EP0741492B1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Selective colour correction applied to plurality of local color gamuts
Assignee: Agfa Gevaert NV
•
Filing: 1996-04-03
•
Granted: 1999-03-03
•
Expires: 2016-04-03
Abstract
No abstract record available.
Inventors
- 👤 Chris Tuijn
- 👤 Earle Stokes
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 19:19
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/56; H04N1/60; H04N1/62; H04N1/622
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
108 words
A method for selective correction of an original colour x in
an original colour image, comprising the steps of : selecting at least two different colours µ K , K=1,..N, N≥2; defining for each selected colour µ K a required colour
change δ K ; defining for each selected colour µ K a weighting function
W K ( x ) ; and, applying a colour modification to said original colour x ,
according to Σ K W K ( x ) δ K , K=1,..N is characterised in that W K ( µ J ) = 0 if K≠J and W K ( µ K ) = 1.
Claim 2
Dependent Claim
24 words
Method according to claim 1, wherein each weighting function
obeys the following inequalities in its range of definition :
0≤W K ( x )≤1.
Claim 3
Dependent Claim
36 words
Method according to any of claims 1 or 2, wherein the sum of
all weighting functions, evaluated in any original colour x ,
is not greater than one : Σ K W K ( x )≤1.
Claim 4
Dependent Claim
26 words
Method according to any of claims 1 to 3, wherein each
weighting function W K ( x ) is defined by an extent and a shape.
Claim 5
Dependent Claim
37 words
Method according to claim 4, wherein said extent is defined by
at least one action radius or by one or two action radii per
coordinate axis, each action radius having said selected
colour µ K as origin.
Claim 6
Dependent Claim
22 words
Method according to claim 5, wherein said action radius is
defined in a colour space having HSL, HSV or Lch coordinate
axes.
Claim 7
Dependent Claim
23 words
Method according to any of claims 4 to 6, wherein the extent
is set to comprise all colours contributing to said selected
colour.
Claim 8
Dependent Claim
27 words
Method according to any of claims 4 to 7, wherein the shape of
the weighting function W K ( x ) is different for different
coordinate axes.
Claim 9
Dependent Claim
24 words
Method according to any of claims 4 to 8, wherein said shape
is based on the distribution of colours contributing to said
selected colour.
Claim 10
Dependent Claim
59 words
Method according to any of claims 1 to 9, wherein a. said original colour x , b. said selected colour µ K , c. said required colour change δ K , and/or d. said colour modification is defined in an RGB, Lab, CMY, CMYK, HiFi or named colour
space, preferentially the same space for a, b, c and d.
Claim 11
Dependent Claim
28 words
Method according to any of claims 1 to 10, wherein said colour
modification is combined with a global colour transformation,
suitable for application to said original colour image.
Claim 12
Dependent Claim
18 words
Method according to claim 11, wherein said global colour
transformation is defined on a sparse grid of colours.
Claim 13
Dependent Claim
19 words
Method according to any of claims 1 to 12, wherein said
selected colour is obtained from said colour image.
Claim 14
Dependent Claim
38 words
Method according to any of claims 1 to 13, wherein said colour
change δ K is obtained from the difference between : a desired colour selected on a reference colour image and said selected colour µ K .
Claim 15
Dependent Claim
63 words
Method according to any of claims 1 to 14, wherein said
weighting function W K ( x ) is not increasing as a distance D K between said original colour x and said selected colour µ K increases, as long as D K is smaller than a same distance
between said selected colour µ K and any different selected
colour µ J .
Claim 16
Dependent Claim
57 words
Method according to any of claims 1 to 15, wherein said
weighting function W K ( x ) decreases according to a linear,
quadratic, cubic, gaussian or another function selected by an
operator or is proportional to the inverse of a distance D K between said original colour x and the corresponding selected
colour µ K .
References Cited (Backward Citations)
No citation records indexed.
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