Banknote Recognition Image Compensation via Lookup Table
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Solution Overview
Problem
Conventional banknote recognition and verification devices using contact image sensors face inefficiencies due to discrepancies in light-sensitive units, leading to time-consuming image compensation and correction processes that affect the performance of the micro control unit (MCU).
Innovation Solution
A method and device where a programmable logic device, connected to a micro control unit, AD chip, drive circuit, and static random access memory, pre-stores lookup tables for image compensation and correction, allowing the MCU to directly acquire and process pre-calculated correction data, reducing the need for real-time image processing and enhancing system performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the MCU performs image compensation and correction calculations, then the image quality is improved, but the system performance and operation efficiency of the MCU deteriorates
Solution Approach 1:
The patent pre-calculates compensation coefficients for each pixel position of the CIS sensor during the manufacturing or initialization phase, and stores these coefficients in a lookup table in the SRAM. During actual banknote recognition operation, the system only needs to perform table lookup operations rather than complex real-time calculations, thus improving operation efficiency while maintaining image quality correction capability
Solution Approach 2:
The patent replaces the computational mechanism (MCU performing arithmetic calculations) with a memory-based lookup mechanism. The complex mathematical calculations for image compensation are substituted by simple table lookup operations, where the pre-computed correction values are directly retrieved from SRAM based on pixel coordinates, significantly reducing processing time and improving system performance
Data Source
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AI summary
An image compensation correction method and a banknote recognition and detection device. The image compensation correction method is applied to the banknote recognition and detection device. The banknote recognition and detection device comprises: a micro controller (11); a programmable logic device (12) which is connected to the micro controller (11); an AD chip (13), a drive circuit (14) and a static random access memory (15) which are connected to the programmable logic device (12) respectively; and a contact image sensor (16) which is connected to the AD chip (13) and the drive circuit (14) respectively. A compensation correction lookup table is pre-stored in the static random access memory (15), and the programmable logic device (12) can acquire banknote compensation correction data corresponding to a banknote image pixel point by accessing the static random access memory (15), and send same to the micro controller (11). Therefore, the micro controller (11) acquires banknote compensation correction data directly from the programmable logic device (12) rather than performing compensation correction on the obtained banknote image pixel point any more, thereby improving the system performance of the micro controller (11), and thus improving the work efficiency of the banknote recognition and detection device.