ocr fontOptical character recognition, usually abbreviated to OCR, is the mechanical or electronic translation of images typewritten or printed text, captured by a scanner, into machine-editable text.

OCR is a field of research in pattern recognition, artificial intelligence and machine vision. Though academic research in the field continues, the focus on OCR has shifted to implementation of proven techniques. Optical character recognition (using optical techniques such as mirrors and lenses) and digital character recognition (using scanners and computer algorithms) were originally considered separate fields. Because very few applications survive that use true optical techniques, the OCR term has now been broadened to include digital image processing as well.

Early systems required training (the provision of known samples of each character) to read a specific font. “Intelligent” systems with a high degree of recognition accuracy for most fonts are now common. Some systems are even capable of reproducing formatted output that closely approximates the original scanned page including images, columns and other non-textual components.

The accurate recognition of Latin-script, typewritten text is now considered largely a solved problem. Typical accuracy rates exceed 99%, although certain applications demanding even higher accuracy require human review for errors. Other areas–including recognition of hand printing (ICR), cursive handwriting, and printed text in other scripts (especially those with a very large number of characters)–are still the subject of active research.

For more complex recognition problems, intelligent character recognition systems are generally used, using artificial neural networks.