Description

Use OCR component to retrieve text from image, for example from scanned paper document.

uses Tesseract OCR engine and Leptonica image processing library

available for Delphi/C++ Builder 5 - XE7 and Lazarus 1.2.6

source code included in full version

royalty free distribution in applications

tesseract-ocr

Tesseract is probably the most accurate open source OCR engine available. Combined with the Leptonica Image Processing Library it can read a wide variety of image formats and convert them to text in over 60 languages. It was one of the top 3 engines in the 1995 UNLV Accuracy test. Between 1995 and 2006 it had little work done on it, but since then it has been improved extensively by Google. It is released under the Apache License 2.0.

https://code.google.com/p/tess...

Leptonica Library

The library supports many operations that are useful on

Document images

Natural images

Fundamental image processing and image analysis operations

Rasterop (aka bitblt)

Affine transforms (scaling, translation, rotation, shear) on images of arbitrary pixel depth

Projective and bilinear transforms

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 utilities

I/O for standard image formats (jpg, png, tiff, bmp, pnm, gif, ps, pdf, webp)

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 implemented

Octcube-based color quantization (w/ and w/out dithering)

Modified median cut color quantization (w/ and w/out dithering)

Skew determination of text images

Adaptive normalization and binarization

Segmentation of page images with mixed text and images

Location of baselines and local skew determination

jbig2 unsupervised classifier

Border representations of 1 bpp images and raster conversion for SVG

Postscript generation (levels 1, 2 and 3) of images for device-independent output

PDF generation (G4, DCT, FLATE) of images for device-independent output

Connectivity-preserving thinning and thickening of 1 bpp images

Image warping (captcha, stereoscopic)

Image dewarping based on content (textlines)

Watershed transform

Greedy splitting of components into rectangles

Location of largest fg or bg rectangles in 1 bpp images

Search for least-cost paths on binary and grayscale images

Barcode reader for 1D barcodes (very early version as of 1.55)

Implementation characteristics

Efficient: 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); simple code patterns throughout

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: ref counting on some structs

Documentation: large number of in-line comments; web pages for further background

Examples: many programs provided to test and show usage of approx. 2200 functions in the library

Additional Information