A CMOS Image Sensor for Focal-plane Compression using Analog 2-D DCT Circuits and an Adaptive Resolution A/D Converter

Abstract

This paper presents a CMOS image sensor integrating focal-plane compression that uses analog 2-dimensional discrete cosine transform (2-D DCT) circuits and an adaptive resolution A/D converter. The focal-plane compression scheme we propose is useful for high-speed cameras and inexpensive, low-power portable cameras. The PSNR of the reconstructed image using the analog 2-D DCT circuits integrated on the CMOS image sensor is 36.7 dB. The power dissipation of the analog 2-D DCT circuits is about 10.8 mW at 3V for real-time CIF format image coding. The adaptive A/D conversion technique for 2-D DCT coefficients allows us to achieve low-power design throughout the digital video camera system.