Control device capable of generating binary image data expressing suitable gradation levels

摘要

A control device includes a first dither matrix having threshold values assigned to a plurality of cells. The control device converts image data into binary data by using the first dither matrix. The control device converts an input value into ON-pixel or OFF-pixel based on the threshold value. The threshold values in the first dither matrix are arranged such that the ON-pixels grow from a first group of ON-pixels to a second group of ON-pixels as the input value increases. The first group corresponds to cells arranged in M rows and N columns. The second group corresponds to cells arranged in (M+1) rows and (N+1) columns. The second group consists of the first group and a third group corresponding to (M+N+1) number of cells. At least two of the (M+N+1) number of cells are adjacent to each other and have same threshold values.

主权项

1. A control device comprising:
a processor; and a memory that stores computer program that, when executed by the processor, causes the control device to function as:
an image acquiring unit configured to acquire image data having an input value; ana converting unit configured to convert the image data into binary data by using a first dither matrix, the binary data being used in a printing process, the first dither matrix including a plurality of threshold values assigned to a plurality of cells, each of the plurality of cells being assigned respective one of the plurality of threshold values, the converting unit converting the input value into one of ON-pixel and OFF-pixel for each of the plurality of cells by comparing the input value with the respective one of the plurality of threshold values, the ON-pixel being a pixel set to an ON state, the OFF-pixel being a pixel set to an OFF state, wherein the plurality of threshold values in the first dither matrix are arranged such that the ON-pixels grow from a first group of ON-pixels to a second group of ON-pixels as the input value increases, the ON-pixels in the first group corresponding to cells arranged in M rows and N columns, M being a natural number, N being a natural number, the ON-pixels in the second group corresponding to cells arranged in (M+1) rows and (N+1) columns, the second group of the ON-pixels consisting of the first group of ON-pixels and a third group of ON-pixels, the third group of ON-pixels corresponding to (M+N+1) number of cells, at least two of the (M+N+1) number of cells being adjacent to each other and having same threshold values.