally Posted by kovidgoyal

That would not be lossless anymore.

Hi Kovid,
Yes, that's true, but that's the purpose of my question—to reduce the size of images that are definitely too large. I think it's unacceptable for a text file of about 500 KB to be 54 MB because of .png images. These images are often 300 dpi or higher, while they could be as low as 72 dpi.

Thanks and goodbye,
Gianni

[kovidgoyal]

There you go: https://github.com/kovidgoyal/calibr...a46e99cf121451

[Comfy.n]

Hi Kovid, I have 2 notes about the latest features: Pages recount dialog says 1,000 books per hour. On pretty standard hardware, I finished a large library recount at a 9,250 titles per hour speed - largely EPUB formats but also very heavy PDFs, and all other formats included.

The new Annotation grouping is awesome, but it didnt pick any custom highlight formats.

edit: I meant the 'Restrict to' dropdown.

[kovidgoyal]

Yes, I prefer to err on the side of caution. Speeds can drop on machines with bad antivirus or heavy other loads. 1000 books an hour sets the base expectation. On most ordinary machines you will get 5x-10x that.

[gianni_1]

Originally Posted by kovidgoyal

There you go: https://github.com/kovidgoyal/calibr...a46e99cf121451

Hi Kovid,
Thanks for your reply, but I'd like to ask what I should do with this code. Is it already included in your program, or will it be in the future?
Thanks again, and bye,
Gianni

[DNSB]

It will be included in the next release of calibre after that notification was posted. You can run it before that release by running calibre from source as described in the calibre user manual https://manual.calibre-ebook.com/develop.html.