An image processing system comprising: a frame based camera configured to periodically provide an image frame covering a field of view of the camera; an event camera having a field of view overlapping the field of view of the frame based camera and configured to provide event information in response to an event indicating a detected change in light intensity at an x,y location within the field of view of the event camera exceeding a threshold; a detector for identifying a region of interest within the overlapping field of view; an accumulator for accumulating event information from a plurality of events occurring during successive event cycles within said region of interest, each event indicating an x,y location within said region of interest, a polarity for a change of detected light intensity incident at said x,y location and an event cycle at which said event occurred, and responsive to an event criterion for the region of interest being met, for generating an image frame for the region of interest from event information accumulated from within the region of interest, at a varying frequency in accordance with the rate of occurrence of events in accordance with an amount of movement within the region of interest; a neural network configured to receive an image frame from the frame based camera and an image frame from the accumulator for the region of interest, the neural network being configured to process each image frame through a plurality of convolutional layers (Block 1...Block 4) to provide a respective set of one or more intermediate images, the neural network being further configured to fuse at least one corresponding pair of intermediate images generated from each of said image frames through an array of fusing cells (22...28), each fusing cell being connected to at least a respective element of each intermediate image and being trained to weight each element from each intermediate image to provide said fused output, said neural network further comprising at least one task network configured to receive said fused output from a final pair of intermediate images and to generate one or more task outputs for the region of interest, wherein said detector is configured to identify the region of interest within said image frame provided by either: said frame based camera; or said event camera. a frame based camera configured to periodically provide an image frame covering a field of view of the camera; an event camera having a field of view overlapping the field of view of the frame based camera and configured to provide event information in response to an event indicating a detected change in light intensity at an x,y location within the field of view of the event camera exceeding a threshold; a detector for identifying a region of interest within the overlapping field of view; an accumulator for accumulating event information from a plurality of events occurring during successive event cycles within said region of interest, each event indicating an x,y location within said region of interest, a polarity for a change of detected light intensity incident at said x,y location and an event cycle at which said event occurred, and responsive to an event criterion for the region of interest being met, for generating an image frame for the region of interest from event information accumulated from within the region of interest, at a varying frequency in accordance with the rate of occurrence of events in accordance with an amount of movement within the region of interest; a neural network configured to receive an image frame from the frame based camera and an image frame from the accumulator for the region of interest, the neural network being configured to process each image frame through a plurality of convolutional layers (Block 1...Block 4) to provide a respective set of one or more intermediate images, the neural network being further configured to fuse at least one corresponding pair of intermediate images generated from each of said image frames through an array of fusing cells (22...28), each fusing cell being connected to at least a respective element of each intermediate image and being trained to weight each element from each intermediate image to provide said fused output, said neural network further comprising at least one task network configured to receive said fused output from a final pair of intermediate images and to generate one or more task outputs for the region of interest, wherein said detector is configured to identify the region of interest within said image frame provided by either: said frame based camera; or said event camera.