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EP0949807A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Transforms for digital images

Assignee: Eastman Kodak Co
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Filing: 1999-03-29
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Granted: —
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Expires: 2019-03-29
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Abstract

Abstract A method for selecting an aim curve for a desired medium having a predetermined maximum density, including selecting an aim curve from a family of aim curves for a different medium having a lower predetermined maximum density than that of the desired medium, the aim curve having shadow, midtone, and highlight regions; varying the shadow contrast in the shadow region of the selected aim curve to produce a different aim curve; and determining the different aim curve with the desired medium that has an improved shadow contrast that will produce prints with reduced flare and permits a better fit of the dynamic range of the original scene to the dynamic range of the medium. <IMAGE>

Inventors

  • 👤 Paul B. Gilman
  • 👤 John F. Hamilton, Jr.
  • 👤 Richard M. Vogel

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-09 12:25
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/56; H04N1/60; H04N1/6027; H04N1/6083; H04N1/6086; H04N1/6088; H04N1/6097

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 120 words
A method for selecting an aim curve for a desired medium having a predetermined maximum density, comprising the steps of: a) selecting an aim curve from a family of aim curves for a different medium having a lower predetermined maximum density than that of the desired medium, the aim curve having shadow, midtone, and highlight regions; b) varying the shadow contrast in the shadow region of the selected aim curve to produce a different aim curve; and c) determining the different aim curve with the desired medium that has an improved shadow contrast that will produce prints with reduced flare and permits a better fit of the dynamic range of the original scene to the dynamic range of the medium.
Claim 2
Independent Claim 227 words
A method for constructing a transform for a predetermined display or printer, such printer or display being adapted to form a black and white or color image, on a particular medium, the input to the transform being a digital image file produced by a particular image capture device, comprising the steps of: a) providing an input characteristic curve which is a function of the output color code values from the image capture device and relative log exposure of the scene; b) providing an aim curve which is a function of the visual density of the display or medium and the image capture relative log exposure wherein the mid region of the aim curve is in a range of contrasts from between 1.00 and 1.30 at a relative log exposure of 0.6 above scene white to a contrast of between 1.0 and 1.7 at a relative log exposure of 1.45 above scene white and at the upper scale region of the aim curve plotted as density vs. relative log E wherein the aim curve is satisfied by transforming log exposure into print density composed with a boost function which modifies the print density to achieve the desired aim curve that has an upper scale contrast which minimizes flare and permits a better fit of the dynamic range of the original scene to the dynamic range of the medium.
Claim 3
Dependent Claim 23 words
The method of claim 2 wherein the transform is selected to have points between Dmin and Dmax which produce an esthetically pleasing print.
Claim 4
Dependent Claim 22 words
The method of claim 2 wherein the contrast of the shoulder of the aim curve is gradually increased to reduce viewing flare.
Claim 5
Dependent Claim 13 words
The method of claim 1 wherein, when the transform is for a printer.
Claim 6
Dependent Claim 23 words
The method of claim 5 wherein the image capture device is a digital camera and the particular medium is a thermal print medium.
Claim 7
Dependent Claim 13 words
The method of claim 5 wherein the printer is an ink jet printer.
Claim 8
Dependent Claim 12 words
The method of claim 5 wherein the printer is an electrophotographic printer.
Claim 9
Independent Claim 289 words
A method for constructing a transform for a predetermined display or printer, such printer or display being adapted to form a black and white or color image, on a particular medium, the input to the transform being a digital image file produced by a particular image capture device, comprising the steps of: a) providing an input characteristic curve which is a function of the output color code values from the image capture device and relative log exposure of the scene; b) providing an aim curve which is a function of the visual density of the display or medium and the image capture relative log exposure wherein the mid region of the aim curve is in a range of contrasts from between 1.00 and 1.30 at a relative log exposure of 0.6 above scene white to a contrast of between 1.0 and 1.7 at a relative log exposure of 1.45 above scene white and at the upper scale region of the aim curve plotted as density vs. relative log E wherein substantially satisfying the following relationship: G(x) = F(x) + B(F(x)) wherein: F(x) is a conventional tone reproduction scale and wherein x is log exposure; and B(F(x)) is a boost function which satisfies the relationship: in which: y denotes any print density; y 0 denotes a particular print density;  denotes a particular angle of inclination; and h denotes a particular small increment of print density; c) providing an output characteristic curve which is a function of the input color code values to the predetermined display or printer and the visual density from a display or print on a particular medium; and d) using the aim curve, the input characteristic curve, and the output characteristic curve to produce the transform.
Claim 10
Dependent Claim 193 words
A computer program product comprising a computer readable storage medium, including a transform made by the steps of: a) providing an input characteristic curve which is a function of the output color code values from the image capture device and relative log exposure of the scene; b) providing an aim curve which is a function of the visual density of the display or medium and the image capture relative log exposure wherein the mid region of the aim curve is in a range of contrasts from between 1.00 and 1.30 at a relative log exposure of 0.6 above scene white to a contrast of between 1.0 and 1.7 at a relative log exposure of 1.45 above scene white and at the upper scale region of the aim curve plotted as density vs. relative log E wherein the aim curve is developed by transforming log exposure into print density composed with a boost function which modifies the print density to achieve the desired aim curve that has an upper scale contrast which minimizes flare and permits a better fit of the dynamic range of the original scene to the dynamic range of the medium.

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