| 摘要 |
PURPOSE:To easily synthesize a picture and to synthesize a picture larger than a display screen with the entirely displayed by selecting either one brightness information of the first and the second picture information according to mask control information and displaying on the display screen based on the brightness information. CONSTITUTION:The compressed ground picture of a memory unit 5, the compressed and synthesized picture of a memory unit 6 and the compressed mask picture of a mask memory unit 7 are inputted to a synthesizer 8. The brightness information of the compressed picture data is only latched to latch circuits 31, 30. A latch circuit 29 latches the bit of a CRT mask flag in the compressed mask data. In a switching circuit 28, the output of the latch circuit 30 is selected when the output of the latch circuit 29 is '1' and the output of the latch circuit 31 is selected when it is '0'. A lock up table 27 converts the output into a signal fed to a display device 9 according to the brightness information outputted from the switching circuit 28. The picture data is constituted of the bit indicating the brightness information and a bit indicating form information indicating a form. The mark data is constituted of mask form information of 4X4 and the CRT mask flag of one bit. |
