Image processing apparatus and image processing method

Claim 2

An image processing apparatus for printing an image on a unit area of a printing medium by performing a plurality of relative scans between a printing unit for ejecting inks and the printing medium, said apparatus comprising: a generating unit configured to generate first and second multi-valued data of an image to be printed on the unit area by each of the first and second relative scans of the plurality of relative scans and third multi-valued data of an image to be printed on the unit area by both of the first and second relative scans among the plurality of relative scans, based on the multi-valued image data corresponding to the image to be printed on the unit area, wherein the gradation value of third multi-valued data is determined according to the gradation value of the multi-valued image data; and an obtaining unit configured to obtain a first data used for printing in the first relative scan based on the first multi-valued data and the third multi-valued data and second data used for printing in the second relative scan based on the second multi-valued data and the third multi-valued data.

Claim 3

The image processing apparatus according to claim 1 , wherein said generating unit divides the multi-valued image data according to the division ratios, which make a percentage of a value of the third multi-valued data in the case that the gradation value of the multi-valued image data corresponding to the unit area is smaller than a first threshold value or is greater than a second threshold value that is greater than the first threshold value than that in the case that the gradation value of the multi-valued image data corresponding to the unit area is a value between the first threshold value and the second threshold value.

Claim 4

A non-transitory computer readable medium storing a program that makes the computer function as an image processing apparatus according to claim 1 .

Claim 5

The image processing apparatus according to claim 1 , wherein the first data, second data, and third data are obtained by quantizing the first multi-valued data, the second multi-valued data, and the third multi-valued data respectively by using an error diffusion process.

Claim 6

The image processing apparatus according to claim 4 , further comprising a quantization unit configured to perform quantization processing for each of the first, second and third multi-valued data generated by said generating unit to generate the first, second, and third data, respectively.

Claim 7

An image processing apparatus that, for printing an image on a unit area of a printing medium by performing a plurality of relative scans between a printing unit for ejecting inks of plurality of colors and the printing medium, processes multi-valued image data that corresponds to the image to be printed on the unit area, said apparatus comprising: a selecting unit configured to select a second processing mode in the case that the gradation value of the multi-valued image data is smaller than a first threshold value or is greater than a second threshold value that is greater than the first threshold value, and select a first processing mode in the case that the gradation value of the multi-valued image data is a value between the first threshold value and the second threshold value; and a processing portion configured to perform the processing mode selected by said selecting unit, wherein the first processing mode is a mode that performs an image processing including (A) a first division process for dividing the multi-valued image data into respective multi-valued data that correspond to each of the plurality of relative scans and multi-valued data that corresponds commonly to at least two relative scans among the plurality of relative scans, (B) a first quantization process for quantizing each of the multi-valued data obtained by the first division process to generate respective quantized data that correspond to each of the plurality of relative scans and quantized data that corresponds commonly to the at least two relative scans among the plurality of relative scans, and (C) a combination process for combining the quantized data generated by the first quantization process for each corresponding relative scan to generate combined quantized data that corresponds to each of the plurality of relative scans, and the second processing mode is a mode that performs an image processing including (D) a second quantization process for quantizing the multi-valued data to generate quantized data, and (E) a second division process for dividing the quantized data generated by the second quantization process into respective divided quantized data that correspond to each of the plurality of relative scans.

Claim 8

An image processing apparatus that, for printing an image on a unit area of a printing medium by performing a plurality of relative scans between a printing unit for ejecting inks of plurality of colors and the printing medium, processes multi-valued image data that corresponds to the image to be printed on the unit area, said apparatus comprising: a selecting unit configured to select a second processing mode in the case that the gradation value of the multi-valued image data is smaller than a first threshold value or is greater than a second threshold value that is greater than the first threshold value, and select a first processing mode in the case that the gradation value of the multi-valued image data is a value between the first threshold value and the second threshold value; and a processing portion configured to perform the processing mode selected by said selecting unit, wherein the first processing mode is a mode that performs an image processing including (A) a first division process for dividing the multi-valued image data into respective multi-valued data that correspond to each of the plurality of relative scans and multi-valued data that corresponds commonly to at least two relative scans among the plurality of relative scans, (B) a first quantization process for quantizing each of the multi-valued data obtained by the first division process to generate respective quantized data that correspond to each of the plurality of relative scans and quantized data that corresponds commonly to the at least two relative scans among the plurality of relative scans, and (C) a combination process for combining the quantized data generated by the first quantization process for each corresponding relative scan to generate combined quantized data that corresponds to each of the plurality of relative scans, and the second processing mode is a mode that performs an image processing including (D) a second quantization process for quantizing the multi-valued data to generate quantized data, and (E) a second division process for dividing the quantized data generated by the second quantization process into respective divided quantized data that correspond to each of the plurality of relative scans.

Claim 9

The image processing apparatus according to claim 6 , wherein said selecting unit selects the first processing mode for the multi-valued image data of the unit area that corresponds to a first relative position on the printing medium among relative positions which is changed by the relative scan between the printing unit and the printing medium, and select the second processing mode for the multi-valued image data of the unit area that corresponds to a second relative position on the printing medium, in which a position error of the relative position is smaller than that of the first relative position, among the relative positions, regardless of the gradation value of the multi-valued image data.

Claim 10

An image processing method for printing an image on a unit area of a printing medium by performing a plurality of relative scans between a printing unit for ejecting inks and the printing medium, said method comprising: generating first and second multi-valued data of an image to be printed on the unit area by each of the first and second relative scans of the plurality of relative scans and third multi-valued data of an image to be printed on the unit area by both of the first and second relative scans among the plurality of relative scans, based on multi-valued image data corresponding to the image to be printed on the unit area, wherein the gradation value of third multi-valued data is determined according to the gradation value of the multi-valued image data; and obtaining a first data used for printing in the first relative scan based on the first multi-valued data and the third multi-valued data and second data used for printing in the second relative scan based on the second multi-valued data and the third multi-valued data.

Claim 11

An image processing method for printing an image on a unit area of a printing medium by performing a plurality of relative scans between a printing unit for ejecting inks and the printing medium, said method comprising: generating first and second multi-valued data of an image to be printed on the unit area by each of the first and second relative scans of the plurality of relative scans and third multi-valued data of an image to be printed on the unit area by both of the first and second relative scans among the plurality of relative scans, based on multi-valued image data corresponding to the image to be printed on the unit area, wherein the gradation value of third multi-valued data is determined according to the gradation value of the multi-valued image data; and obtaining a first data used for printing in the first relative scan based on the first multi-valued data and the third multi-valued data and second data used for printing in the second relative scan based on the second multi-valued data and the third multi-valued data.

Claim 12

The image processing method according to claim 8 , wherein said generating step divides the multi-valued image data according to the division ratios, which make a percentage of a value of the third multi-valued data in the case that the gradation value of the multi-valued image data corresponding to the unit area is smaller than a first threshold value or is greater than a second threshold value that is greater than the first threshold value than that in the case that the gradation value of the multi-valued image data corresponding to the unit area is a value between the first threshold value and the second threshold value.

Claim 13

The image processing method according to claim 8 , wherein the first data, second data, and third data are obtained by quantizing the first multi-valued data, the second multi-valued data, and the third multi-valued data respectively by using an error diffusion process.

Claim 14

The image processing method according to claim 10 , further comprising performing quantization processing for each of the first, second and third multi-valued data generated by said generating unit to generate the first, second, and third data, respectively.