Replicating and refreshing graphic images on a remote workstation

• US 5,982,392 A
• Filed: 09/23/1997
• Issued: 11/09/1999
• Est. Priority Date: 09/24/1996
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Perrone, Antonio, Loiodice, Luca, Anfossi, Agostino
• Primary Examiner(s): CHAUHAN, ULKA J
• Application Number:
  US08/932,858
• Time in Patent Office: 777 Days
• Field of Search: 345/329-332, 345/501, 345/502, 345/507, 345/1, 345/2, 345/965, 345/969, 345/971, 395/200.3, 395/200.38-200.41, 395/200.47, 395/200.48, 395/200.6-200.62, 395/200.68, 395/200.72, 395/200.76, 395/726, 709/200, 709/208-211, 709/217-219, 709/230-232, 709/238, 709/246, 709/301
• US Class Current: 345/502
• 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

Abstract

A method and system for remote control of a target computer by a controller computer through a network. The graphic commands issued by the graphic engine of the target computer are "hooked" and translated into a system independent format. The translated commands are then transmitted to the controller computer to be replayed on the display. The independency from the operating system is realized by defining a protocol which is used to translate a subset of the graphic commands in the target computer before the transmission to the controller computer where the commands are re-translated according to the same protocol.

Claims

1. A method for duplicating and refreshing, on at least one destination data processing system a graphic image displayed on a source data processing system, the at least one destination data processing system comprising:

a first display unit for displaying graphic images and

a first display driver for modifying the image on the first display unit;

the source data processing system comprising;

a second display unit for displaying images,

a graphic engine for generating a plurality of graphic commands and

a second display driver for modifying the image on the second display unit according to the graphic commands generated by the graphic engine;

the at least one destination data processing system and the source data processing system being connected through a network, the method comprising the steps of;

intercepting the graphic commands generated by the graphic engine;

passing the graphic command to the second display driver;

translating a subset of the graphic commands into an operating system independent format, according to a predefined protocol;

sending the system independent graphic commands, through the network, to the at least one destination data processing system;

transforming the system independent graphic commands into the at least one destination data processing system format, according to said protocol;

passing the transformed graphic commands to the first display driver;

copying in the storage of the source data processing system a bit-map of the image displayed on the second display unit;

modifying the copied bit-map image according to said subset of graphic commands;

comparing, every predetermined period of time, the copied bit-map image with the image displayed on the second display unit;

if the difference between the copied bit-map image and the image displayed on the second display unit exceeds a predetermined threshold, updating the bit-map image copy and sending, through the network, the bit-map image to the at least one destination data processing system.

2. A system for duplicating and refreshing, on at least one destination data processing system a graphic image displayed on a source data processing system, the at least one destination data processing system comprising:

a first display unit for displaying graphic images and

a first display driver for modifying the image on the first display unit;

the source data processing system comprising;

a second display unit for displaying images,

a graphic engine for generating a plurality of graphic commands and

a second display driver for modifying the image on the second display unit according to the graphic commands generated by the graphic engine;

the at least one destination data processing system and the source data processing system being connected through a network, the system comprising;

means for intercepting the graphic commands generated by the graphic engine;

communication means for passing the graphic command to the second display driver;

means for translating a subset of the graphic commands into an operating system independent format, according to a predefined protocol;

network means for sending the system independent graphic commands to the at least one destination data processing system;

means for transforming the system independent graphic commands into the at least one destination data processing system format, according to said protocol;

communication means for passing the transformed graphic commands to the first display driver;

timer means for counting a predetermined period of time;

means for copying in the storage of the source data processing system a bit-map of the image displayed on the second display unit;

means for modifying the copied bit-map image according to said subset of graphic commands;

means for comparing, every predetermined period of time, the copied bit-map image with the image displayed on the second display unit and for updating the copied bit-map image if the difference exceeds a predetermined threshold;

network means for sending the bit-map image copy to the at least one destination data processing system, if the difference between the bit-map image and the image displayed on the second display unit exceeds a predetermined threshold.

3. A method for duplicating and refreshing, on at least one destination data processing system a graphic image displayed on a source data processing system, the source data processing system comprising:

a first display unit for displaying images,

a graphic engine for generating a plurality of graphic commands and

a first display driver for modifying the image on the first display unit according to the graphic commands generated by the graphic engine;

the at least one destination data processing system comprising;

a second display unit for displaying graphic images and

a second display driver for modifying the image on the second display unit;

the method comprising the steps of;

intercepting the graphic commands generated by the graphic engine;

translating those graphic commands which belong to a predetermined subset into an operating system independent format, according to a predefined protocol;

transmitting the system independent graphic commands to the at least one destination data processing system;

transforming the system independent graphic commands into the at least one destination data processing system format, according to said protocol

creating in the storage of the source data processing system a bit-map copy of the image displayed on the first display unit;

modifying the bit-map copy according to said translated graphic commands;

comparing, every predetermined period of time, the bit-map copy with the image displayed on the first display unit;

if the difference between the bit-map copy and the image displayed on the first display unit exceeds a predetermined threshold, updating the bit-map copy and transmitting the updated bit-map image to the at least one destination data processing system.

4. A system for duplicating and refreshing, on at least one destination data processing system a graphic image displayed on a source data processing system, the source data processing system comprising:

a first display unit for displaying images,

a graphic engine for generating a plurality of graphic commands, and

a first display driver for modifying the image on the first display unit according to the graphic commands generated by the graphic engine;

the at least one destination data processing system comprising;

a second display unit for displaying graphic images, and

a second display driver for modifying the image on the first display unit;

the system comprising;

means for intercepting the graphic commands generated by the graphic engine;

means for translating those graphic commands which belong to a predetermined subset into an operating system independent format, according to a predefined protocol;

means for transmitting the system independent graphic commands to the at least one destination data processing system;

means for transforming the system independent graphic commands into the at least one destination data processing system format, according to said protocol

timer means for counting a predetermined period of time;

means for creating in the storage of the source data processing system a bit-map copy of the image displayed on the first display unit;

means for modifying the bit-map copy according to said translated graphic commands;

means for comparing, every predetermined period of time, the bit-map copy with the image displayed on the first display unit and for updating the bit-map copy if the difference exceeds a predetermined threshold;

means, responsive to said predetermined threshold being exceeded, for transmitting the updated bit-map image to the at least one destination data processing system.