A Low Power Image Sensor Controller and JPEG Encoder IC for Wireless Capsule Endoscopy

In this paper, a low power CMOS image sensor controller and baseline JPEG compression encoder for wireless capsule endoscopy is presented. The proposed JPEG encoder can be integrated into a wireless capsule system to compresses the raster YCbCr 4:2:2 raw image data from image sensor into JPEG format file and then send to external receiver through wireless transmission. To achieve low power and high image compression ratio, the JPEG compression algorithm is optimized for biomedical image compression. The compressed image data are being packed into byte format and DMA can be used to retrieve the JPEG image. The JPEG image compression chip is designed using 0.18-μm CMOS technology. It consumes 1.69 mW under 6 MHz system clock for VGA (640×480) image resolution when compressing at 7.5 frames per second.