تحويل CBZ إلى EPUB

CBZ and EPUB: two containers for very different things

A CBZ is nothing more than a ZIP file full of page images, usually JPEG or PNG, named so that they sort in reading order. It carries no text, no table of contents and no metadata beyond an optional ComicInfo.xml. An EPUB is also a ZIP, but one with a defined structure: an OPF manifest listing every file, a reading order called the spine, XHTML chapters with CSS, and a navigation document. Converting a comic therefore means building that structure around the pages: each image becomes a chapter that contains a single picture, the first image becomes the cover, and a navigation list is generated. The reader then treats the comic like any other book, including syncing the reading position and showing it in the library with a cover.

How calibre's comic pipeline processes the pages

Our server runs ebook-convert from calibre inside a container. Its comic input plugin extracts the archive, sorts the images by file name and runs each one through a normalisation step that was designed for e-ink screens: the image is converted to grayscale, trimmed, scaled to the output profile's page size and saved as PNG. The default profile gives pages of 584 by 754 pixels. Wide images are split into two pages. The EPUB output plugin then writes an EPUB 2 package with one XHTML file per page, a title page that shows the cover as scalable SVG, an NCX table of contents and zero page margins. In our measurements a 30-page archive of 65 MB produced a 9.8 MB EPUB in about six seconds; a four-page sample of 60 KB produced a 425 KB EPUB because the colour cover is larger than the downscaled pages.

When to convert and when to keep the archive

• Kindle Paperwhite, Basic, Oasis: convert. The grayscale 6-inch pages are a near-perfect match, and Send to Kindle delivers the EPUB wirelessly.
• Kindle Scribe and large e-readers: the pages are upscaled and look soft; a higher-resolution route is CBZ to PDF, which keeps colour and the same page layout.
• Kobo and PocketBook: open the CBZ directly, no conversion needed.
• Phones and tablets: use a comic app with the CBZ, or convert to PDF for colour. EPUB is only worth it when the comic has to live in a book app such as Apple Books.
• Archiving: always keep the original CBZ. The EPUB is a reduced reading copy, not a replacement.

Related tools

If your archive is a CBR, our CBR to CBZ converter repacks it losslessly first, and CBR to EPUB converts it directly. CBZ to PDF produces a colour PDF with the same reduced page size for tablets and phones. EPUB to CBZ goes the other way and renders an e-book's pages to images. And for loose page images, any ZIP tool creates a CBZ: zip the files with numbered names and rename the archive.