FILTER ASSEMBLY AND IMAGE ENHANCEMENT SYSTEM FOR A SURVEILLANCE CAMERA AND METHOD OF USING THE SAME

• US 20080252882A1
• Filed: 04/14/2008
• Published: 10/16/2008
• Est. Priority Date: 04/13/2007
• Status: Abandoned Application

• Current Assignee: John Kesterson
• Original Assignee: John Kesterson
• Inventors: KESTERSON, JOHN
• Application Number:
  US12/102,358
• Publication Number:
  US 20080252882A1
• Time in Patent Office: Days
• US Class Current: 356/300
• CPC Class Codes: G01J 2003/1213 Filters in general, e.g. dichroic, band
• CPC Class Codes: G01J 2003/1243 Pivoting IF or other position variation
• CPC Class Codes: G02B 27/28 for polarising used in stereoscopes G02B30/25
• CPC Class Codes: G02B 5/208 for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation
• CPC Class Codes: H04N 23/55 Optical parts specially adapted for electronic image sensors; Mounting thereof
• CPC Class Codes: H04N 23/75 by influencing optical camera components
• CPC Class Codes: H04N 5/33 Transforming infrared radiation cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20

Abstract

A filter assembly adapted to be used with a camera for selectively controlling the light that reaches the camera'"'"'s aperture. In one embodiment, the filter assembly comprises three filters adapted to be independently moved between a first position wherein they are not in front of the camera'"'"'s aperture and a second position wherein they are in front of the camera'"'"'s aperture. The first and second filters are polarizing filters adapted to block portions of visible light. The third filter is an infrared filter adapted to block infrared light. In addition to moving between its first position and its second position, the second filter is also adapted to rotate up to 360 degrees. The image captured by the camera may be improved using a computer implemented image enhancement system that uses one or more of multi-spectral imaging, deconvolution, edge enhancement, and dynamic range translation.

Claims

1. A filter assembly adapted to selectively prevent certain light waves from passing through an optical device, said filter assembly comprising:

a polarizing filter movable between a first position wherein the polarizing filter does not prevent visible light from passing through the optical device,

and a second position wherein the polarizing filter prevents certain orientations of visible light from passing through the optical device, wherein the polarizing filter is adapted to rotate to change the orientation of visible light that is prevented from passing through the optical device when the polarizing filter is in its second position.

2. The filter assembly of claim 1 wherein the optical device is a camera.

3. The filter assembly of claim 1 wherein the polarizing filter is moved between its first position and its second position by a motor.

4. The filter assembly of claim 1 wherein the polarizing filter is rotated by a motor.

5. A method for removing glare from an image using a filter assembly having a polarizing filter to prevent certain visible light waves from passing through an optical device wherein the polarizing filter is rotatable and movable between a first position wherein the filter does not prevent visible light waves from passing through the optical device and a second position wherein the polarizing filter prevents certain orientations of visible light from passing through the optical device, said method comprising the steps of:

(a) receiving input information about the image;

(b) moving the filter to its second position to prevent certain orientations of visible light from passing through the optical device;

(c) determining the amount of glare contained in the image;

(d) rotating the polarizing filter to acquire a new image having a different amount of glare;

(e) repeating steps (c) and (d) using the new image'"'"'s glare information until the image seen by the optical device contains the desired amount of glare.

6. The method of claim 5 wherein the amount of glare in the image is determined by looking at the variance in the image.

7. The method of claim 5 wherein the input information comprises one or more of the time, the angle of polarized light, the brightness of the image, the amount of glare that is in the image, whether the image is moving, and whether the manual over-ride has been selected.

8. The method of claim 5 wherein the filter assembly further comprises an infrared filter movable between a first position wherein the infrared filter does not prevent infrared light waves from passing through the optical device and a second position wherein the infrared filter prevents infrared light waves from passing through the optical device.

9. The method of claim 8 further comprising the step of moving the infrared filter to its section position.

10. The method of claim 5 wherein the amount that the polarizing filter is rotated is determined based on the image glare information that is relayed to a computer.

11. A filter assembly adapted to selectively prevent certain light waves from passing through an optical device, said filter assembly comprising:

a first polarizing filter movable between a first position wherein the first polarizing filter does not prevent visible light from passing through the optical device, and a second position wherein the first polarizing filter prevents certain orientations of visible light from passing through the optical device;

a second polarizing filter movable between a first position wherein the second polarizing filter does not prevent visible light from passing through the optical device, and a second position wherein the second polarizing filter prevents certain orientations of visible light from passing through the optical device, wherein the second polarizing filter is adapted to rotate to change the orientation of visible light that is prevented from passing through the optical device when the second polarizing filter is in its second position; and

an infrared filter movable between a first position wherein the infrared filter does not prevent infrared light waves from passing through the optical device and a second position wherein the infrared filter prevents infrared light waves from passing through the optical device.

12. The filter assembly of claim 11 wherein the optical device is a camera.

13. The filter assembly of claim 11 wherein the first polarizing filter, second polarizing filter, and infrared filter are moved between their first position and their second position by at least one motor.

14. The filter assembly of claim 11 wherein the second polarizing filter is rotated by a motor.

15. A method for controlling the brightness of an image using a filter assembly having a first and second polarizing filter each adapted to prevent certain light waves from passing through an optical device, wherein the second polarizing filter is rotatable and both filters are adapted to independently move between a first position wherein the filters do not prevent certain light waves from passing through the optical device and a second position wherein the filters prevents certain light waves from passing through the optical device, said method comprising the steps of:

(a) receiving input information about the image;

(b) moving both polarizing filters to their second position in front of the optical device to create an adjustable neutral density filter;

(c) determining the amount of brightness in the image;

(d) rotating the second filter until the brightness is attenuated thereby creating a new image;

(e) repeating steps (c) and (d) using the new image'"'"'s brightness information until the image seen by the optical device has the desired amount of brightness.

16. The method of claim 15 wherein the filter assembly further comprises an infrared filter movable between a first position wherein the infrared filter does not prevent infrared light waves from passing through the optical device and a second position wherein the infrared filter prevents infrared light waves from passing through the optical device.

17. The method of claim 16 further comprising the step of moving the infrared filter to its second position.

18. The method of claim 15 wherein the amount that the second filter is rotated is determined based on image brightness information that is relayed to a computer.

19. The method of claim 15 wherein the distance that the second filter is rotated is determined from look-up tables of pre-known values.

20. A method for viewing infrared images using a filter assembly having a first and second polarizing filter each adapted to prevent certain light waves from passing through an optical device, wherein the second polarizing filter is rotatable and both filters are adapted to independently move between a first position wherein the filters do not prevent certain light waves from passing through the optical device and a second position wherein the filters prevents certain light waves from passing through the optical device, said method comprising the steps of:

(a) receiving input information about the image;

(b) moving both polarizing filters to their second positions; and

(c) rotating the second filter until it is orientated ninety degrees relative to the first filter which creates a neutral density filter that prevents visible light from passing through the optical device yet still allows infrared light to pass through the optical device.

21. A method for enhancing an image as seen through an optical device having at least one filter adapted to prevent certain light waves from passing through the optical device, said method comprising the steps of:

(a) receiving input information about the image;

(b) moving the filter in front of the optical device;

(c) deconvolving the image;

(d) performing multi-spectral imaging on the image;

(e) performing edge enhancement on the image;

(f) performing dynamic range translation on the image.

22. The image enhancement system of claim 21 wherein deconvolving the image further comprises the step of calculating a point spread function.

23. The image enhancement system of claim 21 wherein deconvolving the image further comprises the step of estimating a point spread function.

24. The image enhancement system of claim 21 wherein deconvolving the image further comprises the step of de-blurring the image.

25. The image enhancement system of claim 21 wherein the optical device is a camera.

26. The image enhancement system of claim 25 wherein the camera further comprises a twelve bit chip.

27. The image enhancement system of claim 25 wherein the camera further comprises a sixteen bit chip.