A CMOS Front-End for a Lossy Image Compression Sensor

A CMOS image sensor has been designed to perform the front-end image decomposition in a Prediction-SPIHT image compression scheme. The prediction circuitry based on charge sharing is integrated inside the sensor array to perform a 3-level image decomposition. A CMOS test chip has been prototyped and tested. The test results justify the pixel design and demonstrate that lossy prediction based focal plane image compression can be realized inside the sensor pixel array to achieve a high frame rate but with much less data readout volume. Also, the sensor can be used to achieve comparable compression performance with much lower computational complexity compared to 2D discrete wavelet transform (DWT) based image compression.