System for determining more accurate translation between first and second translator, and providing translated data to second computer if first translator is more accurate

• US 5,864,711 A
• Filed: 07/05/1995
• Issued: 01/26/1999
• Est. Priority Date: 07/05/1995
• Status: Expired due to Term

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation), Picturetel Corporation (Plantronics, Inc.)
• Original Assignee: Microsoft Corporation
• Inventors: MacFarquhar, Roderick F., Pollitt, Alex J., Batty, John P., Downes, Anthony M., Hughes, Kenneth P., Mairs, Christopher J., Berry, Mark E.
• Primary Examiner(s): Lee, Thomas C.
• Assistant Examiner(s): Chen, Anderson I.
• Application Number:
  US08/498,329
• Time in Patent Office: 1,301 Days
• Field of Search: 345/116, 345/136, 345/332, 345/433, 395/135, 395/200.04, 395/329, 395/522, 395/502, 395/110, 395/856, 395/888, 358/452, 704/3
• US Class Current: 710/6
• CPC Class Codes: G06F 3/1462 with means for detecting differences between the image stored in the host and the images displayed on the remote displays
• CPC Class Codes: G06T 9/005 Statistical coding, e.g. Huffman, run length coding

Abstract

A method and system sharing an application running on a host computer with a remote computer by simultaneously displaying the application'"'"'s screen output on both computers. Simultaneous display of screen output is achieved by efficiently transmitting display data from the host computer to the remote computer. Data that will not result in a visible display on the remote computer is detected by the host computer and not transmitted, eliminating unnecessary transmission and processing of data by the remote computer. Pixel depth translation is done on the computer system capable of most accurately translating pixel depth. When the font used by the host computer for displaying text is not available on the remote computer, the host computer sends a bitmap representation of the text for display, rather than the text itself Bitmap representations are cached by the remote computer, so that the same bitmap representation need not be repeatedly transmitted from the host computer to the remote computer. Bitmap representations are compressed by the host computer prior to transmission.

Claims

1. A method for transmitting pixel data from a first computer system to a second computer system, the pixel data having a high pixel depth, the first computer system having a first translator for translating pixel data from the high pixel depth to a low pixel depth, the second computer system having a second translator for translating from the higher pixel depth to a low pixel depth, the second computer system having a display device for displaying pixel data in the low pixel depth, the method comprising the steps of:

determining whether the first translator or the second translator performs a more accurate translation of the higher pixel depth to the lower pixel depth; and

when it is determined that the first translator performs a more accurate translation,

translating the pixel data using the first translator from the high pixel depth to the low pixel depth; and

sending the pixel data in the low pixel depth from the first computer system to the second computer system; and

upon receiving the sent pixel data in the low pixel depth at the second computer system, displaying the pixel data in the low pixel depth; and

when it is determined that the second translator performs a more accurate translation,

sending the pixel data in the high pixel depth from the first computer system to the second computer system; and

upon receiving the sent pixel data in the high pixel depth at the second computer,

translating the pixel data using the second translator from the high pixel depth to the low pixel depth; and

displaying the pixel data in the low pixel depth.

2. A method for transmitting data from a first computer system to a second computer system, the data for displaying on a display of the second computer system, the method comprising the steps of:

under control of the second computer system, without solicitation from the first computer sending to the first computer system an identification of each font supported by the second computer system;

under control of the first computer system,

receiving the sent identifications of each font supported by the second computer system;

receiving a request to display text data in a specified font on the second computer system;

checking the received identifications to determine whether the second computer program supports the specified font;

when it is determined that the second computer program supports the specified font, sending the text data along with an identification of the specified font to the second computer program; and

when it is determined that the second computer program does not support the specified font,

generating a bitmap representation of the text data in the specified font; and

sending the generated bitmap representation of the text data to the second computer program; and

under control of the second computer program,

upon receiving the sent text data and the identification of the specified font, displaying the text data in the specified font; and

upon receiving the sent bitmap representation of the text data, displaying the bitmap representation.

3. A computer-readable storage device containing instructions for controlling a computer system to transmit pixel data from a first computer system to a second computer system, the pixel data having a high pixel depth, the first computer system having a first translator for translating pixel data from the high pixel depth to a low pixel depth, the second computer system having a second translator for translating from the higher pixel depth to a low pixel depth, by:

determining whether the first translator or the second translator performs a more accurate translation of the higher pixel depth to the lower pixel depth;

when it is determined that the first translator performs a more accurate translation,

translating the pixel data using the first translator from the high pixel depth to the low pixel depth; and

sending the pixel data in the low pixel depth from the first computer system to the second computer system; and

when it is determined that the second translator performs a more accurate translation,

sending the pixel data in the high pixel depth from the first computer system to the second computer system; and

upon receiving the sent pixel data in the high pixel depth at the second computer, translating the pixel data using the second translator from the high pixel depth to the low pixel depth.

4. A computer-readable storage device containing instructions for controlling a computer system to transmit graphics display data from a first computer system to a second computer system by:

under control of the second computer system, without solicitation from the first computer, sending to the first computer system an identification of each font supported by the second computer system;

under control of the first computer system,

receiving the sent identifications of each font supported by the second computer system;

receiving a request to display text data in a specified font on the second computer system;

checking the received identifications to determine whether the second computer program supports the specified font;

when it is determined that the second computer program supports the specified font, sending the text data along with an identification of the specified font to the second computer program; and

when it is determined that the second computer program does not support the specified font,

generating a bitmap representation of the text data in the specified font; and

sending the generated bitmap representation of the text data to the second computer program; and

under control of the second computer program,

upon receiving the sent text data and the identification of the specified font, displaying the text data in the specified font; and

upon receiving the sent bitmap representation of the text data, displaying the bitmap representation.

5. A method for providing data from a first computer to second computer, the data being representable in a high resolution and a low resolution, the first computer having a first translator for translating the data from the high resolution to the low resolution, the second computer having a second translator for translating the data from the high resolution to the low resolution, the second computer capable of processing data in the low resolution, the method comprising:

determining whether the first translator or the second translator performs a more accurate translation of data from high resolution to low resolution;

when it is determined that the first translator performs a more accurate translation,

translating the data using the first translator from the high resolution to the low resolution; and

providing the data translated to the low resolution to the second computer so that the second computer can process the data without translating; and

when it is determined that the second translator performs a more accurate translation,

providing the data in the high resolution to the second computer so that the second computer can use the second translator to translate the provided data in the high resolution to the low resolution before processing the data

whereby the second computer processes the data that has been translated to the low resolution using the more accurate translator.

6. The method of claim 5 wherein the data is pixel data and the resolution is represented by pixel depth.

7. The method of claim 5 wherein the processing of the data in the low resolution includes displaying the data on an output device.

8. A computer-readable medium containing instructions for causing a computer system to provide data from a first computer to a second computer, the data being representable in first form and a second form, the first computer having a first translator for translating the data from the first form to the second form, the second computer having a second translator for translating the data from the first form to the second form, the second computer capable of processing data in the second form, the method comprising:

determining whether the first translator or the second translator performs a more accurate translation of data from the first form to the second form;

when it is determined that the first translator performs a more accurate translation,

translating the data using the first translator from the first form to the second form; and

providing the data translated to the second form to the second computer so that the second computer can process the data without translating; and

when it is determined that the second translator performs a more accurate translation,

providing the data in the first form to the second computer so that the second computer can use the second translator to translate the provided data in the first form to the second form before processing the data.

9. The computer-readable medium of claim 8 wherein the data is pixel data and the form is represented by pixel depth.

10. The computer readable method of claim 8 wherein the processing of the data in the second form includes displaying the data on an output device.