Scanning display driver
First Claim
1. A computer implemented method for generating on a display of a remote computer a video image produced on a display of a host computer, the host computer being accessed by the remote computer through a remote control program, the host computer including a graphics driver interface (GDI) for converting device-independent function calls into device-dependent function calls suitable for the display hardware of the host computer the method comprising the steps of:
- retrieving a device-independent bit map segment from the GDI of the host computer responsive to a device-independent function call;
calculating a current status characteristic of the retrieved bit map segment;
comparing the current status characteristic with a stored status characteristic of the retrieved bit map segment; and
transferring the retrieved bit map segment to the remote computer when the current status characteristic and the stored status characteristic of the bit map segment are unequal.
2 Assignments
0 Petitions
Accused Products
Abstract
A remote control program (230) includes a scanning display driver (232) that interacts with the graphics display driver (112) of a host computer (110) to provide to the display (122) of the remote computer (120) an image (117) generated on the display (116) of the host computer (110). The scanning display driver (232) employs device independent function calls to the GDI (112) of the host computer (110) to eliminate any hardware dependent artifacts from the remote computer display (122). A scanning module (234) in the scanning display driver (112) retrieves bit map segments (119) of the image (117) on the host display (116), calculates a checksum value for comparison with a stored checksum value (542), updates the stored value (542) when the bit map segment (119) has been changed, and sets a flag (544) to indicate a new checksum value has been stored. An update module (236) scans the flags (544) and operates in conjunction with a communication module (240) to transfer changed bit map segments (119) to the remote computer (120). Transferred bit map segments (129) are stored in the remote computer (120) and used to refresh the image (127) on the remote display (122) until a new checksum value indicates that the bit map segment (119) on the host display (116) has been changed.
19 Citations
12 Claims
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1. A computer implemented method for generating on a display of a remote computer a video image produced on a display of a host computer, the host computer being accessed by the remote computer through a remote control program, the host computer including a graphics driver interface (GDI) for converting device-independent function calls into device-dependent function calls suitable for the display hardware of the host computer the method comprising the steps of:
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retrieving a device-independent bit map segment from the GDI of the host computer responsive to a device-independent function call; calculating a current status characteristic of the retrieved bit map segment; comparing the current status characteristic with a stored status characteristic of the retrieved bit map segment; and transferring the retrieved bit map segment to the remote computer when the current status characteristic and the stored status characteristic of the bit map segment are unequal. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A system for generating on a display of a remote computer a video image produced on a display of a host computer, the host computer being accessed by the remote computer through a remote control program the host computer including a graphics driver interface (GDI) for converting device-independent function calls into device-dependent function calls suitable for the display hardware of the host computer, the system comprising:
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a scanning display driver coupled to the GDI for accessing through device-independent function calls a plurality of device-independent bit map segments generated by the host computer, for scanning the device-independent bit map segments in order to determine which segments have been changed by the host computer, and for generating a status characteristic for the device-independent bit map segments; a memory location coupled to the scanning display driver for storing the status characteristics of the device-independent bit map segments; a communication module coupled to the scanning display driver for transferring device-independent bit map segments to the remote computer and for receiving commands from the remote computer; and an update module coupled to the memory location and the communication module for scanning the status characteristics of the device-independent bit map segments and identifying selected bit map segments to the communication module for transferring to the remote computer. - View Dependent Claims (9, 10, 11, 12)
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Specification