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EP0911759A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

apparatus and a method for reducing red-eye in an image

Assignee: HP Inc
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Filing: 1998-10-16
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Granted: —
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Expires: 2018-10-16
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Abstract

Abstract A red-eye reduction system (10) includes a masking module (16) which converts an image (11) into a mask having first state areas representing red colour pixels of the image and second state areas representing other colour pixels of the image. The image (11) includes an eye with a red pupil. A pupil locating module (17) is coupled to the masking module (16) to locate a substantially first state area in the mask that resembles a pupil. A colour replacing module (18) is then coupled to the pupil locating module (17) to change the red colour pixels in the area into monochrome (grey) or other predefined colours. The colour replacing module (18) also adjusts the boundary of the area by changing the colours of pixels in close proximity to the area if the colour of these pixels is determined to be sufficiently close to red such that natural appearance of the eye is maintained when reducing the red pupil.

Inventors

  • 👤 Qian Lin
  • 👤 Konstantinos Konstantinides
  • 👤 Daniel R. Tretter
  • 👤 Andrew Parry

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-09 10:17
CPC Classifications
G; G06; G06V; G06V40/00; G06V40/10; G06V40/18; G06V40/193; G06T; G06T7/00; G06T7/90; G06T2207/00; G06T2207/30; G06T2207/30216

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 145 words
A red-eye reduction system, comprising: (A) a masking module (16) operable to convert an image (11) into a mask having first state areas representing red colour pixels and second state areas representing other colour pixels, wherein the image (11) includes an eye with a red pupil; (B) a pupil locating module (17) coupled to the masking module (16) operable to locate a substantially first state area in the mask that resembles a pupil; (C) a colour replacing module (18) coupled to the pupil locating module (17) operable to change the red colour pixels in the area into a predetermined colours wherein the colour replacing module (18) is also operable to adjust boundary of the area by changing the colours of pixels in close proximity to the area to the predetermined colour if the colour of these pixels is determined to be sufficiently close to red.
Claim 2
Dependent Claim 93 words
A red-eye reduction system as in claim 1, wherein the pupil locating module (17) is operable to detect if the substantially first state area resembles a pupil by determining if the substantially first state area is a substantially largest first state area within the mask, wherein after determining that the substantially first state area resembles a pupil, the pupil locating module (17) is operable to modify the mask by changing all other first state areas in the mask into second state such that the modified mask only has the substantially first state area.
Claim 3
Dependent Claim 69 words
A red-eye reduction system as in claim 1, wherein the substantially first state area includes a second state area within the first state area. wherein the second state area represents the glint in the pupil, wherein the predetermined colour is a zero chrominance, wherein the colour replacing module (18) is operable to change the luminance value of all pixels within the substantially first state area by a predetermined factor.
Claim 4
Dependent Claim 47 words
A red-eye reduction system as in any one of claims 1 to 3. wherein the masking module (16) is operable to convert the image into the mask by first raising red-green-blue values of the image to a predetermined power and then to perform a standard luminance-chrominance conversion.
Claim 5
Dependent Claim 68 words
A red-eye reduction system as in any one of claims 1 to 4, wherein the colour replacing module (18) is operable to determine if the colour of the adjacent pixel is sufficiently close to red by comparing the colour value of the adjacent pixel with (i) a median red value and (ii) a median green value of all the red colour pixels within the substantially first state area.
Claim 6
Dependent Claim 33 words
A red-eye reduction system as in any one of claims 1 to 5, wherein the adjacent pixel is a pixel that has at least one neighbouring pixel in the substantially first state area.
Claim 7
Independent Claim 116 words
A method of reducing red-eye effect in a digital image (11), comprising: (A) converting an image (11) having an eye with a red pupil into a mask having first state areas representing red colour pixels of the image and second state areas representing other colour pixels of the image; (B) processing the mask to locate a substantially first state area in the mask that resembles a pupil; (C) changing the red colour pixels in the area into a predetermined colour with boundary adjustments such that the colour of pixels in close proximity to the area is also changed to the predetermined colour if the colour of these pixels is determined to be sufficiently close to red.
Claim 8
Dependent Claim 72 words
A method as in claim 7. wherein the step (B) comprises the steps of: (I) determining if the substantially first state area is a largest substantially first state area in the mask; (II) determining if the substantially first state area is substantially circular; (III) modifying the mask by changing all other first state areas in the mask into second state such that the modified mask only has the substantially first state area.
Claim 9
Dependent Claim 64 words
A method as in claim 7 or 8, wherein the step (C) comprises the steps of: (a) changing the colour of the red colour pixels within the substantially first state area to the predetermined colour by setting the chrominance of the red colour pixels to zero; (b) changing the luminance value of all pixels within the substantially first state area by a predetermined factor.
Claim 10
Dependent Claim 35 words
A method as in claim 9, wherein the step (A) comprises the steps of: (a) raising red-green-blue values of the image to a predetermined power: (b) performing a standard luminance-chrominance conversion; (c) creating the mask.

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