DISPLAYING A SUBSAMPLED VIDEO IMAGE ON A COMPUTER DISPLAY

摘要

Apparatus for displaying a reduced-size image in â window of the display (18) of a host computer (12), the reduced-size image based upon subsampled digital image data. The apparatus includes a host computer (12) and a peripheral controller (10). The peripheral controller (10) includes a subsampler (80) that receives digital source image data and outputs subsampled image data, and window display means (42). The window display means (42) receives a directive from the host computer (12) indicating a window location on the host's display (18), and the subsampled image data. The window display means (42) autonomously (independently of the host CPU (28)) writes the subsampled data through the host's system bus (46) into the display memory (44) at addresses corresponding to the specified window. The apparatus allows video to be displayed on the display screen (18) while avoiding intensive involvement or supervision by the host CPU (28) during display of the video image data.