Image Generation

• US 20140267321A1
• Filed: 03/13/2013
• Published: 09/18/2014
• Est. Priority Date: 03/13/2013
• Status: Active Grant

• Current Assignee: DisplayLink Corporation (Synaptics Incorporated)
• Original Assignee: DisplayLink Corporation (Synaptics Incorporated)
• Inventors: Stoye, William
• Granted Patent: US 9,165,538 B2
• Time in Patent Office: Days
• US Class Current: 345/520
• CPC Class Codes: G06F 3/1415 with means for detecting differences between the image stored in the host and the images displayed on the displays
• CPC Class Codes: G06F 3/1423 controlling a plurality of local displays, e.g. CRT and flat panel display
• CPC Class Codes: G06T 1/60 Memory management
• CPC Class Codes: G09G 2340/02 Handling of images in compressed format, e.g. JPEG, MPEG
• CPC Class Codes: G09G 2370/12 Use of DVI or HDMI protocol in interfaces along the display data pipeline
• CPC Class Codes: G09G 5/006 Details of the interface to the display terminal specific for a display terminal using a CRT G09G1/167; using a flat panel G09G3/2096; circuits for interfacing with colour displays G09G5/04
• CPC Class Codes: G09G 5/395 Arrangements specially adapted for transferring the contents of the bit-mapped memory to the screen G09G5/399 takes precedence
• CPC Class Codes: H04N 21/4122 additional display device, e.g. video projector digital output for controlling a plurality of local displays G06F3/1423
• CPC Class Codes: H04N 21/43632 involving a wired protocol, e.g. IEEE 1394 high-speed IEEE 1394 serial bus H04L12/40052

Abstract

A method of generating an image comprises receiving a signal over a USB interface comprising encoded display data for one or more rectangular group of pixel tiles within an image and position data for the or each group of pixel tiles. The coefficients are obtained from the encoded display data, maybe by converting variable bit length fields into AC coefficients and an inverse Haar transform performed on them to generate pixel data for each rectangular group of pixel tiles. A frame buffer, which may be part of the display, is then updated with the generated pixel data ready for output to the display device. Copy protection may also be incorporated using AES negotiated over HDPC.

Claims

1. A method of generating an image comprising:

receiving a signal comprising encoded display data for one or more rectangular groups of pixel tiles within an image and position data for each group of pixel tiles,

obtaining coefficients from the encoded display data,

performing an inverse Haar transform on the obtained coefficients to generate pixel data for each rectangular group of pixel tiles,

updating a frame buffer with the generated pixel data, and

outputting at least a portion of the frame buffer.

2. A method according to claim 1, wherein a pixel tile comprises an 8×

8 array of pixels.

3. A method according to claim 1, wherein a rectangular group of pixel tiles comprises fewer than twenty pixel tiles.

4. A method according to claim 1, wherein obtaining coefficients from the encoded display data comprises converting variable length bit fields into AC coefficients.

5. A method according to claim 1, wherein the received signal is received over a USB connection.

6. A method according to claim 1, further comprising, prior to receiving the signal:

encoding display data for one or more rectangular groups of pixel tiles within an image and position data for each of the rectangular groups of pixel tiles, the display data being less than the display data for an entire image, the encoding using a Haar transform for each pixel tile, and

transmitting an encoded signal of the encoded display data to a display control device.

7. A device for generating an image comprising:

a receiver arranged to receive a signal comprising encoded display data for one or more rectangular groups of pixel tiles within an image and position data for the or each group of pixel tiles,

a processor arranged to obtain coefficients from the encoded display data, to perform an inverse Haar transform on the obtained coefficients to generate pixel data for the or each rectangular group of pixel tiles and to update a frame buffer with the generated pixel data, and

an output device arranged to output at least a portion of the frame buffer.

8. A device according to claim 7, wherein a pixel tile comprises an 8×

8 array of pixels.

9. A device according to claim 7, wherein a rectangular group of pixel tiles comprises fewer than twenty pixel tiles.

10. A device according to claim 7, wherein the processor is arranged, when obtaining coefficients from the encoded display data, to convert variable length bit fields into AC coefficients.

11. A device according to claim 7, wherein the receiver comprises a USB port.

12. A system for generating an image comprising:

a computer arranged to encode display data for one or more rectangular groups of pixel tiles within an image and position data for each of the rectangular groups of pixel tiles, the display data being less than the display data for an entire image, the encoding using a Haar transform for each pixel tile and transmit an encoded signal of the encoded display data to a display control device,

a display control device comprising;

a receiver arranged to receive the signal comprising encoded display data for one or more rectangular groups of pixel tiles within an image and position data for the or each group of pixel tiles,

a processor arranged to obtain coefficients from the encoded display data, to perform an inverse Haar transform on the obtained coefficients to generate pixel data for each rectangular group of pixel tiles and to update a frame buffer with the generated pixel data, and

an output device arranged to output at least a portion of the frame buffer.

13. A system according to claim 12, wherein a pixel tile comprises an 8×

8 array of pixels.

14. A system according to claim 12, wherein a rectangular group of pixel tiles comprises fewer than twenty pixel tiles.

15. A system according to claim 12, wherein the processor is arranged, when obtaining coefficients from the encoded display data, to convert variable length bit fields into AC coefficients.

16. A system according to claim 12, wherein the receiver comprises a USB port.

17. A tangible computer readable medium including executable instructions which, when executed in a processing system, cause the processing system to:

receive a signal comprising encoded display data for one or more rectangular groups of pixel tiles within an image and position data for each group of pixel tiles,

obtain coefficients from the encoded display data,

perform an inverse Haar transform on the obtained coefficients to generate pixel data for each rectangular group of pixel tiles,

update a frame buffer with the generated pixel data, and

output at least a portion of the frame buffer.

18. A tangible computer readable medium according to claim 17, wherein a pixel tile comprises an 8×

8 array of pixels.

19. A tangible computer readable medium according to claim 17, wherein a rectangular group of pixel tiles comprises fewer than twenty pixel tiles.

20. A tangible computer readable medium according to claim 17, wherein causing the processing system to obtain coefficients from the encoded display data comprises causing the processing system to convert variable length bit fields into AC coefficients.

21. A tangible computer readable medium according to claim 17, wherein the received signal is received over a USB connection.

22. A tangible computer readable medium according to claim 17, wherein the executable instructions further cause the processing system, prior to receiving the signal, to:

encode display data for one or more rectangular groups of pixel tiles within an image and position data for each of the rectangular groups of pixel tiles, the display data being less than the display data for an entire image, the encoding using a Haar transform for each pixel tile, and

transmit an encoded signal of the encoded display data to a display control device.