Method of any apparatus for converting gradient of image data

Claim 1

A method of converting the gradient of image data, comprising the steps of: converting N-bit input image data having a number of density steps A to M-bit image data; processing said M-bit input data with K-bit random-number data (M≧K) having an integer part to produce image data; and after performing said processing step, extracting high-order L bits {L>(M-K)} of the image data, produced by the processing step, as output image data having a number of density steps A which is equal to the number of density steps A of the input image data, or a number of density steps B which is different from the number of density steps A of the input image data, wherein at least a portion of said extracted L-bits has been generated by said integer part of said K-bit random number data directly operating on a portion of said M-bit image data.

Claim 2

A method of converting the gradient of image data, comprising the steps of: converting N-bit input image data having a number of density steps A to M-bit image data; processing said M-bit input data with K-bit random-number data (M≧K) having an integer part to produce image data; and after performing said processing step, extracting high-order L bits {L>(M-K)} of the image data, produced by the processing step, as output image data having a number of density steps A which is equal to the number of density steps A of the input image data, or a number of density steps B which is different from the number of density steps A of the input image data, wherein at least a portion of said extracted L-bits has been generated by said integer part of said K-bit random number data directly operating on a portion of said M-bit image data.

Claim 3

An apparatus for converting the gradient of image data, comprising: storage means for holding a gradient conversion table for converting N-bit input image data having a number of density steps A to M-bit image data; random-number generating means for generating K-bit random-number data (M≧K) having an integer part; processing means for processing said M-bit image data with the K-bit random-number data to produce image data; and extracting means for extracting high-order L bits {L>(M-K)} of the image data, produced by said processing means, as output image data having a number of density steps A which is equal to the number of density steps A of the input image data, or a number of density steps B which is different from the number of density steps A of the input image data, wherein at least a portion of said extracted L-bits has been generated by said integer part of said K-bit random number data directly operating on a portion of said M-bit image data.

Claim 4

An apparatus for converting the gradient of image data, comprising: storage means for holding a gradient conversion table for converting N-bit input image data having a number of density steps A to M-bit image data; random-number generating means for generating K-bit random-number data (M≧K) having an integer part; processing means for processing said M-bit image data with the K-bit random-number data to produce image data; and extracting means for extracting high-order L bits {L>(M-K)} of the image data, produced by said processing means, as output image data having a number of density steps A which is equal to the number of density steps A of the input image data, or a number of density steps B which is different from the number of density steps A of the input image data, wherein at least a portion of said extracted L-bits has been generated by said integer part of said K-bit random number data directly operating on a portion of said M-bit image data.

Claim 5

A method of converting the gradient of image data, comprising the steps of: converting N-bit input image data having a number of density steps A to M-bit image data; processing said M-bit input data with K-bit random-number data (M>K) having no integer part to produce image data; and after performing said processing step, extracting high-order L bits {L=(M-K)} of the image data, produced by the processing step, as output image data having a number of density steps B which is different from the number of density steps A of the input image data.

Claim 6

A method of converting the gradient of image data, comprising the steps of: converting N-bit input image data having a number of density steps A to M-bit image data; processing said M-bit input data with K-bit random-number data (M>K) having no integer part to produce image data; and after performing said processing step, extracting high-order L bits {L=(M-K)} of the image data, produced by the processing step, as output image data having a number of density steps B which is different from the number of density steps A of the input image data.

Claim 7

An apparatus for converting the gradient of image data, comprising: storage means for holding a gradient conversion table for converting N-bit input image data having a number of density steps A to M-bit image data; random-number generating means for generating K-bit random-number data (M>K) having no integer part; processing means for processing said M-bit image data with the K-bit random-number data to produce image data; and extracting means for extracting high-order L bits {L=(M-K)} of the image data, produced by said processing means, as output image data having a number of density steps B which is different from the number of density steps A of the input image data.

Claim 8

An apparatus for converting the gradient of image data, comprising: storage means for holding a gradient conversion table for converting N-bit input image data having a number of density steps A to M-bit image data; random-number generating means for generating K-bit random-number data (M>K) having no integer part; processing means for processing said M-bit image data with the K-bit random-number data to produce image data; and extracting means for extracting high-order L bits {L=(M-K)} of the image data, produced by said processing means, as output image data having a number of density steps B which is different from the number of density steps A of the input image data.

Claim 9

A method of converting the gradient of image data, comprising the steps of: converting N-bit input image data having a number of density steps A to M-bit image data; processing said M-bit image data with K-bit random-number data (M≧K) having an integer part to produce image data; and after performing said processing step, extracting high-order L-bits {L>(M-K)} of the image data, produced by said processing step, as output image having a number of density steps B which is different from the number of density steps A of the input image data, wherein at least a portion of said extracted L-bits has been generated by said integer part of said K-bit random number data directly operating on a portion of said M-bit image data.

Claim 10

A method of converting the gradient of image data, comprising the steps of: converting N-bit input image data having a number of density steps A to M-bit image data; processing said M-bit image data with K-bit random-number data (M≧K) having an integer part to produce image data; and after performing said processing step, extracting high-order L-bits {L>(M-K)} of the image data, produced by said processing step, as output image having a number of density steps B which is different from the number of density steps A of the input image data, wherein at least a portion of said extracted L-bits has been generated by said integer part of said K-bit random number data directly operating on a portion of said M-bit image data.

Claim 11

An apparatus for converting the gradient of image data, comprising: storage means for holding a gradient conversion table for converting N-bit input image data having a number of density steps A to M-bit image data; random-number generating means for generating K-bit random-number data (M≧K) having an integer part; processing means for processing said M-bit image data with the K-bit random-number data to produce image data; and extracting means for extracting high-order L bits {L>(M-K)} of the image data, produced by said processing means, as output image data having a number of density steps B which is different from the number of density steps A of the input image data, wherein at least a portion of said extracted L-bits has been generated by said integer part of said K-bit random number data directly operating on a portion of said M-bit image data.

Claim 12

An apparatus for converting the gradient of image data, comprising: storage means for holding a gradient conversion table for converting N-bit input image data having a number of density steps A to M-bit image data; random-number generating means for generating K-bit random-number data (M≧K) having an integer part; processing means for processing said M-bit image data with the K-bit random-number data to produce image data; and extracting means for extracting high-order L bits {L>(M-K)} of the image data, produced by said processing means, as output image data having a number of density steps B which is different from the number of density steps A of the input image data, wherein at least a portion of said extracted L-bits has been generated by said integer part of said K-bit random number data directly operating on a portion of said M-bit image data.

Claim 25

An apparatus for converting the gradient of image data, comprising: an input interface which receives input image data; an input buffer which temporarily stores the input image data output from the input interface; a density converter which converts, based on a predetermined resolution characteristic, the density of the input image data output from the input buffer and provides density converted image data; a storage device which stores a gradient conversion table which converts said density converted image data, provided from said density converter and having a number of density steps A, into M-bit image data; a random-number generator which generates K-bit random-number data (M≧K) having an integer part; a processor which processes said M-bit image data with the K-bit random-number data to produce image data; and an extracting device which extracts high-order L bits {L>(M-K)} of the image data, produced by said processor, as output image data having a number of density steps A which is equal to the number of density steps A of the input image data, or a number of density steps B which is different from the number of density steps A of the input image data, wherein at least a portion of said extracted L-bits has been generated by said integer part of said K-bit random number data directly operating on a portion of said M-bit image data; a halftone-dot signal generator which generates a halftone-dot signal based on the output image data; an output buffer which temporarily stores the halftone-dot signal; and an output interface which supplies said halftone-dot signal from said output buffer to an image output device having the predetermined resolution characteristic.

Claim 26

An apparatus for converting the gradient of image data, comprising: an input interface which receives input image data; an input buffer which temporarily stores the input image data output from the input interface; a density converter which converts, based on a predetermined resolution characteristic, the density of the input image data output from the input buffer and provides density converted image data; a storage device which stores a gradient conversion table which converts said density converted image data, provided from said density converter and having a number of density steps A, into M-bit image data; a random-number generator which generates K-bit random-number data (M≧K) having an integer part; a processor which processes said M-bit image data with the K-bit random-number data to produce image data; and an extracting device which extracts high-order L bits {L>(M-K)} of the image data, produced by said processor, as output image data having a number of density steps A which is equal to the number of density steps A of the input image data, or a number of density steps B which is different from the number of density steps A of the input image data, wherein at least a portion of said extracted L-bits has been generated by said integer part of said K-bit random number data directly operating on a portion of said M-bit image data; a halftone-dot signal generator which generates a halftone-dot signal based on the output image data; an output buffer which temporarily stores the halftone-dot signal; and an output interface which supplies said halftone-dot signal from said output buffer to an image output device having the predetermined resolution characteristic.