Wide dynamic range fusion using memory look-up

• US 6,584,235 B1
• Filed: 04/23/1999
• Issued: 06/24/2003
• Est. Priority Date: 04/23/1998
• Status: Expired due to Term

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Kotlyar, Abraham, Fossum, Eric R.
• Primary Examiner(s): Mehta, Bhavesh
• Assistant Examiner(s): Kassa, Yosef
• Application Number:
  US09/299,066
• Time in Patent Office: 1,523 Days
• Field of Search: 382/284, 382/294, 382/291, 382/292, 382/293, 382/295, 382/151, 382/206, 382/209, 382/216, 382/218, 382/219, 345/629, 345/635, 348/584, 348/588
• US Class Current: 382/284
• CPC Class Codes: G06T 1/60 Memory management
• CPC Class Codes: G06T 2200/28 involving image processing hardware
• CPC Class Codes: G06T 5/50 using two or more images, e.g. averaging or subtraction
• CPC Class Codes: H04N 25/589 with different integration times, e.g. short and long exposures
• CPC Class Codes: H04N 25/75 Circuitry for providing, modifying or processing image signals from the pixel array
• CPC Class Codes: H04N 25/767 Horizontal readout lines, multiplexers or registers

Abstract

An image fusion is carried out using a look-up table. The look-up table is addressed by the different kinds of images that will be used to carry out the fusion. Each address in the look-up table contains a precomputed image fusion between the two different kinds of images.

Claims

1. An image processing system, comprising:

an image sensor, including an array of pixels that have units including rows and columns, arranged logically, each pixel including active pixel sensor, including an in-pixel buffer, and in-pixel selector, each pixel also including a photoreceptor which produces an output signal indicative of image information that is applied thereto;

a controller element on the same image substrate with said image sensor, and controlling outputs of said pixels;

first and second register elements, respectively receiving output signals from said pixels, including at least a first register element holding an output of said pixel for a longer period of capture and a second register element holding an output of the same pixel for a shorter period of capture;

a look-up table memory, storing information indicative of an image fusion between different kinds of results for long and short captures, said look-up table memory being addressed with information from said first and second registers and outputting an image fusion result based on contents of said first and second registers.

2. A system as in claim 1, wherein said information comprises a concatenation of the output of said first and second registers on a pixel-by-pixel basis.

3. A device as in claim 2, wherein said look up table memory is on the same substrate with said image sensor.

4. A device as in claim 2, further comprising at least one A/D converter, digitizing outputs of said image sensor.

5. A device as in claim 4, further comprising a first A/D converter digitizing results from said shorter capture, and a second A/D converter, digitizing results from said longer capture.

6. A device as in claim 5, wherein each of said first and second A/D converters includes a single fast A/D converter.

7. A device as in claim 5, wherein each of said first and second A/D converters includes a plurality of a/D converters, each associated with one unit of said array.

8. A system as in claim 1, wherein said look up table has more than two dimensions.

9. A system as in claim 8, wherein one of said dimensions represents a location in the image.

10. A method of determining fusion information, comprising:

obtaining information about two different capture lengths of an image, one which is a shorted capture length and the other of which is a longer capture length;

converting said information into first and second digital groups of bits in first and second register elements;

obtaining a look-up table which is prestored with image fusion information based on said predetermined capture lengths; and

using said first and second digital words to address the information in the look-up table to thereby read-out the information in the look-up table.

11. A method of determining fushion information, comprising:

obtaining information about two different capture lengths of an image, one of which is shorter capture length and the other of which is a longer capture length;

converting said information into first and second digital groups of bits in first and second register elements;

obtaining a look-up table which is prestored with image fushion information based on said predetermined capture lengths; and

using said first and second digital groups to bits to address the information in the look-up table to thereby read-out the information in the look-up table.

12. A system as in claim 11, wherein one of said dimensions represents a location in the image.