Technology Of Text Extraction From Complicated Background

As a basic Patten Recognition technology, OCR (Optical Character Recognition) technology is widely used in areas such as Computer Input System, Intelligent Transportation System, Security System etc. According to different applications, OCR technology can be divided into General OCR technology and Complicated-Background OCR technology, while the former is mainly used to automatically recognize and input text material into computer system, the latter is mainly used in complicated industry environment such as License Plate Recognition, Container Serial Number Recognition and Train Wagon Serial Number Recognition in Intelligent Transportation System. Complicated-Background OCR technology uses more complicated image processing techniques and pattern recognition technologies than General OCR technology, and it is also one of the front-line sciences in character recognition field.By experiments on LPR(License Plate Recognition) technology, this paper do some researches on Text Extraction Technology in Complicated-Background OCR technology, and proposes a new edge detect method based on PCNN (Pulse-Coupled Neural Networks), and a break noise filtration technique based on Mathematical Morphologic Process.The PCNN was presented to explain the synchronous burst of the neurons in the cat visual cortex by Eckhorn. For its good properties, it has been widely used in image processing and pattern recognition. This paper proposes a Gray Image Edge Detect Method based on PCNN. This method can be used to detect target characters by fetch edges directly from the gray image that was seized in complicated background.When we do a series of preprocessings to the original image, such as Gray Stretch, Threshold Transform etc, in order to extract their characteristics, they often make the strokes of the target characters broken. But normal Morphologic Opening or Closing process will break the strokes much more seriously. By reforming the Morphologic Closing process, this paper proposes a process to eliminate the breaks of target characters.Experiment result shows that the techniques proposed by this paper can detect the edge of target text and eliminate break noise efficiently, and enhance the characteristics of target text.