APPARATUS AND METHOD FOR ELIMINATING ARTIFACTS IN ACTIVE PIXEL SENSOR (APS) IMAGERS

• US 20120045146A1
• Filed: 10/31/2011
• Published: 02/23/2012
• Est. Priority Date: 03/09/1999
• Status: Active Grant

• Current Assignee: Yibing Michelle Wang
• Original Assignee: Yibing Michelle Wang
• Inventors: Wang, Yibing (Michelle)
• Granted Patent: US 10,063,799 B2
• Time in Patent Office: Days
• US Class Current: 382/274
• CPC Class Codes: H04N 23/76 by influencing the image signals
• CPC Class Codes: H04N 25/627 Detection or reduction of inverted contrast or eclipsing effects
• CPC Class Codes: H04N 25/75 Circuitry for providing, modifying or processing image signals from the pixel array
• CPC Class Codes: H04N 25/78 Readout circuits for addressed sensors, e.g. output amplifiers or A/D converters

Abstract

An active pixel sensor (APS) that includes circuitry to eliminate artifacts in digital images. The APS includes a comparator for comparing a signal level from a pixel to an adjusted saturation voltage to determine if the pixel is saturated. If the pixel is saturated, the signal output from the pixel is replaced with an analog voltage having a maximum value corresponding to a brightest pixel in the image.

Claims

1-15. -15. (canceled)

16. A method comprising:

obtaining a pixel value generated from an imaging pixel;

comparing the pixel value to a reference to determine if the pixel value is at least a nearly saturated value;

replacing the pixel value with a second value if the pixel value is at least a nearly saturated value.

17. The method of claim 16, wherein the pixel value is replaced with a predetermined value that is less than said nearly saturated value.

18. The method of claim 16, wherein the second value signal corresponds to a brightest-possible pixel value.

19. The method of claim 16, wherein the pixel value represents the result of a correlated double sampling of a pixel reset signal value and a pixel incident light signal value.

20. The method of claim 16, wherein the pixel value is a digital pixel value.

21. An imaging system comprising:

a digital circuit for receiving and processing pixel image data, the digital circuit being configured to;

obtain a pixel value generated from an imaging pixel;

compare the pixel value to a reference to determine if the pixel value is at least a nearly saturated value;

replace the pixel value with a second value if the pixel value is at least a nearly saturated value.

22. The imaging system of claim 21, wherein the pixel value is replaced with a predetermined value that is less than said nearly saturated value.

23. The imaging system of claim 21, wherein the second value corresponds to a brightest-possible pixel value.

24. The imaging system of claim 21, wherein the pixel value represents the result of a correlated double sampling of a pixel reset signal value and a pixel incident light signal value.

25. An imaging system comprising:

a digital block adapted to receive image data containing pixel values and output a maximum digital value for each received pixel value which is above a predetermined saturation value.

26. The imaging system of claim 25, wherein the pixel value represents the result of a correlated double sampling of a pixel reset signal value and a pixel incident light signal value.