Two different pixel detectors have been fabricated, each of them consisting of an a-Si:H based photodiode layer on top of a crystalline silicon integrated circuit. Both sensors are arranged in a matrix and addressed columnwise, providing parallel readout of the matrix rows or optional random access. One sensor is an a-Si:H detector / x-Si switching transistor combination with 256 × 256 pixels and a pixel size of 100μm × 100μm. The signal transport in the array is examined, demonstrating its capability of very fast information readout. The second sensor, which consists of an array of 32 × 32 pixels on a 5μm PMOS ASIC, performs digital contour extraction. Experimental data on the performance of the intelligent array are also reported.