Camera having distortion correction

• US 20030197124A1
• Filed: 01/17/2003
• Published: 10/23/2003
• Est. Priority Date: 12/26/2000
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Wood, Roland Andrew
• Granted Patent: US 7,365,326 B2
• Time in Patent Office: Days
• US Class Current: 250/332
• CPC Class Codes: G01J 5/02 Constructional details
• CPC Class Codes: G01J 5/0205 Mechanical elements; Supports for optical elements
• CPC Class Codes: G01J 5/023 Particular leg structure or construction or shape; Nanotubes
• CPC Class Codes: G01J 5/025 Interfacing a pyrometer to an external device or network; User interface
• CPC Class Codes: G01J 5/0803 Arrangements for time-dependent attenuation of radiation signals
• CPC Class Codes: G01J 5/0806 Focusing or collimating elements, e.g. lenses or concave mirrors
• CPC Class Codes: G01J 5/20 using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices
• CPC Class Codes: G01J 5/22 Electrical features thereof
• CPC Class Codes: H01L 27/14625 Optical elements or arrangements associated with the device
• CPC Class Codes: H01L 27/14649 Infrared imagers
• CPC Class Codes: H04N 23/55 Optical parts specially adapted for electronic image sensors; Mounting thereof
• CPC Class Codes: H04N 25/61 the noise originating only from the lens unit, e.g. flare, shading, vignetting or "cos4"

Abstract

A lightweight camera is provided that includes a lightweight lens system that has a reduced number of lenses. Reducing the number of lenses produces a lighter camera, but produces a distorted local image. The distorted local image is captured by the lightweight camera, and is preferably transmitted to a remote station. The remote station then performs image processing on the distorted image to remove at least some of the distortion in the image. Preferably, a Massively Parallel Richardson-Lucy (MPRL) algorithm is used to identify and remove distortion from the image. Also, motion, temperature and inter-detector difference distortion is detected and corrected.

Claims

1. A system for electronically capturing an infrared image, comprising:

a lens system;

an array of detectors for capturing a distorted image produced by the lens system and by motion of said array of detectors relative to the infrared image;

a transmitter for transmitting said distorted image; and

a remote station for receiving the distorted image transmitted by said transmitter, said remote station capable of at least partially correcting said distorted image using image processing techniques.

2. A system as in claim 1, wherein said lens system has a single optical element.

3. A system as in claim 1, wherein said lens system includes one or more optical elements that are formed of a substantially infra-red transmissive material.

4. A system as in claim 3, wherein said lens system includes one or more optical elements that are formed primarily of Germanium.

5. A system as in claim 1, wherein said detectors are charged-coupled device CCD) detectors.

6. A system as in claim 1, wherein said detectors are micro-bolometers.

7. A system as in claim 1, wherein said transmitter and said remote station are physically separate from each other, wherein said transmitter is a radio frequency transmitting unit and said remote station is a radio frequency receiving unit.

8. A system as in claim 1, wherein said remote station at least partially corrects said distorted image using a maximum likelihood estimation algorithm.

9. A system as in claim 1, wherein said remote station at least partially corrects said distorted image using a Richardson-Lucy algorithm.

29. The system as in claim 1, wherein:

said lens system, array of detectors and transmitter has a weight less than 15 grams; and

said remote station is situated on the earth.

10. A radiation detector device, comprising:

an array infrared of radiation detector elements having outputs that vary as a function of the amount of infrared radiation striking said detector elements;

a lens having some distortion disposed over said detector array;

a selector for selecting each of said detector elements and outputting a detector output that corresponding to said selected detector element; and

a transmitter for transmitting signals that corresponds to each of said detector outputs to a remote station; and

wherein some distortion is disposed over said detector array due to relative motion between a source of infrared radiation and said detector array.

11. A radiation detector device as in claim 10, wherein said lens has a single optical element.

12. A radiation detector device as in claim 10, wherein said radiation detector device has-no shutter.

13. A radiation detector device as in claim 10, wherein each of the detector outputs is uncompensated for temperature.

14. A radiation detector device as in claim 11, wherein said optical element is formed of Germanium and is supported over said array of radiation detectors by one or more legs.

15. A radiation detector device as in claim 11, further comprising a temperature sensor having an output wherein said temperature sensor output is operably coupled to said transmitter and said transmitter transmits at least one signal corresponding to said temperature sensor output.

30. The radiation detector device as in claim 10, wherein said array of infrared radiation detector elements, lens, selector and transmitter has a weight of less than 15 grams.

16. (Amended) A system for sending a plurality of infrared radiation detector output values and receiving said sent infrared radiation detector output values, comprising:

a remote camera system, the remote camera system having an array of infrared radiation detector elements, each infrared radiation detector element producing an output that is related to the amount of infrared radiation that strikes the corresponding detector element, said remote camera system further including a lens system having distortion disposed over said detector array that may form a distorted image on said detector array, said remote camera system may have motion relative to a source of the infrared radiation that may form a distorted image on said detector arrays, said remote camera system further having a selector for selecting said detector elements and outputting a detector element output, said remote camera system further including a transmitter for transmitting signals that correspond to said detector element outputs; and

a receiving system having a receiver for receiving said transmitted signals, and an image processor for at least partially correcting said distorted image.

17. A system for sending and receiving infrared radiation detector output values as in claim 16, wherein said lens comprises a single optical element.

18. A system for sending and receiving infrared radiation detector output values as in claim 16, wherein said image processor executes a Richardson-Lucy algorithm.

19. A system for sending and receiving infrared radiation detector output values as in claim 16, wherein said remote camera system has no shutter or temperature stabilizer.

20. A system for sending and receiving infrared radiation detector values as in claim 19, wherein said remote camera system includes at least one temperature sensor having an output wherein said temperature sensor output is operably coupled to said transmitter and said transmitter transmits at least one signal corresponding to said temperature sensor output, said receiving system receives said transmitted temperature sensor signal, and compensates said distorted image at least in part as a function of said received temperature sensor signal.

31. (New) A system for sending and receiving radiation detector output values as in claim 16, wherein:

said remote camera is situated in a lightweight micro air vehicle; and

said receiving station is situated on the earth.

21. A method for capturing and processing an image, comprising:

receiving an image using a lens system which may have motion relative to a source of the image causing distortion, the lens system and the motion producing a distorted image;

capturing the distorted image using an array of infrared detectors;

transmitting the captured distorted image;

receiving the distorted image at a remote station; and

processing the distorted image at the remote station to remove at least some distortion in the distorted image.

22. A method for capturing and processing an image as in claim 21, wherein the receiving an image, capturing the distorted image and transmitting the captured distorted image is performed by a device weighing less than 15 grams.

32. A method for capturing and processing an image as in claim 21, wherein:

the lens system and array of detectors are situated in a lightweight micro air vehicle; and

the remote station is situated on the earth.

23. A lightweight camera and system comprising:

a camera comprising;

at least one lens having a nonplanar focal plane;

a substantially planar infrared detector array situated proximate to the nonplanar focal plane of said lens; and

a transmitter connected to said detector array; and

a receiver for receiving wireless signals from said transmitter; and

a processor connected to said receiver; and

wherein;

an image detected by said detector has some nonplanar-to-planar focal plane distortion and said detector has some motion relative to a source of the image resulting in some forward translation of camera blur of the image detected by said detector array; and

said processor reduces the distortion.

24. The camera and system of claim 23, wherein said processor reduces forward translation of camera blur of the image detected by said detector array.

25. The camera and system of claims 24, further comprising:

a temperature sensor situated on said detector array and connected to said transmitter; and

a model having temperature data for the detector array connected to said processor; and

wherein a detector array temperature from said transmitter is adjusted according to temperature data of said model.

26. The camera and system of claim 25 wherein:

said receiver receives individual detector values; and

said processor normalizes the detector values when the individual detectors output different values for the same radiation detected.

27. The camera and system of claim 26, wherein said processor reduces the effects in the image caused by lens defects.

28. The camera and system of claim 27, wherein:

said camera has a weight less than 15 grams; and

said receiver is situated on the ground.

33. A lightweight camera and system comprising:

an IVP camera system;

an accelerometer inertial system;

a transmitter;

supporting electronics connected to said IVP camera system, accelerometer inertial system and transmitter; and

a motherboard; and

wherein said IVP camera system, accelerometer inertial system, transmitter and supporting electronics are situated on said motherboard.

34. The device of claim 33, wherein said motherboard, IVP camera system, accelerometer inertial system, transmitter and supporting electronics in total weigh less than 15 grams.

35. The device of claim 34, further comprising:

receiver electronics;

a motion distortion correction module connected to said receiver electronics; and

a processor connected to said motion distortion correction module; and

wherein said receiver electronics may receive signals from said transmitter.

36. The device of claim 35, further comprising a temperature compensation module connected to said receiver electronics and said processor.

37. The device of claim 36, further comprising an inter-detector difference correction module connected to said receiver electronics and said processor.

38. The device of claim 37, further comprising a lens distortion correction module connected to said receiver electronics and said processor.

39. The device of claim 38, wherein said transmitter and said receiver electronics may be remotely located relative to each other.

40. The device of claim 39, wherein:

said processor may output an image sensed by said IVP camera system; and

the image is generally free from motion, temperature, inter-detector and lens distortion.