WINDOW-MANAGED IMAGE BLENDING CIRCUIT AND WEIGHTED MEAN CIRCUIT USED FOR THE SAME

摘要

PURPOSE:To provide a superior window-managed image blending circuit which can set the blending rate with a small write information amount by blending superposed images into a translucent image in an area where windows overlap with each other when an information processor displays plural windows. CONSTITUTION:By pixel position information including the pixel clock of a pixel position information supply device 101, 1st and 2nd image memories 102 and 103 output respective pixels and a counter 105 is placed in counting operation, and, respective blending rates are read out of the counter 105 and a blending rate buffer 106, and those blending rates are selected by a data selector 107 with the control signal read out of an attribute buffer 108 and inputted to a pixel blending device 104, which puts pixels from the 1st and 2nd image memories 102 and 103 together into the translucent image at the blending rates or selects them.