Title :
A CMOS focal-plane motion sensor with BJT-based retinal smoothing network and modified correlation-based algorithm
Author :
Wu, Chung-Yu ; Huang, Kuan-Hsun
Author_Institution :
Nat. Chiao Tung Univ., Taiwan, Taiwan
fDate :
12/1/2002 12:00:00 AM
Abstract :
This work presents and implements a CMOS real-time focal-plane motion sensor intended to detect the global motion, using the bipolar junction transistor (BJT)-based retinal smoothing network and the modified correlation-based algorithm. In the proposed design, the BJT-based retinal photoreceptor and smoothing network are adopted to acquire images and enhance the contrast of an image while the modified correlation-based algorithm is used in signal processing to determine the velocity and direction of the incident image. The deviations of the calculated velocity and direction for different image patterns are greatly reduced by averaging the correlated output over 16 frame-sampling periods. The proposed motion sensor includes a 32×32 pixel array with a pixel size of 100×100 μm2. The fill factor is 11.6% and the total chip area is 4200×4000 μm2. The DC power consumption is 120 mW at 5 V in the dark. Experimental results have successfully confirmed that the proposed motion sensor can work with different incident images and detect a velocity between 1 pixel/s and 140,000 pixels/s via controlling the frame-sampling period. The minimum detectable displacement in a frame-sampling period is 5 μm. Consequently, the proposed high-performance new motion sensor can be applied to many real-time motion detection systems.
Keywords :
CMOS image sensors; correlation methods; focal planes; image processing equipment; motion estimation; real-time systems; 1024 pixel; 120 mW; 32 pixel; 5 V; 5 micron; BJT-based retinal photoreceptor; BJT-based retinal smoothing network; CMOS focal-plane motion sensor; direction sensor; global motion detection; image contrast enhancement; modified correlation-based algorithm; real-time motion sensor; signal processing; velocity sensor; vision chip; Algorithm design and analysis; CMOS image sensors; Motion detection; Photoreceptors; Pixel; Retina; Sensor arrays; Signal design; Signal processing algorithms; Smoothing methods;
Journal_Title :
Sensors Journal, IEEE
DOI :
10.1109/JSEN.2002.807774