US 8,300,051 B2 · Apparatus and method for enhancing images in consideration of region characteristics

Abstract

Disclosed herein is an apparatus for enhancing images in consideration of region characteristics. An inverse gamma correction unit releases gamma correction and linearizes each of Red (R), Green (G), and Blue (B) colors. A threshold calculation unit calculates m-1 thresholds in order to divide the brightness of pixels into m regions, and labels each of the pixels as one of the m brightness regions. A block segmentation unit divides an input image into M×N blocks. A block statistics calculation unit determines one of the m brightness regions to which each of the blocks pertains, and labels the block as the corresponding brightness region. A block-based Look-Up Table (LUT) generation unit generates enhancement LUTs for the respective blocks. An image enhancement unit corrects the image using the LUTs for the respective blocks. A gamma correction unit performs gamma correction.

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Claims15

Dependent claims

An apparatus for enhancing images in consideration of region characteristics, comprising:

an inverse gamma correction unit for releasing gamma correction and linearizing each of Red (R), Green (G), and Blue (B) colors;
a threshold calculation unit for calculating m-1 thresholds in order to divide brightness of pixels into m regions, and labeling each of the pixels as one of the m brightness regions;
a block segmentation unit for dividing an input image into M×N blocks;
a block statistics calculation unit for determining one of the m brightness regions to which each of the blocks pertains, and labeling the blocks as a corresponding brightness region;
a block-based Look-Up Table (LUT) generation unit for generating enhancement LUTs for the respective blocks;
an image enhancement unit for enhancing the image using the LUTs for the respective blocks, which are generated through the block-based LUT generation unit;
and
a gamma correction unit for performing gamma correction and wherein the block-based LUT generation unit generates LUTs for the respective blocks by combining m LUTs, primary LUTs for the respective blocks being generated by combining the LUTs of the respective blocks using overlapping of brightness regions and block indexes for m basis LUTs, and final LUTs for the respective blocks being generated using averages or weighted averages between the primary LUTs for respective blocks and LUTs for adjacent blocks.

5 more elements

A method of enhancing images in consideration of region characteristics, comprising the steps of:

(a) an inverse gamma correction unit releasing gamma correction applied for display of an image, and linearizing each of R, G, and B colors;
(b) a threshold calculation unit calculating m-1 thresholds in order to divide brightness of pixels into m regions, and labeling each of the pixels as one of the m brightness regions;
(c) a block segmentation unit dividing an input image into M×N blocks;
(d) a block statistics calculation unit calculating block indexes capable of indicating statistical characteristics of the blocks, determining one of the m brightness regions to which each of the blocks pertains, and labeling the blocks as a corresponding brightness region;
(e) a block-based Look-Up Table (LUT) generation unit generating primary LUTs for the respective blocks by combining LUTs for the respective blocks using overlapping of brightness regions and block indexes for m basis LUTs, and then generating final LUTs for the respective blocks by obtaining averages or weighted averages between the primary LUTs for the respective blocks and LUTs for adjacent blocks;
(f) an image enhancement unit enhancing values of the pixels of the blocks using the LUTs for the respective blocks generated through the step (e);
and
(g) a gamma correction unit applying again gamma correction that has been released through the inverse gamma correction unit.

5 more elements

Dependencies are inferred from the claim text.

Description5,345 words

Summary1,343 words

#1. Field of the Invention

#The present invention relates generally to an apparatus and method for enhancing images, and, more particularly, to an apparatus and method for enhancing images, having the limited dynamic range of a brightness level, such as images taken in a backlight compensation mode, to high dynamic range images.

#2. Description of the Related Art

Brief description of the drawings10 figures

#The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

#FIG. 1 is a diagram showing the overall configuration of an apparatus for enhancing images according to the present invention;

#FIG. 2 is a view showing an example of inverse gamma correction according to the present invention;

Detailed description3,729 words

#Reference now should be made to the drawings, in which the same reference numerals are used throughout the different drawings to designate the same or similar components.

#Features and advantages of the present invention will be described in detail with reference to the attached drawings below. It should be noted that, in the following description, when it is determined that a detailed description of well-known functions related to the present invention and the construction thereof would make the gist of the present invention obscure, they will be omitted.

#The present invention will be described in detail with reference to the attached drawings below.

Facts

Application

12/274,495Filed 20 Nov 2008

Priority

KR 10-2008-00987238 Oct 2008

Published

US 2010/0085361 A18 Apr 2010

Granted

30 Oct 2012

Term ends

14 Aug 2031

Estimated · how

20 years from earliest known nonprovisional domestic filing plus recorded patent term adjustment, including 997 days of adjustment. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification11 codes

G06T 5/94
Dynamic range modification of images or parts thereof: based on local image properties, e.g. for local contrast enhancement
G06T 5/40
Image enhancement or restoration: using histogram techniques
G09G 3/20
Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes: for presentation of an…
G06T 2207/20021
Special algorithmic details: dividing image into blocks, subimages or windows

Timeline

8 Oct 2008Priority claimedKR 10-2008-0098723
20 Nov 2008Application filedUS 12/274,495
20 Nov 2008Assigned to Korea Advanced Institute of Science and Technologyassignment of assignor's interest
8 Apr 2010PublishedUS 2010/0085361 A1
30 Oct 2012GrantedUS 8,300,051 B2
12 Oct 2026TodayWithin its term
14 Aug 2031Term endsEstimated, includes 997 days of adjustment

Apparatus and method for enhancing images in consideration of region characteristics

Life of this patent

Apparatus and method for enhancing images in consideration of region characteristics

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims15

Description5,345 words

Drawings

Classification11 codes

Life of this patent

Description5,345 words