Design And Implementation Of The Banknote's Multi-spectral And High-resolution Image Capture System

To strike the growing economy crime, the police have to collect the characteristic information of counterfeit banknotes which come out nationwide, and analyze them in order to find out the counterfeit crimes that are in the same type. Only in this way the police can strike the counterfeit crime from the source. We collect counterfeit banknotes' information mainly from their multi-spectral and high-resolution image. Common image capture equipment such as cameras can only get banknotes' white-light image, which means they can't capture the image of various spectrums. Although financial instruments such as currency counter can capture banknotes' multi-spectral image, but the images are in low resolution. We can't analyze the details of banknotes' with low-resolution image. Therefore, the study on banknotes' multi-spectral and high-resolution image capture system has great theoretical and practical value.In the view of above situation, this thesis has proposed a general design of banknotes' multi-spectral and high-resolution image capture system based on CIS, FPGA and USB3.0 controller. CIS is controlled by FPGA to capture banknotes' image of various spectrums including white light, infrared light and ultra violet, which is under the resolution of 1200 dpi. Then DDR2 complete the cache of image data under the control of FPGA's IP core. In consideration of high-resolution image's massive data, we design a data transmission module based on USB3.0 controller. In this module, we have completed the GPIF II interface design, firmware design and driver design of the USB3.0 controller and realized the real-time transmission in high speed. We have designed a PC client based on USB3.0 module. The client can receive the image data and convert them to an image through a friendly human-computer communication interface. With the banknotes' image the client will proceed to do the preprocessing. Considering that banknotes are in the different size and there is background noise in the original banknote's image, we proposed a method of banknotes' image standardization based on edge detection and image scaling.The realized banknotes' multi-spectral and high-resolution image capture system based on the design above is examined with RMB. Compared with traditional image capture devices, our system can capture banknotes' image of various spectrums and the image we acquire is in higher quality. Meanwhile our system works stably. The system described in this thesis has been produced commercially, and applied in the ministry of public security.