| 摘要 |
PURPOSE:To display only necessary display items as an image by composing and displaying the image of map data on the necessary display items among map image data which are different by display items by a control means. CONSTITUTION:When an area name is inputted on a keyboard 24, map image data on the area is read out of a map image file 1 and written as individual virtual image planes A1 - A9 in nine areas set in a RAM 22 corresponding to the respective display items. When display items required to display a map are specified with the numbers A1 - A9 of the individual virtual image planes, only specified image planes are read out, and composed for each layer, and the composite data is written in the RAM 22. A virtual image plane B for composition is reduced and transferred to four layers of the video RAM in a control part 26, and the composite image of the four layers is displayed on a display 3. When width and height which are necessary for display operation are specified on the picture by using a mouse 25, only the part in the virtual image plane B for display is enlarged or reduced and displayed on the display 3 through an area D. |
