Patent ID: 6356314
Filing Date: 2002-03-12
Classification: G09G,H04N

Abstract:
An image synthesizing device with which a sub-image included in a specific extraction region of an interlaced scan sub-image composed of odd-numbered fields and even-numbered fields is synthesized and displayed within a specific display region of a non-interlaced scan main image displayed on a display, comprising:a first frame memory with which write and read operations can be performed asynchronously and which stores data for odd-numbered fields out of the sub-image in an address region specified by an address signal; a second frame memory with which write and read operations can be performed asynchronously and which stores data for even-numbered fields out of the sub-image in an address region specified by the address signal; write control means for packing and sequentially storing data for odd-numbered fields out of that data within the extraction region to be synthesized out of the sub-image, in a continuous address region of the first frame memory in the order of extraction from the extraction region, and for packing and sequentially storing data for even-numbered fields out of that data within the extraction region to be synthesized out of the sub-image, in a continuous address region of the second frame memory in the order of extraction from the extraction region; read control means for alternately reading the sub-image data stored in the first and second frame memories in the order of the address when the scanning address of the main image data corresponds to being within the display region of the main image; and selection means for selecting the main image data when the scanning address of the main image data is outside the display region of the main image, selecting the sub-image data sequentially read from the first and second frame memories when the scanning address of the main image data is within the display region of the main image, and outputting the selected data to the display.