Image processing apparatus and method, and printing method and apparatus

Claim 2

An image processing apparatus for processing multilevel image data, comprising: dividing means for dividing the multilevel image data into pixel blocks each comprising a plurality of pixels; conversion tables each containing a plurality of items of conversion data, each item corresponding to a pixel position in each pixel block obtained by division by said dividing means; conversion means for converting, by referring to said conversion tables, multi-level image data of a pixel of each pixel block obtained by division by said dividing means, into data corresponding to that pixel in the pixel block; and quantization means for quantizing the data corresponding to the pixel in the pixel block produced by said conversion means, wherein each item of the conversion data of each of said conversion tables has been set in such a manner that an average value of the data corresponding to the pixel in the pixel block converted by said conversion means, takes on a value that is based on the multilevel image data within the block.

Claim 3

The apparatus according to claim 1 , wherein each item of the conversion data is data for converting luminance data to density data.

Claim 4

The apparatus according to claim 1 , wherein each item of the conversion data is data for converting density data in accordance with image formation characteristics of an image forming apparatus that forms an image based upon the data converted by said conversion means.

Claim 5

The apparatus according to claim 1 , wherein the conversion tables output the data upon having the multilevel image data input thereto, and wherein the data differs depending upon the position even if the multilevel image data is same.

Claim 6

An image processing method for processing multilevel image data, comprising: a dividing step, of dividing the multilevel image data into pixel blocks each comprising a plurality of pixels; a conversion step, of converting multilevel image data of a pixel of each pixel block obtained by division, by referring to conversion tables having a plurality of items of conversion data, each corresponding to each pixel position in each pixel block obtained by division in said dividing step, into data corresponding to that pixel in the block; and a quantizing step, of quantizing the data corresponding to the pixel in the pixel block produced in said conversion step, wherein each item of the conversion data of each of the conversion tables has been set in such a manner that an average value of the data corresponding to pixel in the pixel block converted in said conversion step, takes on a value that is based on corresponding multi-level image data within the pixel block.

Claim 7

An image processing method for processing multilevel image data, comprising: a dividing step, of dividing the multilevel image data into pixel blocks each comprising a plurality of pixels; a conversion step, of converting multilevel image data of a pixel of each pixel block obtained by division, by referring to conversion tables having a plurality of items of conversion data, each corresponding to each pixel position in each pixel block obtained by division in said dividing step, into data corresponding to that pixel in the block; and a quantizing step, of quantizing the data corresponding to the pixel in the pixel block produced in said conversion step, wherein each item of the conversion data of each of the conversion tables has been set in such a manner that an average value of the data corresponding to pixel in the pixel block converted in said conversion step, takes on a value that is based on corresponding multi-level image data within the pixel block.

Claim 8

The method according to claim 5 , wherein each item of the conversion data is data for converting luminance data to density data.

Claim 9

The method according to claim 5 , wherein each item of the conversion data is data for converting density data in accordance with image formation characteristics of an image forming apparatus that forms an image based upon the data converted in said conversion step.

Claim 10

The method according to claim 5 , wherein the conversion tables output the data upon having the multilevel image data input thereto as an address, and wherein the data differs depending upon the position even if the address is the same.

Claim 11

A computer-readable storage medium storing a control program for executing the image processing set forth in claim 5 .

Claim 12

A printing control apparatus to which multilevel image data is input for generating printing data to control an image printing apparatus, comprising: dividing means for dividing the multilevel image data into pixel blocks each comprising a plurality of pixels; conversion tables having a plurality of items of conversion data, each item corresponding to a pixel position in each pixel block obtained by division by said dividing means; conversion means for converting, by referring to said conversion tables, multilevel image data of a pixel of each pixel block obtained by division by said dividing means, into data corresponding to that pixel in the pixel block; and print-data generating means for generating print data, which is for being printed by said image printing apparatus, based upon the data converted by said conversion means, said print-data generating means including quantization means for quantizing the data corresponding to pixel in the pixel in the pixel block produced by said conversion means, wherein each item of the conversion data of each of said conversion tables has been set in such a manner that an average value of the data corresponding to the pixel in the pixel block converted by said conversion means, takes on a value that is based on the multilevel image data within the pixel block.

Claim 13

A printing control apparatus to which multilevel image data is input for generating printing data to control an image printing apparatus, comprising: dividing means for dividing the multilevel image data into pixel blocks each comprising a plurality of pixels; conversion tables having a plurality of items of conversion data, each item corresponding to a pixel position in each pixel block obtained by division by said dividing means; conversion means for converting, by referring to said conversion tables, multilevel image data of a pixel of each pixel block obtained by division by said dividing means, into data corresponding to that pixel in the pixel block; and print-data generating means for generating print data, which is for being printed by said image printing apparatus, based upon the data converted by said conversion means, said print-data generating means including quantization means for quantizing the data corresponding to pixel in the pixel in the pixel block produced by said conversion means, wherein each item of the conversion data of each of said conversion tables has been set in such a manner that an average value of the data corresponding to the pixel in the pixel block converted by said conversion means, takes on a value that is based on the multilevel image data within the pixel block.

Claim 14

The apparatus according to claim 10 , wherein each item of the conversion data is data for converting luminance data to density data.

Claim 15

The apparatus according to claim 10 , wherein each item of the conversion data is data for converting density data in accordance with image formation characteristics of an image forming apparatus that forms an image based upon the data corresponding to pixel data converted by said conversion means.

Claim 16

The apparatus according to claim 10 , wherein the conversion tables output the data upon having the multilevel image data input thereto, and wherein the data differs depending upon the position even if the multilevel image data are the same.

Claim 17

A printing control method for inputting multilevel image data and generating print data to control an image printing apparatus, comprising: a dividing step, of dividing the multilevel image data into pixel blocks each comprising a plurality of pixels; a conversion step, of converting multilevel image data of a pixel of each pixel block obtained by division, by referring to conversion tables having a plurality of items of conversion data, each corresponding to each pixel position in each pixel block obtained by division in said dividing step, into data corresponding to that pixel in a pixel block; and a print-data generating step, of generating print data, which is for being printed by said image printing apparatus, based upon the data produced in said conversion step, said print-data generating step including a quantization step of quantizing the data corresponding to the pixel in the pixel block produced in said conversion step, wherein each item of the conversion data of each of the conversion tables has been set in such a manner that an average value of the data corresponding to the pixel in the pixel block converted in said conversion step, takes on a value that is based on multilevel image data within the pixel block.

Claim 18

A printing control method for inputting multilevel image data and generating print data to control an image printing apparatus, comprising: a dividing step, of dividing the multilevel image data into pixel blocks each comprising a plurality of pixels; a conversion step, of converting multilevel image data of a pixel of each pixel block obtained by division, by referring to conversion tables having a plurality of items of conversion data, each corresponding to each pixel position in each pixel block obtained by division in said dividing step, into data corresponding to that pixel in a pixel block; and a print-data generating step, of generating print data, which is for being printed by said image printing apparatus, based upon the data produced in said conversion step, said print-data generating step including a quantization step of quantizing the data corresponding to the pixel in the pixel block produced in said conversion step, wherein each item of the conversion data of each of the conversion tables has been set in such a manner that an average value of the data corresponding to the pixel in the pixel block converted in said conversion step, takes on a value that is based on multilevel image data within the pixel block.

Claim 19

The method according to claim 14 , wherein each item of the conversion data is data for converting luminance data to density data.

Claim 20

The method according to claim 14 , wherein each item of the conversion data is data for converting density data in accordance with image formation characteristics of an image forming apparatus that forms an image based upon the data produced in said conversion step.

Claim 21

The method according to claim 14 , wherein the conversion tables output the data having the multilevel image data input thereto as an address, and wherein the data differs depending upon the position even if the address is the same.

Claim 22

A computer-readable storage medium storing a control program for executing the recording control method set forth in claim 14 .

Claim 23

A printer driver to which multilevel image data is input for generating print data, comprising: a module of a dividing step of dividing the multilevel image data into pixel blocks each comprising a plurality of pixels; a module of a conversion step of converting multilevel image data of a pixel of each pixel block obtained by division, by referring to conversion tables having a plurality of items of conversion data, each corresponding to each pixel position in each pixel block obtained by division by said module of the dividing step; and a module of a print-data generating step of generating print data, which is for being printed by the image printing apparatus, based upon the data produced by said module of the conversion step, the print-data generating step including a quantization step of quantizing the data corresponding to pixel in the pixel block produced by said module of the converting step, wherein each item of the conversion data of each of the conversion tables has been set in such a manner that an average value of the data corresponding to the pixel in the pixel block converted by the module of the conversion step, takes on a value that is based on the multilevel image data within the pixel block.

Claim 24

A printer driver to which multilevel image data is input for generating print data, comprising: a module of a dividing step of dividing the multilevel image data into pixel blocks each comprising a plurality of pixels; a module of a conversion step of converting multilevel image data of a pixel of each pixel block obtained by division, by referring to conversion tables having a plurality of items of conversion data, each corresponding to each pixel position in each pixel block obtained by division by said module of the dividing step; and a module of a print-data generating step of generating print data, which is for being printed by the image printing apparatus, based upon the data produced by said module of the conversion step, the print-data generating step including a quantization step of quantizing the data corresponding to pixel in the pixel block produced by said module of the converting step, wherein each item of the conversion data of each of the conversion tables has been set in such a manner that an average value of the data corresponding to the pixel in the pixel block converted by the module of the conversion step, takes on a value that is based on the multilevel image data within the pixel block.

Claim 25

The printer driver according to claim 19 , wherein each item of the conversion data is data for converting luminance data to density data.

Claim 26

The printer driver according to claim 19 , wherein each item of the conversion data is data for converting density data in accordance with image formation characteristics of an image forming apparatus that forms an image based upon the data converted by the module of the conversion step.

Claim 27

The printer driver according to claim 19 , wherein the conversion tables output the data upon having the multilevel image data input thereto as an address, and wherein the data differs depending upon the position even if the address is the same.

Claim 28

A computer-readable storage medium storing software for performing the functions of the printer driver set forth in claim 19 .