Digital camera and method for slowing, delay and/or suspending advanced processing during low battery conditions to conserve battery charge

• US 20040257462A1
• Filed: 06/17/2003
• Published: 12/23/2004
• Est. Priority Date: 06/17/2003
• Status: Abandoned Application

• Current Assignee: Hewlett-Packard Development Co. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Co. (HP Inc.)
• Inventors: Goris, Andrew C., Sobol, Robert E., Bianchi, Mark J.
• Application Number:
  US10/462,961
• Publication Number:
  US 20040257462A1
• Time in Patent Office: Days
• US Class Current: 348/372
• CPC Class Codes: H04N 23/631 Graphical user interfaces [GUI] specially adapted for controlling image capture or setting capture parameters
• CPC Class Codes: H04N 23/651 for reducing power consumption by affecting camera operations, e.g. sleep mode, hibernation mode or power off of selective parts of the camera

Abstract

An electronic camera has a battery, a battery charge-monitor circuit for monitoring battery charge, an embedded image-processing system, and a nonvolatile memory coupled to the embedded image-processing system for recording compressed images. The camera is capable of performing an initial compression and of performing advanced processing of images. The camera is capable of saving partially processed and/or intermediate images on nonvolatile memory, and suspending advanced processing, when the battery charge-monitor circuit detects that battery charge is less than a minimum or a reserve level. In an alternative embodiment, the camera is capable of reducing a clock rate at which advanced processing is performed to conserve battery charge.

Claims

1. An electronic camera comprising:

a battery;

a lens and image sensor for capturing images;

a battery charge-monitor for monitoring battery charge;

an embedded image-processing system, coupled to the battery and capable of being powered by the battery, for processing and compressing captured images;

a management processor coupled to the battery charge-monitor;

a nonvolatile memory, coupled to the embedded image-processing system, for recording compressed images;

wherein the embedded image-processing system has firmware for performing an initial compression and for performing advanced processing of images; and

wherein the image processing system has firmware for saving intermediate results of advanced processing on nonvolatile memory and suspending advanced processing when the battery charge-monitor circuit detects that battery charge is less than a reserve level.

2. The electronic camera of claim 1, wherein the camera stores the intermediate results in nonremovable nonvolatile memory, and wherein the camera stores compressed images in removable nonvolatile memory.

3. The electronic camera of claim 1, wherein the image processing system has firmware for saving intermediate results on nonvolatile memory periodically.

4. The electronic camera of claim 3, wherein the camera is capable of resuming advanced processing upon detecting an event selected from the group of events consisting of battery replacement and connection of external power to the camera.

5. The electronic camera of claim 3, wherein the image processing system performs advanced processing at a different image processing system clock rate than a clock rate used for initial compression.

6. The electronic camera of claim 3, wherein the image processing system has a clock rate used for advanced processing selected according to whether the camera is connected to external power.

7. A method of conserving power in a digital camera comprising the steps of:

capturing an image;

performing initial compression on the image in an embedded image processing system, and saving an initially compressed image in a nonvolatile memory;

decreasing a clock rate of the embedded image processing system to reduce a load current on a battery that powers the camera;

performing advanced processing on the image;

monitoring a charge level of the battery and, upon battery charge level dropping below a reserve charge level, saving intermediate results in a nonvolatile memory.

8. The method of claim 7, wherein the reserve charge level is set to a level that allows the camera to capture and perform initial compression on at least one additional image before the battery charge level drops below a minimum charge level.

9. The method of claim 7, further comprising the step of resuming advanced processing upon an event selected from the group consisting of detecting insertion of charged batteries into the camera and detecting connection of external power to the camera.

10. The method of claim 7, wherein the reserve level is adjustable by a user.

11. The method of claim 7, further comprising the step of holding raw image data in memory until an event selected from the group consisting of a timeout and an advanced processing request by a user.

12. The method of claim 11, further comprising the steps of determining if battery charge is below a reserve level and, if battery charge is below the reserve level, saving raw image data in nonvolatile memory to permit later advanced processing.

13. The method of claim 11, wherein the advanced processing is image processing selected from the group comprising blur reduction, local contrast enhancement, recompression of the image with a different compression algorithm than that used for initial compression, automatic photomosaic creation, and blending of over and under exposed images.

14. An electronic camera comprising:

a battery;

a battery charge-monitor circuit for monitoring battery charge;

an embedded image-processing system powered by the battery;

a nonvolatile memory, coupled to the embedded image-processing systemfor storing compressed images;

wherein the embedded image-processing system has firmware for performing an initial compression and for performing advanced processing of images;

wherein the image processing system embedded image-processing system has firmware for saving intermediate results on nonvolatile memory and suspending advanced processing when the battery charge-monitor circuit detects that battery charge is less than a reserve level; and

wherein the reserve level is chosen to permit the camera to capture and perform initial compression of at least one additional image before the battery charge drops below a minimum charge level.

15. The electronic camera of claim 14, wherein the camera performs advanced processing at a slower image processing system clock rate than used for initial compression.

16. The electronic camera of claim 14, wherein the advanced processing is image processing selected from the group comprising blur reduction, local contrast enhancement, recompression of the image with a different compression algorithm than that used for initial compression, automatic photomosaic creation, and blending of over and under exposed images.

17. The electronic camera of claim 14, wherein the camera holds raw image data in memory after initial compression until an event selected from the group consisting of a timeout, a new image capture trigger, and an advanced processing request by a user.