Brain Inspired Color Feature Selection Chip

Inspired by the mechanism of visual attentional selection, a color feature selection unit consisting of photoreceptors and an attentional selection circuit (ASC) is presented. The detection and wavelength recognition of trichromatic light are accomplished by the photoreceptors with RGB filters. The ASC, fabricated in a standard CMOS technology, activates the competition among photoreceptors to select the principal color-component feature defined as the attentional focus. The number of focuses and resolution can be changed with a top-down stimulus. Electrical test results show that the ASC can select and interpret the most important color-component feature. In optical tests, the ASC chip-based unit can extract the principal color-component of single-color and dual-color light in real-time to complete color recognition. The percentage ratio between the intensity of stray light relative to the light with maximum intensity is up to 93.58%. And the maximum achievable recognition frame rate is 1 kHz, which is more than one order of magnitude higher than the frequency of the biological vision systems. Besides, the unit's outputs can be transformed into binary codes as labels for color recognition, and the color recognition process does not require the participation of ADC, CPU, and memory, consequently avoiding the von Neumann bottleneck.