System and method for power reduction when decompressing video streams for interferometric modulator displays

• US 20070147688A1
• Filed: 12/22/2005
• Published: 06/28/2007
• Est. Priority Date: 12/22/2005
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Mathew, Mithran
• Granted Patent: US 8,391,630 B2
• Time in Patent Office: Days
• US Class Current: 382/232
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 3/20 for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
• CPC Class Codes: G09G 3/3466 based on interferometric effect

Abstract

A system and method for processing image data to be displayed on a display device, where the display device requires more power to be driven to display image data comprising particular spatial frequencies in one dimension than to be driven to display image data comprising the particular spatial frequencies in a second dimension. The method includes receiving image data and filtering the received image data such that the image data at particular spatial frequencies in a first dimension are attenuated more than the image data at particular spatial frequencies in a second dimension.

Claims

1. A method for processing image data to be displayed on a display device, the display device requiring more power to be driven to display image data comprising particular spatial frequencies in one dimension than to be driven to display image data comprising the particular spatial frequencies in a second dimension, the method comprising:

receiving image data; and

filtering the received image data such that the image data at particular spatial frequencies in a first dimension are attenuated more than the image data at particular spatial frequencies in a second dimension.

2. The method of claim 1, further comprising displaying the filtered image data on the display device.

3. The method of claim 1, wherein the filtering comprises spatial domain filtering.

4. The method of claim 1, wherein the filtering comprises filtering in a transformed domain.

5. The method of claim 4, wherein the received image data is in the transformed domain, the method further comprising:

inverse transforming the filtered image data, thereby resulting in spatial domain image data.

6. The method of claim 1, wherein the filtering comprises low pass filtering wherein lower spatial frequencies remain substantially unchanged after filtering.

7. The method of claim 1, further comprising:

estimating a power required to drive the display device to display the received image data; and

performing the filtering in response to the estimating.

8. The method of claim 4, wherein the transformed domain is one of a discrete Fourier transformed domain, a discrete cosine transformed domain, a Hadamard transformed domain, a discrete wavelet transformed domain, a discrete sine transformed domain, a Haar transformed domain, a slant transformed domain, a Karhunen-Loeve transformed domain and an H.264 integer transformed domain.

9. The method of claim 1, further comprising:

estimating a remaining lifetime of a power supply; and

performing the filtering in response to the estimating.

10. The method of claim 1, further comprising:

estimating a remaining lifetime of a power supply; and

performing the filtering with a first parameter set if the estimated remaining lifetime is below a first threshold, and performing the filtering with a second parameter set if the estimated remaining lifetime is below a second threshold, wherein the first threshold is larger than the second threshold, and wherein the first parameter set results in less attenuation of the particular frequencies than the second parameter set.

11. An apparatus for displaying image data, comprising:

a display device, the display device requiring more power to be driven to display image data comprising particular spatial frequencies in a first dimension than to be driven to display image data comprising the particular spatial frequencies in a second dimension;

a processor configured to receive image data and to filter the image data, the filtering being such that the image data at particular spatial frequencies in the first dimension are attenuated more than the image data at particular spatial frequencies in the second dimension; and

at least one driver circuit configured to communicate with the processor and to drive the display device, the driver circuit further configured to provide the filtered image data to the display device.

12. The apparatus of claim 11, wherein the filtering is done in a spatial domain.

13. The apparatus of claim 11, wherein the filtering is done in a transformed domain.

14. The method of claim 13, wherein the processor is further configured to receive image data in the transformed domain, and to inverse transform the filtered image data, thereby resulting in the filtered image data being in the spatial domain.

15. The apparatus of claim 11, further comprising:

a power supply;

the processor further configured to receive or produce an estimated remaining lifetime of the power supply; and

wherein the processor is further configured to filter the image data if the estimated remaining lifetime is below a threshold.

16. The apparatus of claim 11, wherein the display comprises an array of interferometric modulators.

17. The apparatus of claim 11, wherein the processor is further configured to produce an estimate of power required to drive the display device to display the image data and to filter the image data in response to the estimated power.

18. The apparatus of claim 11, wherein the process is further configured to produce an estimate of power required to drive the display device to display the image data, to compare the estimated power to a threshold and to filter the image data if the estimated power is above the threshold.

19. The apparatus of claim 11, further comprising:

a power supply;

a memory configured to communicate with the processor, the memory containing a first parameter set and a second parameter set; and

the processor further configured to receive or produce an estimated remaining lifetime of the power supply, to perform the filtering with the first parameter set if the estimated remaining lifetime is below a first threshold, and to perform the filtierin with the second parameter set if the estimated remaining lifetime is below a second threshold, wherein the first threshold is larger than the second threshold, and wherein the first parameter set results in less attenuation of the particular frequencies than the second parameter set.

20. The apparatus of claim 19, wherein the filtering is done in a transformed domain, and filtering with the second parameter set attenuates lower spatial frequencies in the first dimension than filtering with the first parameter set.

21. The apparatus of claim 19, wherein the filtering is done in a spatial domain, and filtering with the second parameter set combines more spatial coefficients in the first dimension than filtering with the first parameter set.

22. The apparatus of claim 11, wherein the filtering comprises low pass filtering that results in lower spatial frequencies remaining substantially unchanged after filtering.

23. The apparatus of claim 13, wherein the transformed domain is one of a discrete Fourier transformed domain, a discrete cosine transformed domain, a Hadamard transformed domain, a discrete wavelet transformed domain, a discrete sine transformed domain, a Haar transformed domain, a slant transformed domain, a Karhunen-Loeve transformed domain and an H.264 integer transformed domain.

24. The apparatus of claim 11, further comprising:

a memory device in electrical communication with the processor.

25. The apparatus of claim 24, further comprising a controller configured to send at least a portion of the filtered image data to the driver circuit.

26. The apparatus of claim 24, further comprising an image source module configured to send the transformed image data to the processor.

27. The apparatus of claim 26, wherein the image source module comprises at least one of a receiver, transceiver, and transmitter.

28. The apparatus of claim 24, further comprising an input device configured to receive input data and to communicate the input data to the processor.

29. An apparatus for displaying video data, comprising:

at least one driver circuit;

a display device configured to be driven by the driver circuit, the display device requiring more power to be driven to display video data comprising particular spatial frequencies in a first dimension, than to be driven to display video data comprising the particular spatial frequencies in a second dimension;

a processor configured to communicate with the driver circuit, the processor further configured to receive partially decoded video data, wherein the partially decoded video data comprises coefficients in a transformed domain;

the processor further configured to filter the partially decoded video data, wherein the filtering comprises reducing a magnitude of at least one of the transformed domain coefficients containing spatial frequencies within the particular spatial frequencies in the first dimension;

the processor further configured to inverse transform the filtered partially decoded video data, thereby resulting in filtered spatial domain video data;

the processor further configured to finish decoding the filtered spatial domain video data; and

the driver circuit configured to provide the decoded spatial domain video data to the display device.

30. The apparatus of claim 29, wherein the partially decoded video data was encoded with one of an MPEG-2 encoder, an MPEG-4 encoder, and an H.264 encoder.

31. The apparatus of claim 29, wherein the display device comprises an array of interferometric modulators.

32. The apparatus of claim 29, further comprising:

a power supply;

a system controller configured to communicate with the processor, the system controller further configured to receive or produce an estimated remaining lifetime of the power supply; and

wherein the processor is further configured to filter the image data if the estimated remaining lifetime is below a threshold.

33. An apparatus for processing image data, comprising:

means for displaying image data, the displaying means requiring more power to display image data comprising particular spatial frequencies in a first dimension, than to display image data comprising the particular spatial frequencies in a second dimension;

means for receiving image data;

means for filtering the received image data such that the image data at particular spatial frequencies in a first dimension are attenuated more than image data at particular spatial frequencies in a second dimension, so as to reduce power consumed by the displaying means; and

driving means for providing the filtered image data to the displaying means.

34. The apparatus of claim 33, wherein the receiving means comprises a network interface.

35. The apparatus of claim 33, wherein the displaying means comprises an array of interferometric modulators.

36. The apparatus of claim 33, wherein the driver means comprises at least one driver circuit.