High performance architecture for image processing

• US 5,262,968 A
• Filed: 06/25/1992
• Issued: 11/16/1993
• Est. Priority Date: 06/25/1992
• Status: Expired due to Fees

• Current Assignee: United States Air Force (Government of the United States of America)
• Original Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Inventors: Coffield, Patrick C.
• Primary Examiner(s): NGUYEN, LONG
• Application Number:
  US07/904,315
• Time in Patent Office: 509 Days
• Field of Search: 364/604, 364/713, 364/822, 382/49
• US Class Current: 708/5
• CPC Class Codes: G06E 1/02 operating upon the order or content of the data handled
• CPC Class Codes: G06J 3/00 Systems for conjoint operation of complete digital and complete analogue computers

Abstract

The logical computer architecture is specifically designed for image processing, and other related computations. The architecture is a data flow concept comprising three tightly coupled components: a spatial configuration processor, a point-wise operation processor, and a accumulation operation processor. The data flow and image processing operations are directed by the control buffer and pipelined to each of the three processing components. The image processing operations are defined by an image algebra capable of describing all common image-to-image transformations. The merit of this architectural design is how elegantly it handles the natural decomposition of algebraic functions into spatially distributed, point-wise operations. The effect of this particular decomposition allows convolution to be computed strictly as a function of the number of elements in the template (mask, filter, etc.) instead of the number of pixels in the image. Thus, a substantial increase in throughput is realized. The logical architecture may take any number of physical forms, including a hybrid electro-optical implementation, and an all digital implementation. The potential utility of this architectural design lies in its ability to control all the arithmetic and logic operations of the image algebra'"'"'s generalized matrix product. This is the most powerful fundamental formulation in the algebra, thus allowing a wide range of applications.

Claims

1. A logical computer architecture for image and signal processing, and other related computations, using a data flow concept for performing operations of an image algebra having an algebraic set of operators;

wherein the architecture comprises three tightly coupled processing components;

a spatial configuration processor (process S), a weighting processor using a point-wise operation (process W), and an accumulation processor (process A), wherein the data flow and image processing operations are directed by a control buffer and pipelined to each of said three processing components;

wherein the spatial configuration processor has an input for an original image and an input for a template, and in operation uses a step-wise discrete convolution of the original input image with each template location, with a unit value assigned to a template element for each convolution, a result of each convolution being a shift of an input image element, providing an output of the spatial configuration processor which is coupled to the weighting processor;

wherein the output of the spatial configuration processor is combined point-wise in the weighting processor, using an appropriate binary associative operator from the algebraic set of operators, with the value of the respective template element, the operation of the weighting processor being an array process execution using said appropriate binary associative operator, the weighting processor having an output coupled to the accumulation processor;

wherein the output of the weighting processor is accumulated point-wise in the accumulation processor, using an appropriate global reduce operator from the algebraic set of operators, the accumulation processor having an accumulator memory which, once the final template element is processed, contains the result of a generalized matrix product defined in the image algebra.

2. A logical computer architecture according to claim 1, wherein the spatial configuration processor is an optical system which comprises a light source providing a coherent collimated light beam which passes through a polarizer to provide a plane wave of polarized coherent light to a first spatial light modulator, said input for an original image being coupled to the first spatial light modulator, to provide a first phase modulated output which is passed to a first Fourier transform lens, light energy from the first Fourier transform lens being passed to a second spatial light modulator, said input for a template being coupled to the second spatial light modulator, to provide a second phase modulated output which is passed to a second Fourier transform lens, output from the second Fourier transform lens being passed through an analyzer which modifies the intensity of the second phase modulated light, with differing levels of intensity being intercepted by a charge coupled device (CCD) array and converted back to digital form, the CCD array having an output which is the output of the spatial configuration processor as a digital electronic signal.

3. A logical computer architecture according to claim 1,

wherein the weighting processor comprises a plurality of weighting processor cells, each of which comprises first, second and third parallel shift registers, and an arithmetic logic unit (ALU) having a multiplier, an adder and a comparator, the first parallel shift register having a scalar input from the control buffer and a parallel output on an n-bit line to the ALU, the second parallel shift register having a digital input connected to the spatial configuration processor and a parallel output on an n-bit line connected to the ALU, and the third parallel shift register having an n-bit parallel input from an output of the ALU and a serial output to the accumulation processor.

4. A logical computer architecture according to claim 3,

wherein the accumulation processor is a parallel processor having a plurality of accumulation processor cells, each of which comprises an accumulator and an arithmetic logic unit (ALU), each ALU of the accumulation processor having a directly connected input from the output of a weighting processor cell, an output connected to the accumulator, and an input from the accumulator.

5. A logical computer architecture according to claim 4, wherein the spatial configuration processor is an optical system which comprises a light source providing a coherent collimated light beam which passes through a polarizer to provide a plane wave of polarized coherent light to a first spatial light modulator, said input for an original image being coupled to the first spatial light modulator, to provide a first phase modulated output which is passed to a first Fourier transform lens, light energy from the first Fourier transform lens being passed to a second spatial light modulator, said input for a template being coupled to the second spatial light modulator, to provide a second phase modulated output which is passed to a second Fourier transform lens, output from the second Fourier transform lens being passed through an analyzer which modifies the intensity of the second phase modulated light, with differing levels of intensity being intercepted by a charge coupled device (CCD) array and converted back to digital form, the CCD array having an output which is the output of the spatial configuration processor as a digital electronic signal.

6. A logical computer architecture according to claim 4, wherein the spatial configuration processor is an acousto-optical analog image translation device which comprises a light source providing a coherent collimated light beam which passes through a liquid crystal light valve, first and second lenses, first and second acousto-optical devices, and third and fourth lenses to a charged coupled device (CCD) array;

said input for an original image being coupled to the liquid crystal light valve, said input for a template being coupled to the first and second acousto-optical devices to provide digital electronic signals as vertical signals to one of the acousto-optical devices and horizontal signals to the other acousto-optical device, the acousto-optical devices being oriented 90 degrees apart;

the CCD array having an output which is the output of the spatial configuration processor to provide an output image in digital form.

7. A logical computer architecture according to claim 4, wherein the spatial configuration processor is an all digital system which comprises a single instruction multiple data array of interconnected parallel shift registers that establishes inter-processor communication at the weighting processor, additional serial connections are made to each parallel shift register from the respective accumulator in each accumulation processor;

said input for an original image being coupled to the array of parallel shift registers from a dedicated bus line, said input for a template being coupled to a correct single instruction shift of the contents of each parallel shift register in the array in cardinal directions north, south, east, and west to provide the appropriate input to the weighting processor.