Colour correction system and method

Claim 2

A colour correction system for correcting a set of three-colour gradation input data, wherein each data item has a length of m-bits, to produce a set of corrected three colour gradation data, wherein each data item has a length of m-bits, characterised by memory means (31) for storing previously calculated sets of corrected colour gradation data in a three dimensional co-ordinate arrangement, wherein each co-­ordinate location is designated by a respective set of n-bit address data, n being less than m, means (11, 61) for generating co-ordinate selection data from the least significant (m - n) bits in a set of colour gradation input data, means (21 to 23) operable in response to the most significant n-bits of the set of colour gradation input data and the co-ordinate selection data for generating sets of n-bit address data to cause the memory means to output selected sets of corrected colour gradation data, and means (41, 51) for receiving the selected sets of corrected colour gradation data and for calculating averages thereof for output.

Claim 3

A system according to claim 1 characterised in that the means for generating the co-ordinate selection data comprise further memory means (11) for pre-storing the co-ordinate selection data, the further memory means being arranged in response to the least significant (m - n) bits of colour gradation input data consecutively to produce respective sets of three co-ordinate selection data values, and in that the means for generating the sets of n-bit address data comprise adding means (21 to 23) for consecutively receiving the respective sets of co-ordinate selection data values and for adding the same to the most significant n-bits of the set of colour gradation input data for consecutively generating the sets of n-bit address data.

Claim 4

A system according to claim 1 or 2 characterised in that the means for calculating averages are arranged consecutively to receive and hold the sets of corrected colour gradation data.

Claim 5

A system according to claim 3 characterised in that the means for calculating averages comprise a plurality of registers (41 to 44), and an adding circuit (51).

Claim 7

A system according to claim 2 characterised in that the memory means for storing the previously calculated sets of corrected colour gradation data has a capacity of at least 2 3xn x 3 bytes, and in that the further memory means has a capacity of at least 2 m-n x 3 bytes.

Claim 8

A system according to claim 2 or 6 characterised in that the memory means for storing the previously calculated sets of corrected colour gradation data and the further memory means are incorporated as a single memory means.

Claim 11

A system according to any of claims 1 to 7 or a method according to claim 8 characterised in that the three colour gradation data represents gradation data for cyan, magenta and yellow.

Claim 12

A system according to any of claims 1 to 7 or a method according to claim 8 characterised in that the three colour gradation data represents gradation data for red, green and blue.

Claim 13

A colour correction system for correcting three kinds of colour gradation input data, each having an m-­bit length, to produce three kinds of corrected colour gradation data each having an m-bit length, charac­terised by first memory means (31) for storing previously calculated colour gradation corrected data arranged in a three dimensional co-ordinate space and defined by a combination of upper n-bits colour gradation data where m is greater than n; second memory means (11) for storing previously obtained co-ordinate correction data defined by a combination of lower (m - n) bits colour gradation data, and outputting a first to a third co-ordinate correction data in response to the lower bits colour gradation data; adding means (21 to 23) for adding said upper n-bits data of said first to third colour gradation input data and said first to third co-ordinate correction data output from said second memory means and outputting same to said first memory means as a memory address thereof, to cause an output of said stored colour gradation corrected data defined by said memory address from said first memory means; and average calculating means (41, 51) receiving said colour gradation corrected data from said first memory means and calculating averages of said three kinds of colour gradation corrected data.

Claim 14

A colour correction system for correcting three kinds of colour gradation input data, each having an m-­bit length, to produce three kinds of corrected colour gradation data each having an m-bit length, charac­terised by first memory means (31) for storing previously calculated colour gradation corrected data arranged in a three dimensional co-ordinate space and defined by a combination of upper n-bits colour gradation data where m is greater than n; second memory means (11) for storing previously obtained co-ordinate correction data defined by a combination of lower (m - n) bits colour gradation data, and outputting a first to a third co-ordinate correction data in response to the lower bits colour gradation data; adding means (21 to 23) for adding said upper n-bits data of said first to third colour gradation input data and said first to third co-ordinate correction data output from said second memory means and outputting same to said first memory means as a memory address thereof, to cause an output of said stored colour gradation corrected data defined by said memory address from said first memory means; and average calculating means (41, 51) receiving said colour gradation corrected data from said first memory means and calculating averages of said three kinds of colour gradation corrected data.