Hybrid optical/digital image processor

• US 4,445,141 A
• Filed: 02/04/1980
• Issued: 04/24/1984
• Est. Priority Date: 02/04/1980
• Status: Expired due to Term

• Current Assignee: United States Of America As Represented By The Secretary Of The Army (Government of the United States of America)
• Original Assignee: The United States Of America As Represented By The Secretary Of The Army
• Inventors: Corbett, Francis J., Tuft, Richard A., Benton, John R.
• Primary Examiner(s): ORSINO JR, JOSEPH
• Application Number:
  US06/231,563
• Time in Patent Office: 1,541 Days
• Field of Search: 358/294, 350/162 SF, 350/400, 350/162.12, 350/162.13, 350/162.14, 350/162.15, 364/822
• US Class Current: 358/481
• CPC Class Codes: G06E 3/00 Devices not provided for in group G06E1/00, e.g. for processing analogue or hybrid data

Abstract

A two PROM coherent optical processing system under computer control provides zoom of the input object, rotation of the filter PROM relative to Fourier transform of the coherent light image, serial painting of the spatial filter on the filter PROM using a digitally controlled laser scanner, and greater operator control of the filtered image using a digital video processor and the associated computer.

Claims

1. An optical processor comprising:

a. means for radiating a coherent light image along an optical axis including

(1) input PROM means responsive to light,

(2) means for projecting a non-coherent light image onto said input PROM means; and

(3) means for illuminating said input PROM means with a coherent light;

b. means disposed along said optical axis for providing the Four ier transform of said coherent light image;

c. first linear polarizer means disposed along said optical axis for linear polarizing said Fourier transform;

d. first λ

/4 plate means disposed along said optical axis for circular polarizing the linear polarized Fourier transform;

e. means disposed along said optical axis for spatially filtering said circular polarized Fourier transform;

f. second λ

/4 plate means disposed along said optical axis for converting said circular polarized filtered Fourier transform back to linear polarized form;

g. second linear polarizer means disposed along said optical axis for analyzing said linearly polarized filtered Fourier transform;

h. means for reconstructing said linear polarized filtered Fourier transform to produce a filtered image;

i. optical sensor means for generating an output signal in accordance with said filtered image; and

j. means for rotating about said optical axis said first λ

/4 plate means, said means for spatially filtering and said second λ

/4 plate means.

2. The optical processor as recited in claim 1, wherein said means for illuminating comprises:

a. a source of coherent red light; and

b. means for collimating said coherent red light and for supplying same to said input PROM means.

3. The optical processor as recited in claim 1, wherein said means for reconstructing comprises a reconstruction lens.

4. The optical processor as recited in claim 1, wherein said optical sensor means comprises means for generating a digital signal representative of the total intensity of the filtered image.

5. The optical processor as recited in claim 1, further comprising:

a. digital data processor means under stored program control for generating a rotation signal; and

b. said rotation signal being coupled to said rotating means for controlling the same.

6. The optical processor as recited in claim 1, wherein said means for radiating further comprises means, disposed between said input PROM means and said means for projecting and said means for illuminating, for reflecting said non-coherent light image onto said input PROM means and for transmitting said coherent light to said input PROM means.

7. The optical processor as recited in claim 6, wherein said means for reflecting and for transmitting comprises a dichroic filter.

8. The optical processor as recited in claim 1, wherein said means for projecting comprises:

a. source of non-coherent blue light;

b. means for receiving said non-coherent blue light and for providing said non-coherent blue light image in accordance with an input object; and

c. means for focusing said non-coherent blue light image onto said input PROM means.

9. The optical processor as recited in claim 8, wherein said means for focusing comprises a projection lens.

10. The optical processor as recited in claim 8, wherein said input object is a transparency.

11. The optical processor as recited in claim 8, wherein said means for projecting further comprises means, disposed between said means for providing said non-coherent blue light image and said means for focusing, for zooming said non-coherent blue light image.

12. The optical processor as recited in claim 11, wherein said means for zooming comprises a zoom lens assembly.

13. The optical processor as recited in claim 8, wherein said input object is a photographic negative.

14. The optical processor as recited in claim 13, wherein said source of coherent light comprises a He-Ne laser.

15. The optical processor as recited in claim 1, wherein said means for providing the Fourier transform of said coherent light image comprises a transform lens.

16. The optical processor as recited in claim 15, wherein said transform lens comprises a triplet lens.

17. The optical processor as recited in claim 1, wherein said means for spatially filtering comprises:

a. filter PROM means responsive to blue light; and

b. means for scanning said filter PROM with coherent blue light to produce a spatial filter thereon.

18. The optical processor means as recited in claim 17, wherein said means for scanning comprises:

a. source of coherent blue light;

b. polygon scanner means having a plurality of mirror facets and rotatable about a first axis for reflecting said coherent blue light in a first direction; and

c. galvanometer scanner means having a mirror surface rotatable about a second axis for reflecting said coherent blue light from said polygon scanner means in a second direction and for providing same to said filter PROM.

19. The optical processor as recited in claim 18, wherein said means for scanning further comprises:

a. digital data processor means under stored program control for providing a modulation signal; and

b. acousto-optical modulator means for modulating in accordance with said modulation signal said coherent blue light provided to said polygon scanner means.

20. The optical processor as recited in claim 19, wherein said means for scanning further comprises:

a. substantially constant speed motor for rotating said polygon scanner means about said first axis; and

b. shaft encoder means associated with said motor for generating a shaft encoder signal indicative of the angular position of said polygon scanner means.

21. The optical processor as recited in claim 20, wherein said ditital data processor means comprises interface means responsive to said shaft encoder signal.

22. The optical processor as recited in claim 19, wherein said ditital data processor means comprises:

interface means for generating a galvanometer position signal, and

further comprising means for rotating said mirror surface of said galvanometer scanner means in accordance with said galvnometer position signal.

23. The optical processor as recited in claim 17, wherein said means for scanning comprises means for serially scanning said filter PROM with coherent blue light.

24. The optical processor as recited in claim 23, wherein said source of coherent blue light is a He-Cd laser.

25. The optical processor as recited in claim 23, wherein said means for scanning further comprises:

a. means for spatially filtering and collimating said coherent blue light and for providing same to said polygon scanner means;

b. telescope means for focusing said coherent blue light from said polygon scanner means onto said mirror surface of said galvanometer scanner means; and

c. a flat field scan lens for transmitting said coherent blue light from said galvanometer scanner means to said filter PROM means.

26. The optical processor as recited in claim 17, wherein said means for spatially filtering further comprises means for transmitting to said filter PROM means said coherent blue light from said means for scanning, and for reflecting to said means for reconstructing said linear polarized filtered Fourier transform.

27. The optical processor as recited in claim 26, wherein said means for transmitting and reflecting comprises a dichroic filter.

28. The optical processor as recited in claim 1, wherein said optical sensor means comprises a television camera.

29. The optical processor as recited in claim 28, further comprising means responsive to said output signal for displaying visually said filtered image.

30. The optical processor as recited in claim 29, wherein said means for displaying visually comprises a television monitor.

31. The optical processor as recited in claim 28, further comprising:

a. video processor means responsive to said output signal for generating a display signal; and

b. means for producing a visual display as a function of said display signal.

32. The optical processor as recited in claim 28, further comprising:

a. digital data processing means under stored program control for producing a first signal in accordance with said output signal;

b. video processor means responsive to said first signal for generating a display signal; and

c. means for producing a visual display as a function of said display signal.