TAILIEUCHUNG - EURASIP Journal on Applied Signal Processing 2003:7, 703–712 c 2003 Hindawi Publishing
EURASIP Journal on Applied Signal Processing 2003:7, 703–712 c 2003 Hindawi Publishing Corporation A Vision Chip for Color Segmentation and Pattern Matching Ralph Etienne-Cummings Iguana Robotics, . Box 625, Urbana, IL 61803, USA Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD 21218, USA Email: retienne@ Philippe Pouliquen Iguana Robotics, . Box 62625, Urbana, IL 61803, USA Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD 21218, USA Email: philippe@ M. Anthony Lewis Iguana Robotics, . Box 625, Urbana, IL 61803, USA Email: tlewis@ Received 15 July 2002 and in revised form 20 January 2003 A 128(H) × 64(V) × RGB CMOS imager. | EURASIP Journal on Applied Signal Processing 2003 7 703-712 2003 Hindawi Publishing Corporation A Vision Chip for Color Segmentation and Pattern Matching Ralph Etienne-Cummings Iguana Robotics . Box 625 Urbana IL 61803 USA Department of Electrical and Computer Engineering Johns Hopkins University Baltimore MD 21218 USA Email retienne@ Philippe Pouliquen Iguana Robotics . Box 62625 Urbana IL 61803 USA Department of Electrical and Computer Engineering Johns Hopkins University Baltimore MD 21218 USA Email philippe@ M. Anthony Lewis Iguana Robotics . Box 625 Urbana IL 61803 USA Email tlewis@ Received 15 July 2002 and in revised form 20 January 2003 A 128 H X 64 V X RGB CMOS imager is integrated with region-of-interest selection RGB-to-HSI transformation HSI-based pixel segmentation 36bins X 12bits -HSI histogramming and sum-of-absolute-difference SAD template matching. Thirty-two learned color templates are stored and compared to each image. The chip captures the R G and B images using in-pixel storage before passing the pixel content to a multiplying digital-to-analog converter DAC for white balancing. The DAC can also be used to pipe in images for a PC. The color processing uses a biologically inspired color opponent representation and an analog lookup table to determine the Hue H of each pixel. Saturation S is computed using a loser-take-all circuit. Intensity I is given by the sum of the color components. A histogram of the segments of the image constructed by counting the number of pixels falling into 36 Hue intervals of 10 degrees is stored on a chip and compared against the histograms of new segments using SAD comparisons. We demonstrate color-based image segmentation and object recognition with this chip. Running at 30 ips it uses 1 mW. To our knowledge this is the first chip that integrates imaging color segmentation and color-based object recognition at the focal plane. Keywords and phrases .
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