rescribe.xyz/preproc package

This package contains various image processing methods which are useful for preprocessing page images for OCR. It also contains several commands in the cmd/ directory which can be used to preprocess images directly.

This is a Go package, and can be installed in the standard go way, by running go get rescribe.xyz/preproc/... and documentation can be read with the go doc command or online at https://pkg.go.dev/rescribe.xyz/preproc.

If you just want to install and use the commands, you can get the package with git clone https://git.rescribe.xyz/preproc, and then install them with go install ./... from within the preproc directory.

Commands

There are several commands in the cmd/ directory which are useful in their own right as well as serving as examples of using the package.

• binarize : binarises an image using the sauvola algorithm
• pggraph : creates a graph showing the proportion of black pixels for slices through an image
• preproc : binarises and wipes an image
• preprocmulti : binarises and wipes an image with multiple binarisation ksize values
• wipe : wipes sections of an image that are outside an area detected as content

Bugs

The integral image operations don’t produce exactly the same result as their non-integral image counterparts. The difference is small enough that it has little effect on the output images, but it ought to be identical.

Contributions

Any and all comments, bug reports, patches or pull requests would be very welcomely received. Please email them to nick@rescribe.xyz.

License

This package is licensed under the GPLv3. See the LICENSE file for more details.