Signal processing system using recursive radon video transform processor

An apparatus for performing a radon transform on sets of input signals, said input signals including components representing a current pixel value of a line-scanned frame and components representing the Cartesian coordinates of said current pixel, said apparatus comprising:

• a memory for storing said current pixel value components of said input signal at addresses relating to the corresponding ones of said Cartesian coordinates, for thereby producing stored signals, and for reading said stored signals at a predetermined time after their storage, to thereby produce delayed signals;
• and
• at least one window subprocessor unit, said window subprocessor unit comprising
• (a) summing means including first and second noninverting input ports, an inverting input port, and an output port, said first noninverting input port being coupled for receiving said current pixel value component of said input signal, said inverting input port being coupled to said memory for receiving said delayed signals therefrom, and said second noninverting input port being coupled for receiving a signal representing the current value of a radon transform value at a particular value of .rho. and .theta., for subtracting said delayed signals from said current pixel value signals component of said input signals, to produce a difference signal representing the difference between pixel values of a current line of said frame and pixel values of a line of said frame preceding said current line by said predetermined time, and for summing said difference signal with said current value of a radon transform value to thereby produce a summed signal at said output port;
• and
• (b) radon transform generating means including an input port and an output port, said input port being coupled to said output port of said summing means for receiving said summed signal therefrom, for performing a radon transform thereon for said particular value of .theta., to produce said current value of said radon transform value, and for applying said current value of said radon transform value to said second noninverting input port of said summing means.