Image Generation

Abstract

A method of generating an image comprises receiving a signal over a USB interface comprising encoded display data for one or more groups of pixels within an image, the encoded display data comprising display data for less than the whole of the image, and position data for the or each group of pixels. The encoded display data is decoded to generate pixel data for each group of pixels. A frame buffer, which may be part of the display, is then updated with the generated pixel data according to the position data ready for output to the display device.

1 . A method of generating an image comprising:
 maintaining, at a display control device, a frame buffer having display data for an entire image, the display data comprising pixel data for each pixel of the image;   receiving a signal over a general purpose data connection at the display control device, the signal comprising encoded display data for one or more groups of pixels within the image, the encoded display data comprising display data for less than the whole of the image, and position data indicating a position of the one or more groups of pixels within the image,   decoding the encoded display data to generate pixel data for the one or more groups of pixels,   updating the frame buffer with the generated pixel data for the one or more groups of pixels according to the position data for the one or more groups of pixels, whereby the pixel data for the one or more groups of pixels provide a partial update of the image, and   outputting at least a portion of the display data stored in the frame buffer to a display over a display-specific data standard connection.   
     
     
         2 . A method according to  claim 1 , wherein a group of pixels comprises a group of pixel tiles, wherein a pixel tile comprises an 8×8 array of pixels. 
     
     
         3 . A method according to  claim 2 , wherein a group of pixel tiles comprises fewer than twenty pixel tiles. 
     
     
         4 . A method according to  claim 1 , wherein decoding the encoded display data comprises obtaining a coefficient for the one or more groups of pixels from the encoded display data by converting variable length bit fields in the encoded display data into AC coefficients. 
     
     
         5 . A method according to  claim 1 , wherein the general purpose data connection comprises a USB connection or an Ethernet connection. 
     
     
         6 . A method according to  claim 1 , wherein the display-specific data standard connection comprises a VGA, HDMI, DVI or DisplayPort connection. 
     
     
         7 . A method according to  claim 1 , wherein the one or more groups of pixels are located anywhere within the image. 
     
     
         8 . A method according to  claim 1 , wherein the position data separately identifies the intended location of the one or more groups of pixels in the frame buffer. 
     
     
         9 . A device for generating an image comprising:
 a frame buffer configured to store display data for an entire image, the display data comprising pixel data for each pixel of the image;   a receiver arranged to receive a signal over a general purpose data connection, the signal comprising display data for one or more groups of pixels within the image, the encoded display data comprising display data for less than the whole of the image, and position data indicating a position of the one or more groups of pixels within the image,   a processor arranged to decode the encoded display data to generate pixel data for the one or more groups of pixels and to update the frame buffer with the generated pixel data for the one or more groups of pixels according to the position data for the one or more groups of pixels, whereby pixel data for the one or more groups of pixels provide a partial update of the image, and   an output device arranged to output at least a portion of the display data stored in the frame buffer to a display over a display-specific data standard connection.   
     
     
         10 . A device according to  claim 9 , wherein a group of pixels comprises a group of pixel tiles, wherein a pixel tile comprises an 8×8 array of pixels. 
     
     
         11 . A device according to  claim 10 , wherein a group of pixel tiles comprises fewer than twenty pixel tiles. 
     
     
         12 . A device according to  claim 9 , wherein the processor is configured, when decoding the encoded display data, to obtain a coefficient for the one or more groups of pixels from the encoded display data by converting variable length bit fields in the encoded display data into AC coefficients. 
     
     
         13 . A device according to  claim 9 , wherein the receiver comprises a USB port or an Ethernet port. 
     
     
         14 . A device according to  claim 9 , wherein the display-specific data standard connection comprises a VGA, HDMI, DVI or DisplayPort connection. 
     
     
         15 . A device according to  claim 9 , wherein the one or more groups of pixels are located anywhere within the image. 
     
     
         16 . A device according to  claim 9 , wherein the position data separately identifies the intended location of the one or more groups of pixels in the frame buffer. 
     
     
         17 . A system comprising the device of  claim 9 , and further including:
 a computer arranged to encode the display data for the one or more groups of pixels within the image and the position data indicating the position of each of the groups of pixels within the image, the display data being less than the display data for an entire image, and to transmit an encoded signal of encoded display data to the device over the general purpose data connection.   
     
     
         18 . A tangible non-transitory computer readable medium including executable instructions which, when executed in a processing system, cause the processing system to:
 maintain, at a display control device, a frame buffer having display data for an entire image, the display data comprising pixel data for each pixel of the image;   receive a signal over a general purpose data connection at the display control device, the signal comprising display data for one or more groups of pixels within the image, the encoded display data comprising display data for less than the whole of the image, and position data indicating a position of the or one or more groups of pixels within the image,   decode the encoded display data to generate pixel data for the one or more groups of pixels,   update the frame buffer with the generated pixel data for the one or more groups of pixels according to the position data for the one or more groups of pixels, whereby the one or more groups of pixels provide a partial update of the image, and   output at least a portion of the display data stored in the frame buffer to a display over a display-specific data standard connection.   
     
     
         19 . A tangible computer readable medium according to  claim 18 , wherein a group of pixels comprises a group of pixel tiles, wherein a pixel tile comprises an 8×8 array of pixels. 
     
     
         20 . A tangible computer readable medium according to  claim 18 , wherein the executable instructions that cause the processing system to decode the encoded display data comprises instructions that cause the processing system to obtain a coefficient for the one or more groups of pixels from the encoded display data by converting variable length bit fields in the encoded display data into AC coefficients.