Technique for Image Data Recording

Abstract

In an image output control system, an image processing device processes image data in accordance with a preset series of image processing and supplies processed image data to an image output device, which outputs the processed image. The image processing device determines the number of dots to be created in each pixel group, which has a preset number of multiple pixels included in an image, and outputs the number of dots as dot number data to the output device. In response to the dot number data, the output device selects one among multiple options for a priority order of individual pixels included in each pixel group, determines the positions of dot-on pixels in the pixel group, and creates dots at the determined positions of the dot-on pixels to output an image. In the image output control system, the image processing device supplies the dot number data to the output device.

1 . An image output control system comprising an image processing device that makes image data subjected to a preset series of image processing, and an image output device that creates multiple different types of dots having different densities per unit area according to a result of the preset series of image processing, so as to output an image,
 said image processing device comprising:   a dot number determination module that determines a number of dots to be created in each pixel group, which is set to have a predetermined number of multiple pixels having a two-dimensional size comprising multiple pixels arranged in primary and secondary scan directions included in the image, with respect to each of the multiple different types of dots according to the image data; and   a number data output module that outputs the determined number of dots to be created in the pixel group with respect to each type of dot, as dot number data of the pixel group, to said image output device,   said image output device comprising:   a number data receiving module that receives the dot number data of the pixel group with respect to each type of dot;   a priority order specification module that specifies a priority order of individual pixels in the pixel group for dot creation;   a pixel position determination module that determines positions of dot-on pixels in the pixel group with respect to each type of dot, based on the dot number data of the pixel group with respect to each type of dot and the specified priority order; and   a dot formation module that creates the multiple different types of dots at the determined positions of the dot-on pixels.   
     
     
         2 . An image output control system in accordance with  claim 1 , wherein said priority order specification module selects one out of multiple options for the priority order, which are provided in advance, with respect to the pixel group. 
     
     
         3 . An image output control system in accordance with  claim 1 , wherein said number data output module has a dot number combination mapping table that maps each combination of numbers of the multiple different types of dots to a preset code,
 said number data output module refers to the dot number combination mapping table to convert a combination of the numbers of the respective types of dots determined with respect to the pixel group to a corresponding preset code and outputs the preset code, in place of the dot number data of the pixel group, to said image output device, and   said number data receiving module comprises:   a code mapping table that maps each preset code to a combination of the numbers of the multiple different types of dots; and   a number data conversion module that receives the output preset code of the pixel group, and refers to the code mapping table to reconvert the received preset code to dot number data of the pixel group with respect to each type of dot.   
     
     
         4 . An image output control system in accordance with  claim 1 , wherein said pixel position determination module sequentially determines the positions of the dot-on pixels with respect to each type of dot in a descending order of the density per unit area of the multiple different types of dots. 
     
     
         5 . An image output control method that makes image data subjected to a preset series of image processing and creates multiple different types of dots having different densities per unit area according to a result of the preset series of image processing, so as to output an image,
 said image output control method comprising:   determining a number of dots to be created in each pixel group, which is set to have a predetermined number of multiple pixels having a two-dimensional size comprising multiple pixels arranged in primary and secondary scan directions included in the image, with respect to each of the multiple different types of dots according to the image data;   specifying a priority order of individual pixels in the pixel group for dot creation;   determining positions of dot-on pixels in the pixel group with respect to each type of dot, based on the determined number of dots to be created in the pixel group with respect to the type of dot and the specified priority order; and   creating the multiple different types of dots at the determined positions of the dot-on pixels on an output medium.   
     
     
         6 . A computer program product comprising a computer-readable storage medium having an image output control program stored thereon, the image output control program being executed by a computer to make image data subjected to a preset series of image processing and create multiple different types of dots having different densities per unit area according to a result of the preset series of image processing, thus outputting an image, the image output control program comprising:
 a first program code for determining a number of dots to be created in each pixel group, which is set to have a predetermined number of multiple pixels having a two-dimensional size comprising multiple pixels arranged in primary and secondary scan directions included in the image, with respect to each of the multiple different types of dots according to the image data;   a second program code for specifying a priority order of individual pixels in the pixel group for dot creation;   a third program code for determining positions of dot-on pixels in the pixel group with respect to each type of dot, based on the determined number of dots to be created in the pixel group with respect to the type of dot and the specified priority order; and   a fourth program code for creating the multiple different types of dots at the determined positions of the dot-on pixels on an output medium.   
     
     
         7 . An image output control system comprising an image processing device that makes image data subjected to a preset series of image processing, and an image output device that creates multiple different types of dots having different densities per unit area according to a result of the preset series of image processing, so as to output an image,
 said image processing device comprising:   a number calculator that calculates a number of dots to be created in each pixel group, which is set to have a predetermined number of multiple pixels having a two-dimensional size comprising multiple pixels arranged in primary and secondary scan directions included in the image, with respect to each of the multiple different types of dots according to the image data; and   a data transmitter that outputs the calculated number of dots to be created in the pixel group with respect to each type of dot, as dot number data of the pixel group, to said image output device,   said image output device comprising:   a data receiver that receives the dot number data of the pixel group with respect to each type of dot;   a priority order operator that specifies a priority order of individual pixels in the pixel group for dot creation;   a position setter that sets positions of dot-on pixels in the pixel group with respect to each type of dot, based on the dot number data of the pixel group with respect to each type of dot and the specified priority order; and   a dot creator that creates the multiple different types of dots at the set positions of the dot-on pixels.   
     
     
         8 . An image output control system in accordance with  claim 1 , wherein said dot number determination module uses one correspondence relation defined for each pixel group among previously prepared multiple correspondence relations to determine the number of dots, and
 said correspondence relation is obtained from the arrangement of multiple threshold values, which corresponds to the number of pixels included in the pixel group and is taken out from a global dither matrix.   
     
     
         9 . The image output control system in accordance with  claim 1 , wherein the pixel group has M×N pixels, with M and N being integers greater than one. 
     
     
         10 . The image output control system in accordance with  claim 9 , wherein the pixel group includes 4×2 pixels.