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Y. Zhao, Y. Lu, J. Zhao, X. Chai, L. Li, Q. Ren; Recognition of Chinese Character Based on Irregular Simulated Phosphene Arrays. Invest. Ophthalmol. Vis. Sci. 2009;50(13):4227.
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© ARVO (1962-2015); The Authors (2016-present)
To investigate the recognition of pixelized Chinese characters based on irregular simulated phosphene arrays in visual prosthesis. In this study, the influences of four parameters (distortion, drop-off rate, pixel-size and grey scale) and the combinations on recognition of Chinese characters were investigated.
Twenty volunteers from 21 to 30 years old with normal or corrected to normal visual acuity of 20/20 were recruited. The trial apparatus included a PC computer with self-developed program, a self-designed light shielding device and a 17-inch CRT screen. The experimental materials were chosen 500 characters according the frequency order from Modern Chinese characters commonly used in the frequency statistics. Each character was formed by 12×12 pixel array according to the former research on recognition of Chinese character. For each parameter, there were different levels to be tested. During fixed time interval, whatever distorted, drop-off, pixel size changed or different grey scales characters were rendered on the screen one by one against black background. In order to reduce the effects of familiarity and adaptability, the testing sequence was in term of descending.
According to the experimental results, it shown that with the increase of distorted level, drop-off rate and pixel size change rate, the recognition decreased considerably. In comparison, the distortion and drop-off changes have more effect than pixel size change on the recognition of Chinese characters. On the contrary, the grey scale change didn’t get obvious decrease. When the combinations of four parameters were used in the test materials, the recognition declined with the increase of different parameter level combination. Moreover, the time of recognition increased obviously.
The results indicate that distortion, drop-off rate and pixel-size have significant impact the recognition for the pixelized Chinese characters. The individual grey scale change hasn’t obvious impact. The four parameter combinations have more impact than individual parameters.
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