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US6945626B2 Expired / Lapsed US ⏱️ 0.0 years remaining

Correction table generation method and method of controlling correction table generation apparatus

Assignee: Canon Inc
•
Filing: 2003-09-08
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Granted: 2005-09-20
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Expires: 2023-09-08
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Abstract

Abstract In a multi-valued printer that uses discontinuous index patterns, if a tone correction table is generated using sampled density patches, a table which is different from a table to be obtained and has no inflection point is obtained, and the print density characteristics after tone correction suffer discontinuity. To solve this problem, an output gamma table used to output measurement patches is set to linearly correct the printer print characteristics. Patches are output and their densities are measured. A reverse table of a “signal value—density” table is generated, and is smoothed using a recursive curve. The smoothed reverse table is finely adjusted to generate an intermediate output gamma table. The generated table undergoes index component correction, thus generating a tone correction table.

Inventors

  • 👤 Okinori Tsuchiya
  • 👤 Shigeyasu Nagoshi
  • 👤 Akihiko Nakatani

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 11:01
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/56; H04N1/60; H04N1/6097; H04N1/40; H04N1/40087; H04N1/407; H04N1/603; H04N1/6033

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 78 words
A generation method of generating a correction table used to correct print characteristics of a printing apparatus which has nonlinear characteristics between an input signal and a print signal to be output in accordance with the input signal, said method comprising step of: generating, on the basis of a first tone correction table which is generated while compensating for the nonlinear characteristics, a second tone correction table having a maximum value different from the first tone correction table.
Claim 2
Dependent Claim 78 words
A generation method of generating a correction table used to correct print characteristics of a printing apparatus which has nonlinear characteristics between an input signal and a print signal to be output in accordance with the input signal, said method comprising step of: generating, on the basis of a first tone correction table which is generated while compensating for the nonlinear characteristics, a second tone correction table having a maximum value different from the first tone correction table.
Claim 3
Dependent Claim 35 words
A method according to claim 1 , wherein the second tone correction table is generated on the basis of an input image signal to the printing apparatus and print density characteristics of the printing apparatus.
Claim 4
Dependent Claim 48 words
A method according to claim 1 , wherein the second tone correction table is generated on the basis of a table, which is generated from a table corresponding to the nonlinear characteristics while compensating for the nonlinear characteristics, to have the first tone correction table as an input.
Claim 5
Dependent Claim 36 words
A method according to claim 1 , wherein the second tone correction table is generated on the basis of a table which is obtained by variably scaling tone correction values of the first tone correction table.
Claim 6
Dependent Claim 38 words
A method according to claim 1 , wherein the second tone correction table is used to correct a dot quantity of a print material of a print medium in consideration of an acceptable quantity of the print material.
Claim 7
Dependent Claim 83 words
A control method of generating a correction table used to correct print characteristics of a printing apparatus which has nonlinear characteristics between an input signal and a print signal to be output in accordance with the input signal, said method comprising steps of: setting a first tone correction table generated while compensating for the nonlinear characteristics; and generating a second tone correction table having a maximum value different from the first tone correction table on the basis of the first tone correction table.
Claim 8
Dependent Claim 83 words
A control method of generating a correction table used to correct print characteristics of a printing apparatus which has nonlinear characteristics between an input signal and a print signal to be output in accordance with the input signal, said method comprising steps of: setting a first tone correction table generated while compensating for the nonlinear characteristics; and generating a second tone correction table having a maximum value different from the first tone correction table on the basis of the first tone correction table.
Claim 9
Dependent Claim 89 words
A computer program embodied on a computer-readable storage medium executing a generation method of generating a correction table used to correct print characteristics of a printing apparatus which has nonlinear characteristics between an input signal and a print signal to be output in accordance with the input signal, said computer program comprising: code for generating, on the basis of a first tone correction table which is generated while compensating for the nonlinear characteristics, a second tone correction table having a maximum value different from the first tone correction table.
Claim 10
Dependent Claim 89 words
A computer program embodied on a computer-readable storage medium executing a generation method of generating a correction table used to correct print characteristics of a printing apparatus which has nonlinear characteristics between an input signal and a print signal to be output in accordance with the input signal, said computer program comprising: code for generating, on the basis of a first tone correction table which is generated while compensating for the nonlinear characteristics, a second tone correction table having a maximum value different from the first tone correction table.
Claim 11
Dependent Claim 89 words
A computer readable medium storing a computer program for executing a generation method of generating a correction table used to correct print characteristics of a printing apparatus which has nonlinear characteristics between an input signal and a print signal to be output in accordance with the input signal, said computer program comprising: code for generating, on the basis of a first tone correction table which is generated while compensating for the nonlinear characteristics, a second tone correction table having a maximum value different from the first tone correction table.
Claim 12
Dependent Claim 89 words
A computer readable medium storing a computer program for executing a generation method of generating a correction table used to correct print characteristics of a printing apparatus which has nonlinear characteristics between an input signal and a print signal to be output in accordance with the input signal, said computer program comprising: code for generating, on the basis of a first tone correction table which is generated while compensating for the nonlinear characteristics, a second tone correction table having a maximum value different from the first tone correction table.

References Cited (Backward Citations)

JPH082659B2 Cited
JPH02167755A Cited
JPH0946522A Cited
US6203133B1 Cited
US6832825B1 Cited
US20010007599A1 Cited
US20020048031A1 Cited
US20020154326A1 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2008-09-19 2009-03-21 2009-09-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2012-09-19 2013-03-21 2013-09-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2016-09-19 2017-03-21 2017-09-20 $7700.00 Window Closed / Lapsed

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