Evaluation method of digital camera image quality based on Chinese characters testing chart

Based on the use frequency of Chinese characters and its space frequency spectrum analysis, a Chinese characters testing chart is designed for digital camera image-quality evaluation. Under statistical analysis of test results of spatial frequency response (SFR), subjective quality factor (SQF) and the Chinese characters testing chart for 37 different models of digital cameras, the empirical formulas between the just recognizable Chinese characters point size and SFR/SQF are obtained. Verification tests of 10 other digital cameras show that measured SFR/SQF values fall in 95% confidence interval. The Chinese characters testing chart is similar to visual testing chart. This evaluation method has some advantages compared to other methods, such as convenient operation, simplified equipment.