Increasing image field of view and frame rate in an imaging apparatus

• US 6,512,541 B2
• Filed: 12/08/1997
• Issued: 01/28/2003
• Est. Priority Date: 12/08/1997
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Dunton, Randy R., Booth, Lawrence A. Jr.
• Primary Examiner(s): Garber, Wendy R.
• Assistant Examiner(s): White, Mitchell
• Application Number:
  US08/986,754
• Publication Number:
  US 20010050712A1
• Time in Patent Office: 1,877 Days
• Field of Search: 348/222, 348/224, 348/229, 348/230, 348/240, 348/239, 348/14, 348/15, 348/18, 348/19, 348/340, 348/135, 348/169, 348/172, 250/203.1, 250/203.6
• US Class Current: 348/230.1
• CPC Class Codes: H04N 23/58 Means for changing the camera field of view without moving the camera body, e.g. nutating or panning of optics or image sensors
• CPC Class Codes: H04N 7/188 Capturing isolated or intermittent images triggered by the occurrence of a predetermined event, e.g. an object reaching a predetermined position signal generation from motion picture films H04N5/253

Abstract

An imaging apparatus that is configurable to operate in at least two modes. One mode is particularly suitable for still image capture, whereas the second mode is suitable for video image capture and other rapid frame rate applications. The image data in the second mode is smaller (lower resolution) than the image data obtained in the first mode. The reduction is accomplished by either digital scaling, cropping, or by a combination of optical scaling and selective readout of sensor signals. The simple digital scaling provides a fixed angular field of view for both modes of operation, while cropping alone gives a smaller field of view. Using the combination of optical scaling and selective sensor signal readout, however, provides a wider field of view for the second mode of operation while at the same time providing lower resolution images, thus improving frame rate in the second mode of operation. The embodiments can be used in a wide range of imaging applications, including digital cameras used for both still image capture and video.

Claims

1. A circuit for use in a digital camera to capture digital images of near and far scenes, comprising:

a signal processing circuit that can be configured to operate in a still capture mode and a video capture node, in the still capture mode the circuit is to process first pixel signals that define an electronic still image of a far scene, the first pixel signals to be generated by a first pixel area of a sensor area of a sensor array in response to the pixel area being illuminated by an optical image of the far scene, and

in the video capture mode, the signal processing circuit is to process second pixel signals that define each of a plurality of electronic images of a near scene, the plurality of electronic images of the near scene to be prepared for transmission to a display device via a computer peripheral bus, the second pixel signals to be generated by a second pixel area of the sensor array in response to the second area being illuminated by a plurality of optical images of the near scene, the optical images of the near scene being smaller than the optical image of the far scene so that the second area is smaller than the first area and the second signals are a subset of the first signals, the circuit is to process the second signals and not others of the first signals in the video capture mode.

2. The circuit of claim 1 wherein

the first signals are digital signals, and

the signal processing circuit includes digital signal and image processing circuitry to form the digital images.

3. The circuit of claim 1 wherein the first signals are analog signals, and the signal processing circuit includes an analog to digital converter to convert the analog signals into digital signals, and the processing of the first and second signals includes converting them from analog into digital form.

4. The circuit of claim 3, wherein the signal processing circuit is to read the second pixel signals but not others of the first pixel signals and then digitally process the second pixel signals but not others of the first pixel signals.

5. The circuit of claim 1 wherein the first signals represent the maximum resolution of the sensor array.

6. A method comprising:

selecting a still capture mode of operation in a digital camera; and

then

processing first pixel signals that define an electronic still image of a far scene, the first pixel signals being generated by a first pixel area of an image sensor array in response to the pixel area being illuminated by an optical image of the far scene; and

then

selecting a video capture mode of operation in the digital camera;

adjusting an optical system coupled to the image sensor array, to form an optical image of a near scene on a second pixel area of the image sensor array that is smaller than the first area, the optical near image being smaller than and having a greater angular field of view than the optical far image; and

then

processing second pixel signals that define each of a plurality of electronic images of the near scene, the second signals being a subset of the first signals and being generated by the second pixel area in response to that pixel area being illuminated by the optical near image; and

further transmitting the plurality of images of the near scene to a display device via a computer peripheral bus, to display motion in the near scene.

7. The method of claim 6 wherein the first signals are digital signals.

8. The method of claim 6 wherein the first signals are analog signals.

9. The method of claim 8, wherein processing second pixel signals comprises:

reading the second pixel signals but not others of the first pixel signals; and

then

digitally processing the second pixel signals but not others of the first pixel signals.

10. The method of claim 6 wherein the first signals represent the maximum resolution of the sensor array.

11. The method of claim 6 wherein the adjusting of the optical system includes moving a lens of the system to change the effective focal length of the optical system.

12. An imaging system comprising:

an image sensor array having a first pixel area and a smaller second pixel area;

an optical system to focus light from a scene onto a focal plane at which the sensor array is disposed, the optical system being adjustable to change its effective field of view of a near scene and a far scene;

means for processing first pixel signals that define an electronic still image of the far scene, the first pixel signals to be generated by the first pixel area in response to the area illuminated by an optical image of a far scene when the system is configured in a still capture mode of operation;

means for processing second pixel signals that define a plurality of images of the near scene, the second signals to be generated by the second pixel area in response to the second area being illuminated by a plurality of optical images of the near scene when the system is configured in a video capture mode of operation, the optical images of the near scene being smaller than the optical image of the far scene, the second signals being a subset of the first signals and said second pixel processing means to process the second signals and not others of the first signals video) capture mode; and

a computer peripheral bus interface to transmit the plurality of electronic images of the near scene to a video display.

13. The system of claim 12 wherein the first signals are digital signals.

14. The system of claim 12 wherein the first signals are analog signals.

15. The system of claim 14, wherein the means for processing second signals is to read the second pixel signals but not others of the first pixel signals and then digitally process the second pixel signals, but not others of the first pixel signals.

16. The system of claim 12 wherein the processing means includes a processor.

17. The system of claim 12 further comprising:

a system controller coupled to configure the processing means to capture near and far images.