DIGITAL CAMERA WITH NON-UNIFORM IMAGE RESOLUTION

• US 20080088719A1
• Filed: 08/27/2007
• Published: 04/17/2008
• Est. Priority Date: 04/29/2005
• Status: Active Grant

• Current Assignee: Adaptive Imaging Technologies Ltd.
• Original Assignee: Adaptive Imaging Technologies Ltd.
• Inventors: JACOB, Eliezer, Miller, Gideon, Pomerantz, Itzhak
• Granted Patent: US 7,920,182 B2
• Time in Patent Office: Days
• US Class Current: 348/241
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H04N 23/63 by using electronic viewfinders
• CPC Class Codes: H04N 23/661 Transmitting camera control signals through networks, e.g. control via the Internet
• CPC Class Codes: H04N 23/69 Control of means for changing angle of the field of view, e.g. optical zoom objectives or electronic zooming
• CPC Class Codes: H04N 23/698 for achieving an enlarged field of view, e.g. panoramic image capture
• CPC Class Codes: H04N 23/741 by increasing the dynamic range of the image compared to the dynamic range of the electronic image sensors
• CPC Class Codes: H04N 25/50 Control of the SSIS exposure
• CPC Class Codes: H04N 25/621 for the control of blooming
• CPC Class Codes: H04N 25/711 Time delay and integration [TDI] registers; TDI shift registers
• CPC Class Codes: H04N 3/08 having a moving reflector

Abstract

A digital camera includes a sensor adapted to provide a digital representation of a portion of a field of view and an optical system that causes a plurality of locations within the field of view to become incident on the sensor. A pixel correction module adds a bias value to any pixel within the digital representation of a portion of a field of view and multiplies it by a gain factor. A region-of-interest lookup table stores sets of values, each set related to a rectangular region of interest within the field of view. The stored values include bias and gain factors.

Claims

1. A digital camera comprising:

at least one sensor adapted to provide a digital representation of a portion of a field of view;

an optical system causing a plurality of locations within the field of view to become incident on the at least one sensor;

a lookup table, operative to store a plurality of sets of values, each set related to a rectangular region of interest within the field of view, the stored values including values for scanning velocity and time between signal extraction, bias and gain factors, and pixel dilution parameters;

a timing generator and controller, operative to cause the plurality of locations within the field of view to become incident on the at least one sensor at a given velocity and to command video signal extraction from the at least one sensor at a given time, the values for scanning velocity and time between signal extraction being obtained from the lookup table;

a pixel correction module, operative to add a bias factor to any pixel within the digital representation of the portion of a field of view and to further multiply the pixel by a gain factor, the values for bias and gain factors being obtained from the look-up table;

one or more dilutor modules, each operative to select or combine pixels within the digital representation of the portion of a field of view to form a diluted digital image representation, the parameters for pixel dilution being obtained from the from the look-up table.

2. The digital camera of claim 1 wherein the camera is configured such that the lookup table can be modified.

3. The digital camera of claim 1 wherein bias and gain values are automatically calibrated by comparing values of adjacent pixels within a plurality of locations within the field of view under a plurality of lighting conditions.

4. The digital camera of claim 1 wherein the sensitivity of the at least one sensor can be varied for different locations within the field of view.

5. The digital camera of claim 1 wherein reference voltage values are used to correct for differences in bias and gain between sensors.

6. The digital camera of claim 1 wherein the camera is configured such that the lookup table can be modified by a general purpose computer external to the digital camera.

7. The digital camera of claim 1 further comprising a light projector for casting an illumination on a location within the field of view as it becomes incident on the at least one sensor.

8. A digital camera comprising:

a linear array of electro-optical sensor cells;

an opto-mechanical scanner, operative to scan an optical image of the scene across the array;

one or more amplifiers, each receptive to a corresponding signal extracted from the array;

one or more analog-to-digital converters, each receptive to signals from corresponding one or more of the amplifiers and outputting corresponding pixels;

a digital region-of-interest look-up table (ROI LUT), operative to store a plurality of sets of values, each set related to a rectangular region of interest within the image, the stored values including scan parameters, time between signal extractions (TBSE), bias and gain factors, and pixel dilution parameters;

one or more dilutor modules, each operative to select or combine any given ones of the pixels according to corresponding dilution parameters obtained from the ROI LUT, to form a diluted digital image representation;

a timing generator and controller (TGC), operative to effect scanning in a given velocity and to command video signal extraction from the sensor array at given times, all given values being obtained from the ROI LUT for the current scan position

a pixel correction module, operative to add a bias value to any pixel and to multiply it by a gain factor, the bias value and the gain factor being obtained from data in the ROI LUT related to a region of interest that includes a point corresponding to that pixel.

9. A method of acquiring a digital image, the method comprising the steps of:

providing a linear array of a plurality of electro-optical sensor cells, disposed along a first coordinate axis;

scanning an optical image of the scene across the array along a second coordinate axis, orthogonal to the first;

storing a plurality of sets of values, each set related to a corresponding rectangular region within the image, the stored values including digital gain, digital bias, scan velocity, time between signal extractions and pixel dilution parameters;

extracting electrical signals from the sensors array, the time of each extraction being determined by the corresponding time between signal extractions value;

amplifying the signals and converting them to digital representations, structured as pixels;

adding to each pixel a given bias and multiplying it by a given gain, the gain and the bias being determined by the corresponding stored gain and bias values;

diluting pixels according to stored dilution parameters, to form a diluted digital image representation.

10. The method of claim 9, further comprising a light projector for casting an illumination line upon a portion of the field of view as it becomes incident on the linear array.

11. A digital camera comprising:

at least one sensor adapted to provide a digital representation of a portion of a field of view;

an optical system causing a plurality of locations within the field of view to become incident on the at least one sensor;

a pixel correction module, operative to add a bias value to any pixel within the digital representation of a portion of a field of view and to multiply it by a gain factor.

12. The digital camera of claim 11, further comprising:

a lookup table, operative to store a plurality of sets of values, each set related to a rectangular region of interest within the field of view, the stored values including bias and gain factors, wherein the bias and gain factors used by the pixel correction module are obtained from the lookup table.

13. The digital camera of claim 11, further comprising:

a timing generator and controller, operative to cause the plurality of locations within the field of view to become incident on the at least one sensor at a given velocity and to command video signal extraction from the at least one sensor at a given time.

14. The digital camera of claim 13, further comprising:

a lookup table, operative to store a plurality of sets of values, each set related to a rectangular region of interest within the field of view, the stored values including values for scanning velocity and time between signal extraction, wherein the scanning velocity and time between signal extraction of the timing generator and controller are determined by values in the look-up table.

15. The digital camera of claim 11, further comprising:

one or more dilutor modules, each operative to select or combine pixels within the digital representation of a portion of a field of view to form a diluted digital image representation.

16. The digital camera of claim 15, further comprising:

a lookup table, operative to store a plurality of sets of values, each set related to a rectangular region of interest within the field of view, the stored values including values for dilution of pixels, wherein the one or more dilutor modules use the stored values for dilution of pixels to form the diluted digital image representation.

17. A method of acquiring a digital image, the method comprising the steps of:

providing a linear array of a plurality of electro-optical sensor cells;

scanning an optical image of the scene across the array, causing the array to provide a digital representation for each of the electro-optical sensor cells;

storing a plurality of sets of values, each set related to a corresponding rectangular region within the image, the stored values including digital gain, digital bias, scan velocity, time between signal extractions and pixel dilution parameters;

adding to each digital representation a given bias and multiplying it by a given gain, the gain and the bias being determined by the corresponding stored gain and bias values.

18. The method of acquiring a digital image according to claim 17, wherein said step of storing a plurality of sets of values comprises storing said plurality of sets of values in a lookup table.