Verfahren und Vorrichtung zum Codieren und Anzeigen von überlappenden Fenstern mit Transparenz

摘要

A method and apparatus for the coding and efficient display of overlapping windows with transparency is disclosed. Each pixel within a window which is not to be displayed may be coded as a "transparent" pixel. The disclosed method identifies those pixels which have been coded as transparent and displays non-transparent pixels contained in windows of lower display priority in place of the transparent pixels contained in windows of higher display priority. A pixel coded as transparent may have associated with it an integer representative of the number of successive pixels in the window which are also transparent. A pixel may be coded as transparent by assigning to it a preselected data value which is distinct from values otherwise used to indicate, e.g., the color and/or intensity for each displayed pixel. The disclosed method and apparatus may include one or more windows which contain full motion video (i.e., television) images, each of which may also contain transparent pixels. A pixel also may be coded as a "translucent" pixel, whereby a combination of the translucent pixel and a non-translucent pixel contained in a window of lower display priority is displayed. The disclosed method may be used to efficiently recognize various conditions in the displayed image, including the collision of objects and the pointing of a displayed cursor to identified "hot spots."