CBconvert
Introduction
CBconvert is a Comic Book converter.
It can convert comics to different formats to fit your various devices.
See more screenshots.
Features
- reads CBR (RAR), CBZ (ZIP), CB7 (7Z), CBT (TAR), PDF, XPS, EPUB, MOBI, DOCX, PPTX and plain directory
- saves processed files in ZIP archive format or TAR
- images can be converted to JPEG, PNG, TIFF, WEBP, AVIF, JXL, or 4-Bit BMP (16 colors) image format
- rotate, adjust brightness/contrast or grayscale images
- resize filters (NearestNeighbor, Box, Linear, MitchellNetravali, CatmullRom, Gaussian, Lanczos)
- export covers from comics
- create thumbnails from covers by FreeDesktop specification
Download
Download the latest binaries from the releases.
Linux Flatpak is available at Flathub.
Using cbconvert in file managers to generate FreeDesktop thumbnails
Copy/install cbconvert cli binary to your PATH, create file ~/.local/share/thumbnailers/cbconvert.thumbnailer
and paste contents from thumbnailer.
This is what it looks like in the PCManFM file manager:
Using command line app
Usage: cbconvert <command> [<flags>] [file1 dir1 ... fileOrDirN]
Commands:
convert
Convert archive or document
--width
Image width (default "0")
--height
Image height (default "0")
--fit
Best fit for required width and height (default "false")
--format
Image format, valid values are jpeg, png, tiff, bmp, webp, avif, jxl (default "jpeg")
--archive
Archive format, valid values are zip, tar (default "zip")
--quality
Image quality (default "75")
--filter
0=NearestNeighbor, 1=Box, 2=Linear, 3=MitchellNetravali, 4=CatmullRom, 6=Gaussian, 7=Lanczos (default "2")
--no-cover
Do not convert the cover image (default "false")
--no-rgb
Do not convert images that have RGB colorspace (default "false")
--no-nonimage
Remove non-image files from the archive (default "false")
--no-convert
Do not transform or convert images (default "false")
--grayscale
Convert images to grayscale (monochromatic) (default "false")
--rotate
Rotate images, valid values are 0, 90, 180, 270 (default "0")
--brightness
Adjust the brightness of the images, must be in the range (-100, 100) (default "0")
--contrast
Adjust the contrast of the images, must be in the range (-100, 100) (default "0")
--suffix
Add suffix to file basename (default "")
--outdir
Output directory (default ".")
--size
Process only files larger than size (in MB) (default "0")
--recursive
Process subdirectories recursively (default "false")
--quiet
Hide console output (default "false")
cover
Extract cover
--width
Image width (default "0")
--height
Image height (default "0")
--fit
Best fit for required width and height (default "false")
--format
Image format, valid values are jpeg, png, tiff, bmp, webp, avif, jxl (default "jpeg")
--quality
Image quality (default "75")
--filter
0=NearestNeighbor, 1=Box, 2=Linear, 3=MitchellNetravali, 4=CatmullRom, 6=Gaussian, 7=Lanczos (default "2")
--outdir
Output directory (default ".")
--size
Process only files larger than size (in MB) (default "0")
--recursive
Process subdirectories recursively (default "false")
--quiet
Hide console output (default "false")
thumbnail
Extract cover thumbnail (freedesktop spec.)
--width
Image width (default "0")
--height
Image height (default "0")
--fit
Best fit for required width and height (default "false")
--filter
0=NearestNeighbor, 1=Box, 2=Linear, 3=MitchellNetravali, 4=CatmullRom, 6=Gaussian, 7=Lanczos (default "2")
--outdir
Output directory (default ".")
--outfile
Output file (default "")
--size
Process only files larger than size (in MB) (default "0")
--recursive
Process subdirectories recursively (default "false")
--quiet
Hide console output (default "false")
meta
CBZ metadata
--cover
Print cover name (default "false")
--comment
Print zip comment (default "false")
--comment-body
Set zip comment (default "")
--file-add
Add file to archive (default "")
--file-remove
Remove file(s) from archive (glob pattern, i.e. *.xml) (default "")
Examples
- Rescale images to 1200px for all supported files found in a directory with a size larger than 60MB:
cbconvert --recursive --width 1200 --size 60 /media/comics/Thorgal/
- Convert all images in pdf to 4bit BMP images and save the result in ~/comics directory:
cbconvert --format bmp --outdir ~/comics /media/comics/Garfield/Garfield_01.pdf
BMP format is a very good choice for black&white pages. Archive size can be smaller 2-3x and the file will be readable by comic readers.
- Extract covers to ~/covers dir for all supported files found in the directory, Lanczos algorithm is used for resizing:
cbconvert cover --outdir ~/covers --filter=7 /media/comics/GrooTheWanderer/
- Convert all images to AVIF format:
cbconvert --format avif --quality 50 --width 1280 --outdir ~/comics /media/comics/Misc/
Quality settings
This table maps quality settings for JPEG to the respective AVIF and WEBP quality settings:
| JPEG quality | 50 | 60 | 70 | 80 |
| AVIF quality | 48 | 51 | 56 | 64 |
| WEBP quality | 55 | 64 | 72 | 82 |
Compile
You must have CGO_ENABLED=1. Note that Go will disable cgo when cross-compiling.
Install to GOBIN (you can point GOBIN to e.g. /usr/local/bin or ~/.local/bin):
go install github.com/gen2brain/cbconvert/cmd/cbconvert@latest
For GUI app, check IUP requirements, and then install:
go install github.com/gen2brain/cbconvert/cmd/cbconvert-gui@latest
Build tags
extlib- use externallibmupdfandlibunarrlibrariespkgconfig- enable pkg-config (used withextlib)