liblept5 binary package in Ubuntu Focal amd64

 Well-tested C library for some basic image processing operations,
 along with a description of the functions and some design methods. A
 full set of affine transformations (translation, shear, rotation,
 scaling) on images of all depths is included, with the exception that
 some of the scaling methods do not work at all depths. There are also
 implementations of binary morphology, grayscale morphology,
 convolution and rank order filters, and applications such as jbig2
 image processing and color quantization. You will also find basic
 utilities for the safe and efficient handling of arrays (of strings,
 numbers, number pairs and image-related geometrical objects), byte
 queues, generic stacks, generic lists, and endian-independent
 indexing into 32-bit arrays.

Source package