We present a system-on-chip realization of a CMOS image sensor with on-chip block transformation or spatial convolution capabilities and digital output. The necessary operations are realized with analog current-mode circuits. The digital kernel-coefficients for transformations or convolutions can be set arbitrarily. The prototype implementation is comprised of a 128/spl times/64 pixel CMOS image sensor, signal conditioning, a low-power mixed-signal multiplier array and a dedicated multi-input pipelined A/D converter. The design is scalable up to high sensor resolutions. The prototype was implemented in a standard 0.6 /spl mu/m, double metal, double poly CMOS technology and dissipates 100 mW at 5 V power supply.