Image processing device for the real-time processing and recognition of two-dimensional images, and image processing system including at least two series-connected image processing devices of this kind

Claim 1

An image processing device for the real-timeprocessing and recognition of an image consisting of a two-dimensional array of digitized pixels, said device including: a. receiving means (20, 22) for receiving the pixels in order to form therefrom a first bit stream in which each bit represents a pixel; b. a sub-sampling circuit which includes a control input for forming a second bit stream, from the first bit stream, under the control of a pitch-increasing control signal on the control input, and for selectively increasing the pitch of a secondary raster period thereof with respect to a raster of pixels received; c. a buffer which is line-wise fed by the sub-sampling circuit in order to effect temporary storage of the second bit stream and to present the information of a column of pixels in parallel on an output; d. a correlation circuit which is fed by a buffer in order to compare the pixels of a number of successively received columns with corresponding reference pixels, a masking circuit indicating each pixel-wise comparison as being relevant/irrelevant; e. clock means for controlling the sub-sampling circuit, the buffer, the correlation circuit and the selection/processing circuit in mutual synchronism and for controlling the receiving means isochronously with respect thereto, characterized in that the sub-sampling circuit is adapted to adjust the secondary raster period to different values between 1 and a maximum pitch-increasing factor, a selection/processing circuit being connected to the output of the correlation circuit for selectively presenting respective categories of comparison results on a recognition output, which recognition output is suitable for the connection of a further image processing device of this kind as well as for the supply of comparison results to a user device.