1. Technical Field
The present invention relates to an image-processing device and a computer program for the image-processing device configured to execute a plurality of types of image processes, whereby the image-processing device receives a specific code for an image process and performs the image process corresponding to the specific code on raster image data to be subjected to image processing.
2. Related Art
One image-processing device known in the art is a data-processing device that operates under WINDOWS (registered trademark) or another operating system. This type of data-processing device performs raster operation (ROP) processes in order to draw two or more raster images superimposed over each other. Specifically, the data-processing device performs ROP processes to perform logic operations corresponding to a ROP code using the source data and the destination raster image data, thereby executing image processes on destination raster image data based on source data. Here, source data is raster image data provided for the image process (ROP process). More specifically, the source data denotes data submitted into operands used for operational expressions (logic operations).
The ROP code is an integer specifying an image process. The data-processing device implements a plurality of types of image processes corresponding to the number of ROP codes. Hence, upon receiving a ROP code, this type of data-processing device executes an image process corresponding to the ROP code by performing logic operations corresponding to the ROP code, using the destination raster image data and source data.
A plurality of standards exists for ROP processes, including ROP2, ROP3, and ROP4. In a ROP process according to the ROP3 standard, for example, an image process corresponding to the ROP code is implemented by performing logic operations using two types of source data and the destination raster image data.
More specifically, in a ROP process according to the ROP3 standard, an image process is executed on the raster image data targeted for processing (destination bitmap) using brush data configured of raster image data of a standard size and a source bitmap configured of raster image data of an arbitrary size as the source data.
In a ROP process using the source bitmap, an image process corresponding to the ROP code is performed on a region of the destination bitmap having the same size as the source bitmap by performing logic operations on the region using the source bitmap.
In a ROP process using brush data, on the other hand, the image process corresponding to the ROP code is executed on a region of the destination bitmap targeted for image processing by performing logic operations using brush data on sections of the target region having a standard size, thereby forming a pattern in the destination bitmap. ROP process using brush data are used for achieving a brush effect (a filled-in effect).
Data that has undergone such a ROP process is inputted into an image-forming device, such as a printing device, for image formation (printing). If the data inputted into the image-forming device underwent a ROP process using brush data, in some cases the resolution of the resulting image is too high or the pattern generated by the brush data is rendered very small, depending on the type of image-forming device. As shown in FIG. 18, a brush drawing results from drawing an image based on raster image data that has undergone a ROP process using the same brush data when using an image-forming device having a low drawing capacity (a low printing resolution) and an image-forming device having a high drawing capacity (a high printing resolution).
This phenomenon occurs because the drawing capacity (printing resolution) of the image-forming device differs according to the device, even though the brush data has been standardized at a fixed size. When the image-forming device has a high drawing capacity, the dot density of the image formed on the image-forming member is high. Hence, when patterns are formed in sections of a standard size (standard number of dots), the patterns are rendered in miniature on the image-forming member.
In order to overcome this problem, Japanese patent application publication No. 2003-331297 discloses a method of enlarging the pattern virtually by modifying the dot pattern according to the printing resolution while maintaining the dot pattern of the brush data at the same size (standard size).
However, in some cases it is difficult to enlarge the pattern with the conventional method described above, depending on the type of pattern, such as complex dot patterns. Further, with image-forming devices having a high resolution, it has been difficult to take sufficient measures to avoid the phenomenon of the pattern being rendered too small. Further, since ROP processes are not considered in this conventional method, it may be difficult to adequately enlarge and render patterns using the technique described above, depending on the content of the ROP process.