Method for recording a color image using dots of colorants of different densities
AssigneeCanon Kabushiki Kaisha
InventorsNobuaki Sakurada, Hideaki Kawamura, Takashi Sasaki
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Abstract
A method for reproducing a halftone color image is disclosed, in which each picture element comprises a plurality of cells and one dot is formed for each cell. At least two colorent densities are used for at least some of the colors. When there is more than one combination of colorants which can represent a given density in a picture element, the combination having the largest number of dots is selected. In a preferred embodiment, more colorants of different densities are used for cyan and magenta then are used for black and yellow.
Claims13
A method for recording a color image by using cyan, magenta and yellow colorants, wherein at least said cyan and magenta colorants each comprise colorants of a number of densities, comprising the steps of:
- forming dots of at least one of the colorants in unit areas of the image;
- and
- controlling the density level of each unit area by selecting the number of dots to be formed in each unit area;
- wherein N.sub.C, N.sub.M and N.sub.Y represent the number of densities of the cyan, magenta, and yellow colorants, respectively, and are selected to satisfy the relation N.sub.M, N.sub.C >N.sub.Y. pg,16
A method for recording a color image by using cyan, magenta and yellow colorants, wherein at least said cyan and magenta colorants each comprise colorants of a number of densities, comprising the steps of:
- recording the image as a plurality of picture elements, wherein each picture element comprises a plurality of cells;
- selecting the numbers N.sub.C, N.sub.M and N.sub.Y of densities of the cyan, magenta and yellow colorants, respectively, to satisfy the relation N.sub.M, N.sub.C >N.sub.Y ;
- forming dots of at least one of the colorants in the cells in accordance with a desired density level for each picture element, wherein dots may be omitted from certain cells to provide the desired density level;
- and
- selecting a combination of the colorants of the numbers of densities for the dots in a given picture element such that when there is more than one combination which will provide about the same density level for said given picture element, the combination which will result in using the largest number of dots in said given picture element is selected.
Dependencies are inferred from the claim text.