Leptonica LibraryThe library supports many operations that are useful onDocument images Natural images Fundamental image processing and image analysis operationsRasterop (aka bitblt) Affine transforms (scaling, translation, rotation, shear) on images of arbitrary pixel depth Binary and grayscale morphology, rank order filters, and convolution Seedfill and connected components Image transformations with changes in pixel depth, both at the same scale and with scale change Pixelwise masking, blending, enhancement, arithmetic ops, etc. Ancillary utilitiesI/O for standard image formats (jpg, png, tiff, bmp, pnm, gif, ps) Utilities to handle arrays of image-related data types (e.g., pixa, boxa, pta) Utilities for stacks, generic arrays, queues, heaps, lists; number and string arrays; etc. Examples of some applications enabled and implementedOctcube-based color quantization (w/ and w/out dithering) Modified median cut color quantization (w/ and w/out dithering) Skew determination of text images Segmentation of page images with mixed text and images jbig2 unsupervised classifier Border representations of 1 bit/pixel images and raster conversion for SVG Postscript wrapping (levels 1, 2) of images for device-independent output Connectivity-preserving thinning and thickening of 1 bit/pixel images Search for least-cost paths on binary and grayscale images Barcode reader for 1D barcodes (very early version as of 1.55) Implementation characteristicsEfficient: image data is packed binary (into 32-bit words); operations on 32-bit data whenever possible Simple: small number of data structures; simplest implementations provided that are efficient Consistent: data allocated on the heap with simple ownership rules; function names usually begin with primary data structure (e.g., pix) Robust: all ptr args checked; extensive use of accessors; exit not permitted Tested: thorough regression tests provided for most basic functions; valgrind tested Ansi C: automatically generated prototype header file Portable: endian-independent; builds in linux, osx, mingw, cygwin, windows Nearly thread-safe: no non-const global vars Documentation: large number of in-line comments; web pages for further background Examples: many programs provided to test and show usage of approx. 1600 functions in the library Open Source Projects that use Leptonicaphp (scripting language for dynamic web pages) tesseract (optical character recognition) jbig2enc (encodes multipage binary image documents with jbig2 compression)