A Hand-shape Image Acquisition And Processing System Based On DSP

Nowadays, with the rapid development of network IT, the matter of personalidentification information being revealed occurs frequently, as a result, the reliabilityof traditional identification methods are challenged by high-tech crime.Therefore, thebiometric technology utilizing physiological features of human beings, which areunique to human body and not easy to be stolen, has been accepted widely attentionby domestic and foreign related research institutions. Hand-shape recognition, as ausual kind of biometric technology, which is mainly characterized by the geometrydimensions of hand-shape contour, has the advantages of simple algorithm, highrecognition speed and easy to be fused with features of palmprint and vein to achievemulti-modal identification.The theoretical knowledge of hand-shape recognition has been maturing, and thecorresponding identification products also play an significant role in several publicplaces.However,these technology and products are all based on PC,which makes theidentification device has huge volume, high costs and not beneficial to thedevelopment of commercialization. According to the current development trend of thebiometric technology, the embedded hand-shape recognition system, which sets thehand-shape image acquisition, processing and recognition in a group utilizingdedicated image processing chip, such as ARM and DSP, has widespread researchvalue and broad commercial prospects and is the development orientation ofhand-shape recognition products in future.To achieve a hand-shape recognition system based on DSP, firstly, we must try tomake the acquisition and processing algorithm of hand-shape image beingimplemented on DSP.This article has done the following aspects of research aroundthe two issues.（1） Design of hand-shape image acquisition program.We initially choose the digital camera OV7670to acquire hand-shape image and5509A to control the hand-shape image acquisition and processing.However, thischoice can’t satisfy the performance requirements of processing speed and storagecapacity. After consult related technical documentation offered by TI Company, we finally choose DM642and TVP5150A to solve this problem. In this program, TVP5150Ais used to decode the data of hand-shape image from the analog signal offered by CCDand DM642is used to read the data and progress the following treatments.（2） Exploitation of the hand-shape image acquisition driven system.DSP/BIOS, an embedded real-time operating system kernel, which is speciallydesigned by TI Company for its DSP chip, are convenient for users to write multi-taskprograms. On the basis of reading a large amount of knowledge of the DSP/BIOS, wetry our best to make full use of class/mini driver model and API function from the chipdriver development kit (DDK) offered by TI company to design the hand-shape imageacquisition program, by utilizing which we complete the hand-shape imageacquisition.（3） Achievement of hand-shape image processing on DSP.The format of data and the storage method are different in DSP chip, and itsprocessing speed is slower than PC.Therefore, we must do some adjustments andmodifications for the previous algorithm to make sure it can be operated on DSPsystem. In hand-shape image enhancement, this paper uses a3*3fast median filteringalgorithm and uses conventional and lower complex method for thresholdsegmentation and contour extraction. This paper proposes a relative distance-baseddetection method in corner detection stage, which has fewer amounts of computationand higher accuracy. Not only the processing effect but also the real-time quality hasbeen taken into account perfectly in the whole process of the hand-shape imageprocessing.Finally, according to the experimental results, we have made a detailed analysisfrom real-time quality and the CPU processing capacity to illustrate the reliability ofthe hand-shape image acquisition and processing system in this paper.