Calibre changes size of cover.jpg when copy to new Libary --> see PDF attached
 

Hi folks,

Calibre changes the file size of all covers if copying to a empty library!
Windows 7 32.bit / Calibre 0.7.21

What I did:

1) Create empty library

2) Copy Selection of books into new library

3) Checked filesize of cover.jpg in new library. and compare to old one

I copied approx 1000 + books and filesize changed by +25% also noticeable sometime *.lit files are not copied.

in the PDF you have it with step by step pictures and text

Thanks :help:

Joe

So it didn't change the dimension of the image the the filesize?

hi no it dosent change the dimensions.

im currently still investigating details but in all files the changes are present.

i extracted the DIFF of the image changes and you can see them attached.

if you look at the compare.jpg you will see the Quality settings changing from 75% --> 92% so it seems calibre is doing a preprocessing of the files before rewriting them.

Thanks

Joe

yes all covers are processed. Why is that a problem?

Hi,

basically for two things.

1) why should a copy books to library anyhow do a preprocessing? I was assuming that the copy process is simple a copy and a rename of the directory according to the naming structure.

BOOK TITLE (166) --> BOOK TITLE (23)

2) preprocessing the files and changing quality in jpg's especially when you have a small image increases the filesize without any further info. so I was wondering why my folder size was changing?

Was the whole procedure planned? I mean if there is a good reason why the increase should be there im not against. I just dont see one :-(

thanks for the quick reply.

Joe

It uses the same code path as adding books, which processes images to normalize them and replace transparent backgrounds with white ones.