| 摘要 |
PURPOSE:To reduce the number of times of coordinate conversions by selecting only necessary picture elements from original bit map data so as not to be overlapped on the converted picture elements, and converting the coordinates. CONSTITUTION:A conversion control parameter computing element 2 is provided, and based on a conversion control parameter 3 obtained from the conversion control parameter computing element 2, the bit map data to be read from an original bit map data storage memory 10 are selected. A coordinate converter 7 applies the coordinate converting formula affine transformation to the original bit map picture element apex coordinates outputted from a coordinate generator 4, and outputs after-conversion picture element apex coordinates 8. A vector raster converter 12 stores bit map data 11 inputted from a bit map data reader 9 on the whole coordinate positions, which have three pairs of after-conversion picture element apex coordinates outputted from the coordinate converter 7 as the four apexes, in a closed area on an after-conversion bit map data storage memory 13. |
