A VLSI architecture for 3-D self-organizing map based color quantization and its FPGA implementation

Color quantization is the process of computing a color palette containing few best colors from a full color image and then associating to each pixel of the image, a color from the palette to yield a color quantized image that is close to the original image. It is of interest in applications such as digital display and image capture. To satisfy real time requirements, it is of vital importance to perform color quantization as fast as possible. This paper presents a novel architecture of a hardware unit for color quantization that is based on Kohonen's self-organizing map. The proposed architecture is of the SIMD type and results in a scheme with linear time complexity (in the size of the image). The architecture has been implemented in Xilinx FPGA and results show that the proposed design achieves high speed taking only a few milliseconds for color quantization of images up to size of 512 × 512 with low area requirement. © 2003 Elsevier Science B.V. All rights reserved.