| 摘要 |
The printing apparatus of the invention provides a black data table, prior to the halftoning process of input image data. The black data table is obtained by converting image data of all black pixels into dot creation data. The printing apparatus performs a specific halftoning process with regard to black/white edges included in an input image with reference to the provided black data table, while keeping the input resolution of the input image data unchanged. The printing apparatus performs a standard halftoning process, on the other hand, with regard to a remaining background image area of the input image, while lowering the input resolution to a reduced resolution. The black/white edges processed by the specific halftoning process are eventually combined with the remaining image parts processed by the standard halftoning process to give a resulting printed image. The halftoning process of the invention is performed at the high resolution with regard to the black/white edges, for example, characters, included in the input image to attain the clear and distinctive printing, while being performed at the reduced resolution with regard to the remaining background image area of the input image to attain the high-speed processing with the reduced data volume. This arrangement desirably enhances the total processing speed of image data including edges, for example, characters.
|
