MobileRead Forums - View Single Post - Glo [Glo HD] Strange files (parsed extention) in kobo-images directory

davidfor · 10-01-2015, 07:53 PM

Yes, as you discovered the .parsed files are the cover images. For a book, there can be up to four different sizes depending on the firmware version. The recent firmware puts the files in the .kobo-images directory. Under there are two levels of numbered directories with the images in the lowest level. Exactly which directory the images are in is done from a hash based on the image file name. All cover images for a book will have the same name followed by a suffix depending on what it is for. The suffix starts with the "-". The file name is stored in the database against each book.

The example you gave is a the cover for a kepub. Or it could be for a recommendation or other books shown through some of the bookstore functions on the device. The name is a random looking string of letters and numbers. For sideloaded books, it is the full path of the book with certain characters changed to underscores.

Generally, the firmware is good at cleaning up the images as books are removed. This includes when recommendations and other store relate books are removed. In the past, when I found extra cover images, I could find a cause such as a crash or restoring the database (cover images downloaded after the backup was taken are orphaned). For sideloaded books, the only problem I know of is if there is a single quote in the name. In this case, the cover images are not removed when the books are deleted through the firmware. I put a fix in calibre recently to sanitise the file names when sending books so that this didn't happen.

Deleting a book from calibre should remove all the cover images. I have checked this fairly recently, so I am confident it works. If you find a case that it doesn't, then report it.

The image cleanup in the utilities plugin should also work. But, I don't run it often and haven't sat through a full check to make sure for a while. Nothing has changed in the database or the image file naming that would have affected. The cleanup removes all cover images that do not have a reference in the database. That means it will there will be more cover images than actual books on the device. The extras will be for recommendations, related books, wishlist items and previews. If you browse the store, I'm not sure how those covers are handled. Hopefully they are cached in memory while in the store and then discarded.

If there are cover images being left behind by the cleanup or deleting from calibre, then I'd have to look into it. I would of course need some information. A calibre debug log when the cleanup or delete was done would be the starting point. Plus the names of the cover images left behind. And the full path to these files. And there is a good chance I would need a copy of the database to look into why these files were not removed.

If you just want to remove them all, it is reasonably safe to just delete the ".kobo-images" directory or its contents. The cover images for sideloaded books will be regenerated the next time they are needed. I'm not sure what happens for downloaded books. My feeling has always been that the cover images are downloaded rather than generated on the device, but I haven't done much testing of this. If they are generated as needed, everything will be OK. If they are downloaded, you will probably see the default text cover for these books.

10-01-2015, 07:53 PM	#2
davidfor Grand Sorcerer Posts: 24,905 Karma: 47303824 Join Date: Jul 2011 Location: Sydney, Australia Device: Kobo:Touch,Glo, AuraH2O, GloHD,AuraONE, ClaraHD, Libra H2O; tolinoepos	Yes, as you discovered the .parsed files are the cover images. For a book, there can be up to four different sizes depending on the firmware version. The recent firmware puts the files in the .kobo-images directory. Under there are two levels of numbered directories with the images in the lowest level. Exactly which directory the images are in is done from a hash based on the image file name. All cover images for a book will have the same name followed by a suffix depending on what it is for. The suffix starts with the "-". The file name is stored in the database against each book. The example you gave is a the cover for a kepub. Or it could be for a recommendation or other books shown through some of the bookstore functions on the device. The name is a random looking string of letters and numbers. For sideloaded books, it is the full path of the book with certain characters changed to underscores. Generally, the firmware is good at cleaning up the images as books are removed. This includes when recommendations and other store relate books are removed. In the past, when I found extra cover images, I could find a cause such as a crash or restoring the database (cover images downloaded after the backup was taken are orphaned). For sideloaded books, the only problem I know of is if there is a single quote in the name. In this case, the cover images are not removed when the books are deleted through the firmware. I put a fix in calibre recently to sanitise the file names when sending books so that this didn't happen. Deleting a book from calibre should remove all the cover images. I have checked this fairly recently, so I am confident it works. If you find a case that it doesn't, then report it. The image cleanup in the utilities plugin should also work. But, I don't run it often and haven't sat through a full check to make sure for a while. Nothing has changed in the database or the image file naming that would have affected. The cleanup removes all cover images that do not have a reference in the database. That means it will there will be more cover images than actual books on the device. The extras will be for recommendations, related books, wishlist items and previews. If you browse the store, I'm not sure how those covers are handled. Hopefully they are cached in memory while in the store and then discarded. If there are cover images being left behind by the cleanup or deleting from calibre, then I'd have to look into it. I would of course need some information. A calibre debug log when the cleanup or delete was done would be the starting point. Plus the names of the cover images left behind. And the full path to these files. And there is a good chance I would need a copy of the database to look into why these files were not removed. If you just want to remove them all, it is reasonably safe to just delete the ".kobo-images" directory or its contents. The cover images for sideloaded books will be regenerated the next time they are needed. I'm not sure what happens for downloaded books. My feeling has always been that the cover images are downloaded rather than generated on the device, but I haven't done much testing of this. If they are generated as needed, everything will be OK. If they are downloaded, you will probably see the default text cover for these books.