Digital camera with non-uniform image resolution

• US 8,068,154 B2
• Filed: 04/29/2005
• Issued: 11/29/2011
• Est. Priority Date: 05/01/2004
• Status: Expired due to Fees

• Current Assignee: Adaptive Imaging Technologies Ltd.
• Original Assignee: Adaptive Imaging Technologies Ltd.
• Inventors: Jacob, Eliezer, Miller, Gideon, Pomerantz, Itzhak
• Primary Examiner(s): Henn; Timothy J
• Assistant Examiner(s): LE, TUAN H
• Application Number:
  US11/117,731
• Publication Number:
  US 20050259158A1
• Time in Patent Office: 2,405 Days
• Field of Search: 348/218.1, 348/294, 348143-146, 348/169, 348/157, 348/166, 348201-202, 348/241, 348/333, 348/208.14, 382/103, 280/236, 356/612
• US Class Current: 348/294
• CPC Class Codes: H04N 25/00 Circuitry of solid-state image sensors [SSIS]; Control thereof
• CPC Class Codes: H04N 25/443 by reading pixels from selected 2D regions of the array, e.g. for windowing or digital zooming
• CPC Class Codes: H04N 25/445 by skipping some contiguous pixels within the read portion of the array
• CPC Class Codes: H04N 25/61 the noise originating only from the lens unit, e.g. flare, shading, vignetting or "cos4"
• CPC Class Codes: H04N 25/76 Addressed sensors, e.g. MOS or CMOS sensors
• CPC Class Codes: H04N 3/1562 for selective scanning, e.g. windowing, zooming

Abstract

The invention provides a system for isolating digital data representative of portions of a field of view. The system, which may be provided in the form of a digital camera, includes an array of sensor cells adapted to provide digital representations corresponding to at least a portion of the field of view, and a selector adapted to isolate a non-uniformly distributed subset of the digital representations provided by the array. The isolation may be performed based upon a set of values programmed in a programmable lookup table. A buffer is provided for holding the isolated digital representations.

Claims

1. A system for isolating digital data representative of a plurality of parts of a field of view, the system comprising:

an array of sensor cells adapted to provide a frame having a plurality of digital representations corresponding to at least a portion of the field of view, the digital representations being distributed uniformly;

a selector adapted to isolate a non-uniformly distributed subset of the plurality of the digital representations provided by the array; and

a buffer for holding simultaneously a single digital image with at least two subsets of the isolated digital representations, the at least two subsets having different resolutions;

wherein the selector isolates the non-uniformly distributed subset according to a determination that is made before the sensor cells provide the digital representations.

2. The system of claim 1, wherein the array of sensor cells is a linear array of sensor cells, and the at least a portion of the field of view is a line of the field of view.

3. The system of claim 2, further comprising a moving element for causing a plurality of lines of the field of view to become incident on the linear array.

4. The system of claim 3, wherein the selector further comprises a line selector adapted to isolate a subset of lines of the field of view.

5. The system of claim 3, wherein the moving element is a rotating mirror.

6. The system of claim 1, further comprising a lookup table reflecting the non-uniformly distributed subset.

7. The system of claim 6, wherein the lookup table can be dynamically modified.

8. The system of claim 7, wherein the lookup table is a binary lookup table, and wherein each of a plurality of entries in the lookup table corresponds to a portion of the field of view.

9. A system for isolating digital data representative of a plurality of parts of a field of view that changes over time, the system comprising:

an array of sensor cells adapted to provide a frame having a plurality of digital representations corresponding to at least a portion of the field of view at a given moment in time, the digital representations being distributed uniformly; and

a programmable selector adapted to isolate a non-uniformly distributed subset of the plurality of the digital representations provided by the array at given moments in time, the isolation being performed based upon a set of values programmed in a programmable lookup table;

wherein the set of values in the programmable lookup table are programmed before the given moment of time that the sensor cells provide the digital representations.

10. The system of claim 9, wherein the array is a linear array and the at least a portion of the field of view is a line of the field of view, the system further comprising:

a rotating mirror for causing a plurality of lines of the field of view to become incident on the linear array;

an encoder for determining the angular position of the mirror;

a line acquirer for activating the selector to isolate the digital representations based upon the programmable lookup table, and for storing the isolated digital representations in a frame buffer at a location corresponding to the angular position of the mirror.

11. The system of claim 10, wherein the programmable lookup table may be dynamically modified.

12. The system of claim 11, further comprising a scene inspector, and wherein the programmable lookup table is dynamically modified upon a signal from the scene inspector.

13. The system of claim 12, wherein the scene inspector can detect a pre-defined feature in the field of view, and the programmable lookup table is dynamically modified to increase resolution in an area of the field of view in which the feature is detected.

14. The system of claim 12, wherein the scene inspector inspects the field of view for the presence of a linearly moving object, and if a linearly moving object is found, detects a rate of speed of the object using at least one subsequent frame buffer representing the field of view.

15. The system of claim 14, wherein the scene inspector estimates the location of a predefined sub-area of the object in a subsequent frame of the field of view, and the programmable lookup table is dynamically modified to increase resolution in an area of the field of view which corresponds to the estimated location of the sub-area in the subsequent frame.

16. The system of claim 15, wherein the linearly moving object is a car, and the predefined sub-are corresponds to a license plate of the car.

17. The system of claim 9, further comprising:

a buffer for receiving and storing the non-uniformly distributed subset of the plurality of the digital representations; and

,

a communication interface for allowing modification of the lookup table and for providing an interface to read data stored in the buffer.

18. The system of claim 17, wherein the communication interface is accessible via a communication link, whereby the plurality of digital representations stored in the buffer can be remotely read and the lookup table can be remotely modified.

19. A method of acquiring a digital image with a non-uniform resolution, the method comprising the steps of:

providing an array comprising uniformly spaced photoelectric sensor cells, the spacing of the sensor cells representing the inverse of a maximum resolution of the array;

exposing the array, causing the array to provide a frame having a digital representation for each of the uniformly spaced photoelectric sensor cells;

selecting from a first region of the array a first subset of the digital representations for the sensor cells within the first region, wherein the first subset has a first average resolution over the first region that is less than the maximum resolution;

selecting from a second region of the array a second subset of the digital representations for the sensor cells within the second region, wherein the second subset has a second average resolution over the second region, and wherein the first average resolution is not equal to the second average resolution;

wherein a single acquired digital image includes the first subset of digital representations and the second subset of digital representations; and

wherein the selecting of the first and second subsets of digital representations is made according to a determination that is made before the array provides the digital representations.

20. A method of acquiring a digital image with a non-uniform resolution using a moving element and a linear array comprising a plurality of uniformly spaced photoelectric sensor cells, the array adapted to provide a digital representation of light incident upon each sensor cell, the method comprising the steps of:

moving the moving element, thereby causing a field of view to become incident on the linear array over time;

acquiring a frame made of a plurality of sets of values from the array while the element is moving and causing the field of view to become incident on the linear array, each set of values comprising a quantity of digital representations which is less than the number of uniformly spaced photoelectric sensor cells of the linear array; and

wherein at least two of the plurality of sets of values from the array comprise digital representations of light incident upon different sets of sensors and the at least two of the plurality of sets of values are elements of the same digital image, which has a non-uniform resolution; and

wherein the sets of values acquired from the array are acquired according to a determination that is made before the acquisition begins.

21. The method of claim 20, 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.

22. The method of claim 20, wherein each of the plurality of sets of values from the array contains the same number of values.

23. The method of claim 22, wherein a lookup table is used in the step of acquiring the plurality of sets of values.

24. A method of displaying the digital image acquired in claim 23 on a digital display having uniformly spaced pixels, the method comprising mapping each value in the digital image on the digital display, thereby causing each value to be displayed on the digital display in a position substantially corresponding to its original position the field of view.

25. The method of displaying a digital image of claim 24, wherein the step of mapping each value in the digital image on the digital display comprises using at least the lookup table to position each value in the digital image on the digital display.

26. The method of claim 20, wherein the moving element is a mirror and the step of moving the element comprises rotating the mirror.

27. The method of claim 26, 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, and wherein the illumination line is reflected on the mirror to be cast upon the portion of the field of view.

28. A method of acquiring a digital image with a non-uniform resolution using a two dimensional array comprising a plurality of uniformly spaced photoelectric sensor cells in each of a plurality of columns and in each of a plurality of rows, the method comprising:

reading from the array a representation of light incident upon each photoelectric sensor cell;

digitizing each of the representations of light to make a digital frame; and

selecting from the digital representations before they are ever stored, a set of values representative of a field of view, the set of values comprising a quantity of digital representations which is less than the number of uniformly spaced photoelectric sensor cells of the two dimensional array,

wherein the set of values contains a digital representation of at least one sensor cell in a given one of the plurality of columns and a given one of the plurality of rows, and wherein the set of values does not contain a digital representation of at least one sensor cell in the given one of the plurality of columns in a different one of the plurality of rows; and

wherein the selecting of the set of values representative of a field of view is made according to a determination that is made before the reading from the array.

29. 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, the plurality of locations being distributed uniformly;

a mask having a programmable value corresponding to each of the plurality of locations, wherein the value may be programmed to be an accept value or a reject value;

a selector adapted to accept a digital representation if the value corresponding to the location is programmed to be an accept value, and to reject a digital representation before it is ever stored if the value corresponding to the location is programmed to be a reject value; and

a buffer for storing each accepted digital representation, wherein the accepted digital representations represent locations within the field of view that are not uniformly spaced from each other;

wherein the values in the mask are programmed before the at least one sensor provides the digital representation.

30. The digital camera of claim 29, further comprising a communication interface for allowing modification of the mask and for providing an interface to read data stored in the buffer.

31. The digital camera of claim 30, wherein the communication interface is accessible via a communication link, whereby the data stored in the buffer can be remotely read and the mask can be remotely modified.

32. The digital camera of claim 29, wherein the optical system comprises at least one imaging lens positioned to image the field of view onto the at least one sensor.