1. A sensing device comprising: an image sensor for capturing images of coded data disposed on a surface when the sensing device is interacted with the surface; a framestore for storing frames of the captured image as image data; subsampling means for subsampling the stored image data to generate subsampled image data; an image processor for processing the subsampled image data to generate processed data based on the coded data sensed during the interaction of the sensing device with the surface; and a second subsampled framestore for storing subsampled image data based on image data from a second framestore, wherein the image processor is integrated on a monolithic integrated circuit, the monolithic integrated circuit including a first subsampled framestore for storing the subsampled image data based on image data from the framestore.