US5953498A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nonliner calibration of output devices
Assignee: Professional Software Technologies Inc
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Filing: 1997-05-02
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Granted: 1999-09-14
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Expires: 2017-05-02
Abstract
Abstract A method for the nonlinear calibration of digital image data without the introduction of tonal loss is applied to image data in a computer-to-printing press system. Apparatus for implementing this method is provided. Computer processed graphics, provided from the computer in 8-bit format, are converted into 16-bit format. This 16-bit image data is then calibrated to compensate for anticipated press gain. The calibration translates the image data according to a desired nonlinear cutback (value reduction) curve of gray value reduction. Calibrated image data is then passed through 16-bit halftoning screening, the output from which is provided to the imagesetter. The implemention may include a general purpose computer with specific software resident therein, or dedicated hardware including a series of encoders and look-up table implementaion devices. Alternatively, or supplementally, the laser exposure in the image setter may be increased to contribute substitute or supplemental analog nonlinear gray value reduction.
Inventors
- 👤 Mark R. Samworth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:38
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/407
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
128 words
A method of calibrating the output for an imagesetter in a printing system, having an 8-bit source of continuous gray value image data, an imagesetter which previously directly received said image data and a press fed from said imagesetter, which press requires the calibration of the imagesetter operation to compensate for press gain, consisting of the steps of: obtaining said 8-bit gray value image data; converting said 8-bit gray value image data obtained in to 16-bit format; establishing a target curve for reducing each individual gray value of said converted image data prior to sending said value to the imagesetter; calibrating said converted 16-bit image data to said target curve; halftone 16-bit screening said calibrated 16-bit image data; and providing said halftone screened image data to said imagesetter.
Claim 2
Independent Claim
128 words
A method of calibrating the output for an imagesetter in a printing system, having an 8-bit source of continuous gray value image data, an imagesetter which previously directly received said image data and a press fed from said imagesetter, which press requires the calibration of the imagesetter operation to compensate for press gain, consisting of the steps of: obtaining said 8-bit gray value image data; converting said 8-bit gray value image data obtained in to 16-bit format; establishing a target curve for reducing each individual gray value of said converted image data prior to sending said value to the imagesetter; calibrating said converted 16-bit image data to said target curve; halftone 16-bit screening said calibrated 16-bit image data; and providing said halftone screened image data to said imagesetter.
Claim 3
Dependent Claim
47 words
The method of claim 1, wherein after the step of 16-bit screening there is included the step of: adjusting the exposure intensity of said imagesetter to attenuate gray tone image data values processed by said imagesetter, said exposure adjusting step being performed prior to said providing step.
Claim 4
Independent Claim
193 words
An apparatus for providing calibrated imagesetter output to a printing press, for compensating for press gain digital dot imaging and for calibrating to eliminate 8-bit tonal loss at the press, comprising: a buffer circuit connected to receive 8-bit digital image data from a desktop publishing type computer; a conversion circuit connected to said buffer circuit for converting said digital image data from 8-bit image data to 16-bit image data; a 16-bit calibration processor circuit connected to receive said 16-bit image data from said conversion circuit, said calibration processor reducing the gray values of said image data according to a cutback calibration curve; a first memory connected to said calibration processor circuit for holding a look-up table defining a cutback calibration curve used by said calibration processor circuit; a second memory connected to said first memory for holding a library of different cutback calibration curves, individually selectable for loading into the look-up table of said first memory; and a 16-bit halftone screening processor connected to receive the calibrated image data from said calibration processor circuit for halftone screening said calibrated image data; wherein said halftone screening processor can provide an output to said imagesetter.
Claim 5
Independent Claim
193 words
An apparatus for providing calibrated imagesetter output to a printing press, for compensating for press gain digital dot imaging and for calibrating to eliminate 8-bit tonal loss at the press, comprising: a buffer circuit connected to receive 8-bit digital image data from a desktop publishing type computer; a conversion circuit connected to said buffer circuit for converting said digital image data from 8-bit image data to 16-bit image data; a 16-bit calibration processor circuit connected to receive said 16-bit image data from said conversion circuit, said calibration processor reducing the gray values of said image data according to a cutback calibration curve; a first memory connected to said calibration processor circuit for holding a look-up table defining a cutback calibration curve used by said calibration processor circuit; a second memory connected to said first memory for holding a library of different cutback calibration curves, individually selectable for loading into the look-up table of said first memory; and a 16-bit halftone screening processor connected to receive the calibrated image data from said calibration processor circuit for halftone screening said calibrated image data; wherein said halftone screening processor can provide an output to said imagesetter.
Claim 6
Dependent Claim
88 words
A process for calibrating gray tone digital image data for an imagesetter without significant tonal loss, consisting of the steps of: receiving 8-bit gray tone image data; converting said 8-bit gray tone image data to 16-bit gray tone data; calibrating said 16-bit gray tone image data to a cutback curve to compensate for digital format press gain which said imagesetter is not capable of compensating for; halftone screening said calibrated 16-bit image data; and passing said 16-bit halftone screened and calibrated image data gray values to said imagesetter.
Claim 7
Dependent Claim
88 words
A process for calibrating gray tone digital image data for an imagesetter without significant tonal loss, consisting of the steps of: receiving 8-bit gray tone image data; converting said 8-bit gray tone image data to 16-bit gray tone data; calibrating said 16-bit gray tone image data to a cutback curve to compensate for digital format press gain which said imagesetter is not capable of compensating for; halftone screening said calibrated 16-bit image data; and passing said 16-bit halftone screened and calibrated image data gray values to said imagesetter.
Claim 8
Dependent Claim
41 words
The method of claim 4, wherein after the step of halftone screening and before the step of passing is performed the step of: adjusting the exposure intensity of said imagesetter to attenuate gray tone image data values processed by said imagesetter.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-09-13 | 2003-03-15 | 2003-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-09-13 | 2007-03-15 | 2007-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-09-13 | 2011-03-15 | 2011-09-14 | $7700.00 | Window Closed / Lapsed |