SlideShare a Scribd company logo
BI-HISTOGRAM EQUALIZATION
wITH A pLATEAU LIMIT
FOR DIGITAL IMAGES.
MAHESH MOHAN.M.R
GECT S1 ECE
ROLL NO: 7
GUIDE : Dr.V.S.SHEEBA
OM NAMA
SIVAYA
OBJECTIVE
.
TO FAMILARIZE WITH
.HISTOGRAM EQUALIZATION
.DIFFERENT EQUALIZATION METHODS
.THEIR DRAWBACK AND HOW IT IS RECTIFIED.
FLOw OF SEMINAR.
1.WHAT IS A DIGITAL IMAGE?
2.WHAT IS A HISTOGRAM?
3.WHAT IS HISTOGRAM EQUALIZATION?
4.DIFFERENT EQUALIZATION METHODS AND ITS DRAWBACK.
5.HOW DRAWBACK OF EACH METHOD IS RECTIFED?
• A digital image is a matrix representation of a 
two-dimensional image. 
                        
                         
                           
wHAT IS A DIGITAL IMAGE?
Colour imageGray scale image(Black and white)
dGray Image
Image
wHAT IS A GRAy SCALE IMAGE?
243 121
.
34 21
.
. .
Gray level matrix
0 255
Image matrix
Image
wHAT IS A COLOUR IMAGE?
234 212 123
135 231 233
.
121 222
. .
243 121
.
. . .
112 167
.
. . .
Red matrix
Green matrix
Blue matrix
.
.
wHAT IS A HISTOGRAM?
Consider a 5x5 image with integer intensities in the range between zero and seven:
0 7 3 2 3
0 0 0 6 7
7 7 2 2 0
1 1 0 4 1
0 0 7 4 1
Image matrixImage
0 1 2 3 4 5 6 7
Gray scale
Black White
wHAT IS A HISTOGRAM?
Consider a 5x5 image with integer intensities in the range between one and eight:
0 7 3 2 3
0 0 0 6 7
7 7 2 2 0
1 1 0 4 1
0 0 7 4 1
Image matrixImage
0 1 2 3 4 5 6 7
Grey scale
Black White
Number of pixel with intensity value 0 [h(r0)] = 8
wHAT IS A HISTOGRAM?
0 7 3 2 3
0 0 0 6 7
7 7 2 2 0
1 1 0 4 1
0 0 7 4 1
Image matrixImage
0 1 2 3 4 5 6 7
Grey scale
Black White
Number of pixel with intensity value 0 [h(r0)] = 8
Similarly for 1 h(r1) = 4
wHAT IS A HISTOGRAM?
0 7 3 2 3
0 0 0 6 7
7 7 2 2 0
1 1 0 4 1
0 0 7 4 1
Image matrixImage
Similarly
INTENSITY r 0 1 2 3 4 5 6 7
NUMBER of
pixels of r
h(r)
  h(r0)=8   h(r1)=4 h(r2)=3  h(r3)=2  h(r4)=2  h(r5)=0  h(r6)=1   h(r7)=5
r
wHAT IS A HISTOGRAM?
Image matrix
0 1 2 3 4 5 6 7
HISTOGRAM
Intensity values
Number of pixels of
intensity r
r 0 1 2 3 4 5 6 7
h(r)   8     4    3     2     2     0     1     5
Histogram plots the number of pixels for each intensity value.
h(r)
What is a histogram?
r 0 1 2 3 4 5 6 7
h(r) 8 4 3 2 2 0 1 5
p(r)
h(r)/(5*5)
8/25 4/25 3/25 2/25 2/25 0/25 1/25 5/25
HISTOGRAM - h(r) - Y axis - number of intensities
NORMALIZED HISTOGRAM - p(r) - Y axis - probability of intensities
SAMPLE IMAGES AND ITS HISTOGRAM
Bright image
Intensity range 0 - 255
SAMPLE IMAGES AND ITS HISTOGRAM
Bright image
Intensity range 0 - 255
0 50 100 150 200 255
Intensity
No:ofpixels
DARK BRIGHT
h(r)
SAMPLE IMAGES AND ITS HISTOGRAM
Dark image
Intensity range 0 - 255
SAMPLE IMAGES AND ITS HISTOGRAM
Dark image
Intensity range 0 - 255
0 50 100 150 200 255
Intensity
No:ofpixels
h(r)
SAMPLE IMAGES AND ITS HISTOGRAM
Low contrast image
Intensity range 0 - 255
SAMPLE IMAGES AND ITS HISTOGRAM
Light image
Intensity range 0 - 255
0 50 100 150 200 255
Intensity
No:ofpixels
h(r)
SAMPLE IMAGES AND ITS HISTOGRAM
Bright image
Dark image
Low contrast
image
SAMPLE IMAGES AND ITS HISTOGRAM
High contrast image
Intensity range 0 - 255
0 50 100 150 200 255
Intensity
No:ofpixels
h(r)
CoNCEPt oF histogram EQUaLiZatioN
ORIGINAL IMAGE EQUALIZED IMAGE
MAXIMIZES ENTROPY OF AN IMAGE.
s1 s2
thEorY BEhiND histogram
EQUaLiZatioN
TRANSFORMATION FUNCTION THAT MAPS THE
INPUT INTENSITY TO ALL AVAILABLE INTENSITIES.
I/p intensity
O/p intensity
THEORY BEHIND HISTOGRAM
EQUALIZATION
ORIGINAL IMAGE EQUALIZED IMAGE
s1 s2
THEORY BEHIND HISTOGRAM
EQUALIZATION
CUMULATIVE DISTRIBUTION
FUNCTION T(r)
0 50 100 150 200 255
[76 – 213]
[0 – 48]
[15 – 100] [25 – 125]
O/P INTENSITY = X0 + [( Xl-1 –X0 )*C(x)]
I/P intensity
DIFFERENT STAGES
GLOBAL HISTOGRAM
EQUALIZATION
BI-HISTOGRAM
EQUALIZATION
BI-HISTOGRAM
EQUALIZATION
WITH A PLATEAU LIMIT
GLOBAL HISTOGRAM EQUALIZATION
OBTAIN
HISTOGRAM
OBTAIN PDF
OBTAIN CDF
OBTAIN
TRANSFORMATIO
N FUNCTION
MAPPING OF NEW
INTENSITY VALUES
NEW HISTOGRAM
Original histogram
M*N
PDF
1..
CDF
1
x0
XL-1
O/P
x0
XL-1
MappingTransformation
function
t1
t2
t2
New histogram
t1t1 t2
t2t1t2t1
GLOBAL HISTOGRAM EQUALIZATION
RESULTS
GHE
O/P MEAN CONSTANTWHY ?
GLOBAL HISTOGRAM EQUALIZATION
DRAWBACK
DO NOT CONSERVE THE MEAN.
WHY MEAN IMPORTANT?
Video frames
GHE
THEORY OF BIHISTOGRAM EQUALIZATION
HISTOGRAM EQUALIZED SEPERATELY AROUND MEAN.
THUS CONSERVE THE MEAN.
ORIGINAL HISTOGRAM BIHISTOGRAM EQUALIZED
BIHISTOGRAM EQUALIZATION
OBTAIN PDF
(lower subimage)[X0-Xm]
OBTAIN CDF
OBTAIN
TRANSFORMATIO
N FUNCTION
MAPPING OF NEW
INTENSITY VALUES
NEW HISTOGRAM
DIVIDE HISTOGRAM WITH RESPECT TO
INTENSITY MEAN (X m ).
OBTAIN
HISTOGRAM
OBTAIN PDF
(upper subimage)[Xm-Xl-1]
OBTAIN CDF
OBTAIN
TRANSFORMATIO
N FUNCTION
MAPPING OF NEW
INTENSITY VALUES
+
GHE
GHE
Partition
Merging
BI-HISTOGRAM EQUALIZATION RESULTS
BHE
BIHISTOGRAM EQUALIZATION DRAWBACK
LEVEL SATURATION DUE TO HIGH PROBABLE
INTENSITY VALUES.
BHE
EXAMPLE
WHY IT HAPPENS ?
THOERY OF BIHISTOGRAM EQUALIZATION
WITH A PLATEAU LIMIT .
BIHISTOGRAM CLIPPING HISTOGRAM
ABOVE PLATEAU LIMIT
TL PLATEAU LIMITS FOR LOWER HISTOGRAM.
TU PLATEAU LIMITS FOR UPPER HISTOGRAM.
SELECT PLATEAU LIMIT
BIHISTOGRAM EQUALIZATION WITH A
PLATEAU LIMIT
OBTAIN PDF
(lower subimage)[X0-Xm]
OBTAIN CDF
OBTAIN
TRANSFORMATION
FUNCTION
MAPPING OF NEW
INTENSITY VALUES
NEW HISTOGRAM
DIVIDE HISTOGRAM WITH RESPECT TO
INTENSITY MEAN (X m ).
OBTAIN
HISTOGRAM
OBTAIN PDF
(upper subimage)[Xm-Xl-1]
OBTAIN CDF
OBTAIN
TRANSFORMATION
FUNCTION
MAPPING OF NEW
INTENSITY VALUES
+
GHE
GHE
Partition
Merging
CLIP WRT
AMPLITUDE MEAN
CLIP WRT
AMPLITUDE MEAN
Clipping
BIHISTOGRAM EQUALIZATION WITH A
PLATEAU LIMIT RESULTS
BHEPL
SIMULATION RESULTS
TEST IMAGES GLOBAL
HISTOGRAM
EQUALIZATION
BI-HISTOGRAM
EQUALIZATION
BIHISTOGRAM
EQUALIZATION WITH
PLATEAU LIMIT
DARK 86 126 82 91
BRIGHT 143 126 154 153
LOWCONTRAST 77 124 99 103
MEAN VALUES
SIMULATION RESULTS
LEVEL SATURATION
TEST IMAGES BI-HISTOGRAM
EQUALIZATION
BIHISTOGRAM
EQUALIZATION WITH
PLATEAU LIMIT
WHITE DOT YES NO
d
WHY GRAY SCALE IMAGES INSTEAD
OF COLOUR IMAGES?
.
CONCLUSIONHistogram?
IN AN IMAGE
NOTHING WORSE MORE THAN LOW CONTRAST
GLOBAL HISTOGRAM EQUALIZATION
NOTHING WORSE MORE THAN MEAN CONSERVATION
BI-HISTOGRAM EQUALIZATION
NOTHING WORSE MORE
THAN ………………?
NOTHING WORSE MORE THAN LEVEL SATURATION
BI-HISTOGRAM EQUALIZATION WITH PLATEAU LIMIT
REFERENCESStogram?
Bi-Histogram Equalization with a Plateau Limit
for Digital Image Enhancement
Chen Hee Ooi, Student Member, IEEE, Nicholas Sia Pik Kong,
Student Member, IEEEand Haidi Ibrahim, Member, IEEE
IEEE Transactions on Consumer Electronics, Vol. 55, No. 4,
NOVEMBER 2009
Contrast Enhancement Using Brightness Preserving
Bi-Histogram Equalization
YEONG-TAEG KIM, MEMBER, IEEE
Color Image Enhancement Using Brightness Preserving
Dynamic Histogram Equalization
Nicholas Sia Pik Kong, Student Member, IEEE, and Haidi
Ibrahim, Member, IEEE.
Preserving brightness in histogram equalization
based contrast enhancement techniques
Soong-Der Chen a, Abd. Rahman Ramli
Digital image processing by Gonzalez and Woods
NAMASIVAYA
• Lorem ipsum dolor sit amet, consectetuer
adipiscing elit. Vivamus et magna. Fusce sed
sem sed magna suscipit egestas.
• Lorem ipsum dolor sit amet, consectetuer
adipiscing elit. Vivamus et magna. Fusce sed
sem sed magna suscipit egestas.
1
• Lorem ipsum dolor sit amet, consectetuer
adipiscing elit. Vivamus et magna. Fusce sed
sem sed magna suscipit egestas.
• Lorem ipsum dolor sit amet, consectetuer
adipiscing elit. Vivamus et magna. Fusce sed
sem sed magna suscipit egestas.
1

More Related Content

What's hot

Image segmentation
Image segmentation Image segmentation
Homomorphic filtering
Homomorphic filteringHomomorphic filtering
Homomorphic filtering
Gautam Saxena
 
SPATIAL FILTERING IN IMAGE PROCESSING
SPATIAL FILTERING IN IMAGE PROCESSINGSPATIAL FILTERING IN IMAGE PROCESSING
SPATIAL FILTERING IN IMAGE PROCESSING
muthu181188
 
Region based segmentation
Region based segmentationRegion based segmentation
Region based segmentation
ramya marichamy
 
Digital Image Processing
Digital Image ProcessingDigital Image Processing
Digital Image Processing
lalithambiga kamaraj
 
Digital Image Processing: Image Segmentation
Digital Image Processing: Image SegmentationDigital Image Processing: Image Segmentation
Digital Image Processing: Image Segmentation
Mostafa G. M. Mostafa
 
Region Splitting and Merging Technique For Image segmentation.
Region Splitting and Merging Technique For Image segmentation.Region Splitting and Merging Technique For Image segmentation.
Region Splitting and Merging Technique For Image segmentation.
SomitSamanto1
 
Image feature extraction
Image feature extractionImage feature extraction
Image feature extractionRushin Shah
 
NOISE FILTERS IN IMAGE PROCESSING
NOISE FILTERS IN IMAGE PROCESSINGNOISE FILTERS IN IMAGE PROCESSING
NOISE FILTERS IN IMAGE PROCESSING
Animesh Singh Sengar
 
Edge Detection and Segmentation
Edge Detection and SegmentationEdge Detection and Segmentation
Edge Detection and Segmentation
A B Shinde
 
Chapter 9 morphological image processing
Chapter 9   morphological image processingChapter 9   morphological image processing
Chapter 9 morphological image processing
Ahmed Daoud
 
Image Enhancement using Frequency Domain Filters
Image Enhancement using Frequency Domain FiltersImage Enhancement using Frequency Domain Filters
Image Enhancement using Frequency Domain Filters
Karthika Ramachandran
 
Histogram Processing
Histogram ProcessingHistogram Processing
Histogram Processing
Amnaakhaan
 
Sharpening spatial filters
Sharpening spatial filtersSharpening spatial filters
Image Restoration (Digital Image Processing)
Image Restoration (Digital Image Processing)Image Restoration (Digital Image Processing)
Image Restoration (Digital Image Processing)
Kalyan Acharjya
 
Image Representation & Descriptors
Image Representation & DescriptorsImage Representation & Descriptors
Image Representation & Descriptors
PundrikPatel
 
digital image processing
digital image processingdigital image processing
digital image processing
Abinaya B
 
Color Image Processing
Color Image ProcessingColor Image Processing
Color Image Processing
kiruthiammu
 
Chapter 1 and 2 gonzalez and woods
Chapter 1 and 2 gonzalez and woodsChapter 1 and 2 gonzalez and woods
Chapter 1 and 2 gonzalez and woods
asodariyabhavesh
 

What's hot (20)

Image segmentation
Image segmentation Image segmentation
Image segmentation
 
Homomorphic filtering
Homomorphic filteringHomomorphic filtering
Homomorphic filtering
 
SPATIAL FILTERING IN IMAGE PROCESSING
SPATIAL FILTERING IN IMAGE PROCESSINGSPATIAL FILTERING IN IMAGE PROCESSING
SPATIAL FILTERING IN IMAGE PROCESSING
 
Region based segmentation
Region based segmentationRegion based segmentation
Region based segmentation
 
Digital Image Processing
Digital Image ProcessingDigital Image Processing
Digital Image Processing
 
Digital Image Processing: Image Segmentation
Digital Image Processing: Image SegmentationDigital Image Processing: Image Segmentation
Digital Image Processing: Image Segmentation
 
Region Splitting and Merging Technique For Image segmentation.
Region Splitting and Merging Technique For Image segmentation.Region Splitting and Merging Technique For Image segmentation.
Region Splitting and Merging Technique For Image segmentation.
 
Image feature extraction
Image feature extractionImage feature extraction
Image feature extraction
 
NOISE FILTERS IN IMAGE PROCESSING
NOISE FILTERS IN IMAGE PROCESSINGNOISE FILTERS IN IMAGE PROCESSING
NOISE FILTERS IN IMAGE PROCESSING
 
Edge Detection and Segmentation
Edge Detection and SegmentationEdge Detection and Segmentation
Edge Detection and Segmentation
 
Chapter 9 morphological image processing
Chapter 9   morphological image processingChapter 9   morphological image processing
Chapter 9 morphological image processing
 
Image Enhancement using Frequency Domain Filters
Image Enhancement using Frequency Domain FiltersImage Enhancement using Frequency Domain Filters
Image Enhancement using Frequency Domain Filters
 
Histogram Processing
Histogram ProcessingHistogram Processing
Histogram Processing
 
Sharpening spatial filters
Sharpening spatial filtersSharpening spatial filters
Sharpening spatial filters
 
Image Restoration (Digital Image Processing)
Image Restoration (Digital Image Processing)Image Restoration (Digital Image Processing)
Image Restoration (Digital Image Processing)
 
Image Representation & Descriptors
Image Representation & DescriptorsImage Representation & Descriptors
Image Representation & Descriptors
 
Spatial filtering
Spatial filteringSpatial filtering
Spatial filtering
 
digital image processing
digital image processingdigital image processing
digital image processing
 
Color Image Processing
Color Image ProcessingColor Image Processing
Color Image Processing
 
Chapter 1 and 2 gonzalez and woods
Chapter 1 and 2 gonzalez and woodsChapter 1 and 2 gonzalez and woods
Chapter 1 and 2 gonzalez and woods
 

Similar to Histogram equalization

Histogram based enhancement
Histogram based enhancementHistogram based enhancement
Histogram based enhancement
liba manopriya.J
 
Histogram based Enhancement
Histogram based Enhancement Histogram based Enhancement
Histogram based Enhancement
Vivek V
 
Lec-04 Image Enhancement II.ppt
Lec-04 Image Enhancement II.pptLec-04 Image Enhancement II.ppt
Lec-04 Image Enhancement II.ppt
MUHAMMADATTAURREHMAN7
 
Dip3
Dip3Dip3
Introduction to Image Processing
Introduction to Image ProcessingIntroduction to Image Processing
Introduction to Image Processing
Israel Gbati
 
chapter-2.1 Histogram.ppt
chapter-2.1 Histogram.pptchapter-2.1 Histogram.ppt
chapter-2.1 Histogram.ppt
AyeleFeyissa1
 
ModuleII.ppt
ModuleII.pptModuleII.ppt
ModuleII.ppt
SKILL2021
 
ModuleII.ppt
ModuleII.pptModuleII.ppt
ModuleII.ppt
AkashVerma916093
 
ModuleII.ppt
ModuleII.pptModuleII.ppt
ModuleII.ppt
nishashreyan1
 
Lec_2_Digital Image Fundamentals.pdf
Lec_2_Digital Image Fundamentals.pdfLec_2_Digital Image Fundamentals.pdf
Lec_2_Digital Image Fundamentals.pdf
nagwaAboElenein
 
Intensity transformation & histogram processing
Intensity transformation & histogram processingIntensity transformation & histogram processing
Intensity transformation & histogram processing
Dëèp Çhõkshï
 
_Histogram.ppt............................
_Histogram.ppt............................_Histogram.ppt............................
_Histogram.ppt............................
MuhammadKhalil858111
 
Image enhancement in the spatial domain1
Image enhancement in the spatial domain1Image enhancement in the spatial domain1
Image enhancement in the spatial domain1
shabanam tamboli
 
Image Enhancement in the Spatial Domain1.ppt
Image Enhancement in the Spatial Domain1.pptImage Enhancement in the Spatial Domain1.ppt
Image Enhancement in the Spatial Domain1.ppt
ShabanamTamboli1
 
Comparison of image segmentation
Comparison of image segmentationComparison of image segmentation
Comparison of image segmentation
Haitham Ahmed
 
G Intensity transformation and spatial filtering(1).ppt
G Intensity transformation and spatial filtering(1).pptG Intensity transformation and spatial filtering(1).ppt
G Intensity transformation and spatial filtering(1).ppt
deekshithadasari26
 
COM2304: Intensity Transformation and Spatial Filtering – I (Intensity Transf...
COM2304: Intensity Transformation and Spatial Filtering – I (Intensity Transf...COM2304: Intensity Transformation and Spatial Filtering – I (Intensity Transf...
COM2304: Intensity Transformation and Spatial Filtering – I (Intensity Transf...
Hemantha Kulathilake
 
Comparison of Histogram Equalization Techniques for Image Enhancement of Gray...
Comparison of Histogram Equalization Techniques for Image Enhancement of Gray...Comparison of Histogram Equalization Techniques for Image Enhancement of Gray...
Comparison of Histogram Equalization Techniques for Image Enhancement of Gray...
IJMER
 

Similar to Histogram equalization (20)

Histogram based enhancement
Histogram based enhancementHistogram based enhancement
Histogram based enhancement
 
Histogram based Enhancement
Histogram based Enhancement Histogram based Enhancement
Histogram based Enhancement
 
Histogram processing
Histogram processingHistogram processing
Histogram processing
 
Lec-04 Image Enhancement II.ppt
Lec-04 Image Enhancement II.pptLec-04 Image Enhancement II.ppt
Lec-04 Image Enhancement II.ppt
 
Dip3
Dip3Dip3
Dip3
 
Introduction to Image Processing
Introduction to Image ProcessingIntroduction to Image Processing
Introduction to Image Processing
 
chapter-2.1 Histogram.ppt
chapter-2.1 Histogram.pptchapter-2.1 Histogram.ppt
chapter-2.1 Histogram.ppt
 
ModuleII.ppt
ModuleII.pptModuleII.ppt
ModuleII.ppt
 
ModuleII.ppt
ModuleII.pptModuleII.ppt
ModuleII.ppt
 
ModuleII.ppt
ModuleII.pptModuleII.ppt
ModuleII.ppt
 
Lec_2_Digital Image Fundamentals.pdf
Lec_2_Digital Image Fundamentals.pdfLec_2_Digital Image Fundamentals.pdf
Lec_2_Digital Image Fundamentals.pdf
 
Intensity transformation & histogram processing
Intensity transformation & histogram processingIntensity transformation & histogram processing
Intensity transformation & histogram processing
 
_Histogram.ppt............................
_Histogram.ppt............................_Histogram.ppt............................
_Histogram.ppt............................
 
Image enhancement in the spatial domain1
Image enhancement in the spatial domain1Image enhancement in the spatial domain1
Image enhancement in the spatial domain1
 
Image Enhancement in the Spatial Domain1.ppt
Image Enhancement in the Spatial Domain1.pptImage Enhancement in the Spatial Domain1.ppt
Image Enhancement in the Spatial Domain1.ppt
 
Comparison of image segmentation
Comparison of image segmentationComparison of image segmentation
Comparison of image segmentation
 
G Intensity transformation and spatial filtering(1).ppt
G Intensity transformation and spatial filtering(1).pptG Intensity transformation and spatial filtering(1).ppt
G Intensity transformation and spatial filtering(1).ppt
 
COM2304: Intensity Transformation and Spatial Filtering – I (Intensity Transf...
COM2304: Intensity Transformation and Spatial Filtering – I (Intensity Transf...COM2304: Intensity Transformation and Spatial Filtering – I (Intensity Transf...
COM2304: Intensity Transformation and Spatial Filtering – I (Intensity Transf...
 
Comparison of Histogram Equalization Techniques for Image Enhancement of Gray...
Comparison of Histogram Equalization Techniques for Image Enhancement of Gray...Comparison of Histogram Equalization Techniques for Image Enhancement of Gray...
Comparison of Histogram Equalization Techniques for Image Enhancement of Gray...
 
rs and gis
rs and gisrs and gis
rs and gis
 

Recently uploaded

Water Industry Process Automation and Control Monthly - May 2024.pdf
Water Industry Process Automation and Control Monthly - May 2024.pdfWater Industry Process Automation and Control Monthly - May 2024.pdf
Water Industry Process Automation and Control Monthly - May 2024.pdf
Water Industry Process Automation & Control
 
HYDROPOWER - Hydroelectric power generation
HYDROPOWER - Hydroelectric power generationHYDROPOWER - Hydroelectric power generation
HYDROPOWER - Hydroelectric power generation
Robbie Edward Sayers
 
Governing Equations for Fundamental Aerodynamics_Anderson2010.pdf
Governing Equations for Fundamental Aerodynamics_Anderson2010.pdfGoverning Equations for Fundamental Aerodynamics_Anderson2010.pdf
Governing Equations for Fundamental Aerodynamics_Anderson2010.pdf
WENKENLI1
 
power quality voltage fluctuation UNIT - I.pptx
power quality voltage fluctuation UNIT - I.pptxpower quality voltage fluctuation UNIT - I.pptx
power quality voltage fluctuation UNIT - I.pptx
ViniHema
 
The Benefits and Techniques of Trenchless Pipe Repair.pdf
The Benefits and Techniques of Trenchless Pipe Repair.pdfThe Benefits and Techniques of Trenchless Pipe Repair.pdf
The Benefits and Techniques of Trenchless Pipe Repair.pdf
Pipe Restoration Solutions
 
ethical hacking in wireless-hacking1.ppt
ethical hacking in wireless-hacking1.pptethical hacking in wireless-hacking1.ppt
ethical hacking in wireless-hacking1.ppt
Jayaprasanna4
 
English lab ppt no titlespecENG PPTt.pdf
English lab ppt no titlespecENG PPTt.pdfEnglish lab ppt no titlespecENG PPTt.pdf
English lab ppt no titlespecENG PPTt.pdf
BrazilAccount1
 
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)
MdTanvirMahtab2
 
road safety engineering r s e unit 3.pdf
road safety engineering  r s e unit 3.pdfroad safety engineering  r s e unit 3.pdf
road safety engineering r s e unit 3.pdf
VENKATESHvenky89705
 
Architectural Portfolio Sean Lockwood
Architectural Portfolio Sean LockwoodArchitectural Portfolio Sean Lockwood
Architectural Portfolio Sean Lockwood
seandesed
 
Planning Of Procurement o different goods and services
Planning Of Procurement o different goods and servicesPlanning Of Procurement o different goods and services
Planning Of Procurement o different goods and services
JoytuBarua2
 
Fundamentals of Electric Drives and its applications.pptx
Fundamentals of Electric Drives and its applications.pptxFundamentals of Electric Drives and its applications.pptx
Fundamentals of Electric Drives and its applications.pptx
manasideore6
 
一比一原版(IIT毕业证)伊利诺伊理工大学毕业证成绩单专业办理
一比一原版(IIT毕业证)伊利诺伊理工大学毕业证成绩单专业办理一比一原版(IIT毕业证)伊利诺伊理工大学毕业证成绩单专业办理
一比一原版(IIT毕业证)伊利诺伊理工大学毕业证成绩单专业办理
zwunae
 
Railway Signalling Principles Edition 3.pdf
Railway Signalling Principles Edition 3.pdfRailway Signalling Principles Edition 3.pdf
Railway Signalling Principles Edition 3.pdf
TeeVichai
 
一比一原版(SFU毕业证)西蒙菲莎大学毕业证成绩单如何办理
一比一原版(SFU毕业证)西蒙菲莎大学毕业证成绩单如何办理一比一原版(SFU毕业证)西蒙菲莎大学毕业证成绩单如何办理
一比一原版(SFU毕业证)西蒙菲莎大学毕业证成绩单如何办理
bakpo1
 
Design and Analysis of Algorithms-DP,Backtracking,Graphs,B&B
Design and Analysis of Algorithms-DP,Backtracking,Graphs,B&BDesign and Analysis of Algorithms-DP,Backtracking,Graphs,B&B
Design and Analysis of Algorithms-DP,Backtracking,Graphs,B&B
Sreedhar Chowdam
 
CME397 Surface Engineering- Professional Elective
CME397 Surface Engineering- Professional ElectiveCME397 Surface Engineering- Professional Elective
CME397 Surface Engineering- Professional Elective
karthi keyan
 
Standard Reomte Control Interface - Neometrix
Standard Reomte Control Interface - NeometrixStandard Reomte Control Interface - Neometrix
Standard Reomte Control Interface - Neometrix
Neometrix_Engineering_Pvt_Ltd
 
Immunizing Image Classifiers Against Localized Adversary Attacks
Immunizing Image Classifiers Against Localized Adversary AttacksImmunizing Image Classifiers Against Localized Adversary Attacks
Immunizing Image Classifiers Against Localized Adversary Attacks
gerogepatton
 
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptx
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxCFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptx
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptx
R&R Consult
 

Recently uploaded (20)

Water Industry Process Automation and Control Monthly - May 2024.pdf
Water Industry Process Automation and Control Monthly - May 2024.pdfWater Industry Process Automation and Control Monthly - May 2024.pdf
Water Industry Process Automation and Control Monthly - May 2024.pdf
 
HYDROPOWER - Hydroelectric power generation
HYDROPOWER - Hydroelectric power generationHYDROPOWER - Hydroelectric power generation
HYDROPOWER - Hydroelectric power generation
 
Governing Equations for Fundamental Aerodynamics_Anderson2010.pdf
Governing Equations for Fundamental Aerodynamics_Anderson2010.pdfGoverning Equations for Fundamental Aerodynamics_Anderson2010.pdf
Governing Equations for Fundamental Aerodynamics_Anderson2010.pdf
 
power quality voltage fluctuation UNIT - I.pptx
power quality voltage fluctuation UNIT - I.pptxpower quality voltage fluctuation UNIT - I.pptx
power quality voltage fluctuation UNIT - I.pptx
 
The Benefits and Techniques of Trenchless Pipe Repair.pdf
The Benefits and Techniques of Trenchless Pipe Repair.pdfThe Benefits and Techniques of Trenchless Pipe Repair.pdf
The Benefits and Techniques of Trenchless Pipe Repair.pdf
 
ethical hacking in wireless-hacking1.ppt
ethical hacking in wireless-hacking1.pptethical hacking in wireless-hacking1.ppt
ethical hacking in wireless-hacking1.ppt
 
English lab ppt no titlespecENG PPTt.pdf
English lab ppt no titlespecENG PPTt.pdfEnglish lab ppt no titlespecENG PPTt.pdf
English lab ppt no titlespecENG PPTt.pdf
 
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)
 
road safety engineering r s e unit 3.pdf
road safety engineering  r s e unit 3.pdfroad safety engineering  r s e unit 3.pdf
road safety engineering r s e unit 3.pdf
 
Architectural Portfolio Sean Lockwood
Architectural Portfolio Sean LockwoodArchitectural Portfolio Sean Lockwood
Architectural Portfolio Sean Lockwood
 
Planning Of Procurement o different goods and services
Planning Of Procurement o different goods and servicesPlanning Of Procurement o different goods and services
Planning Of Procurement o different goods and services
 
Fundamentals of Electric Drives and its applications.pptx
Fundamentals of Electric Drives and its applications.pptxFundamentals of Electric Drives and its applications.pptx
Fundamentals of Electric Drives and its applications.pptx
 
一比一原版(IIT毕业证)伊利诺伊理工大学毕业证成绩单专业办理
一比一原版(IIT毕业证)伊利诺伊理工大学毕业证成绩单专业办理一比一原版(IIT毕业证)伊利诺伊理工大学毕业证成绩单专业办理
一比一原版(IIT毕业证)伊利诺伊理工大学毕业证成绩单专业办理
 
Railway Signalling Principles Edition 3.pdf
Railway Signalling Principles Edition 3.pdfRailway Signalling Principles Edition 3.pdf
Railway Signalling Principles Edition 3.pdf
 
一比一原版(SFU毕业证)西蒙菲莎大学毕业证成绩单如何办理
一比一原版(SFU毕业证)西蒙菲莎大学毕业证成绩单如何办理一比一原版(SFU毕业证)西蒙菲莎大学毕业证成绩单如何办理
一比一原版(SFU毕业证)西蒙菲莎大学毕业证成绩单如何办理
 
Design and Analysis of Algorithms-DP,Backtracking,Graphs,B&B
Design and Analysis of Algorithms-DP,Backtracking,Graphs,B&BDesign and Analysis of Algorithms-DP,Backtracking,Graphs,B&B
Design and Analysis of Algorithms-DP,Backtracking,Graphs,B&B
 
CME397 Surface Engineering- Professional Elective
CME397 Surface Engineering- Professional ElectiveCME397 Surface Engineering- Professional Elective
CME397 Surface Engineering- Professional Elective
 
Standard Reomte Control Interface - Neometrix
Standard Reomte Control Interface - NeometrixStandard Reomte Control Interface - Neometrix
Standard Reomte Control Interface - Neometrix
 
Immunizing Image Classifiers Against Localized Adversary Attacks
Immunizing Image Classifiers Against Localized Adversary AttacksImmunizing Image Classifiers Against Localized Adversary Attacks
Immunizing Image Classifiers Against Localized Adversary Attacks
 
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptx
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxCFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptx
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptx
 

Histogram equalization

  • 1. BI-HISTOGRAM EQUALIZATION wITH A pLATEAU LIMIT FOR DIGITAL IMAGES. MAHESH MOHAN.M.R GECT S1 ECE ROLL NO: 7 GUIDE : Dr.V.S.SHEEBA OM NAMA SIVAYA
  • 2. OBJECTIVE . TO FAMILARIZE WITH .HISTOGRAM EQUALIZATION .DIFFERENT EQUALIZATION METHODS .THEIR DRAWBACK AND HOW IT IS RECTIFIED.
  • 3. FLOw OF SEMINAR. 1.WHAT IS A DIGITAL IMAGE? 2.WHAT IS A HISTOGRAM? 3.WHAT IS HISTOGRAM EQUALIZATION? 4.DIFFERENT EQUALIZATION METHODS AND ITS DRAWBACK. 5.HOW DRAWBACK OF EACH METHOD IS RECTIFED?
  • 5. dGray Image Image wHAT IS A GRAy SCALE IMAGE? 243 121 . 34 21 . . . Gray level matrix 0 255
  • 6. Image matrix Image wHAT IS A COLOUR IMAGE? 234 212 123 135 231 233 . 121 222 . . 243 121 . . . . 112 167 . . . . Red matrix Green matrix Blue matrix . .
  • 7. wHAT IS A HISTOGRAM? Consider a 5x5 image with integer intensities in the range between zero and seven: 0 7 3 2 3 0 0 0 6 7 7 7 2 2 0 1 1 0 4 1 0 0 7 4 1 Image matrixImage 0 1 2 3 4 5 6 7 Gray scale Black White
  • 8. wHAT IS A HISTOGRAM? Consider a 5x5 image with integer intensities in the range between one and eight: 0 7 3 2 3 0 0 0 6 7 7 7 2 2 0 1 1 0 4 1 0 0 7 4 1 Image matrixImage 0 1 2 3 4 5 6 7 Grey scale Black White Number of pixel with intensity value 0 [h(r0)] = 8
  • 9. wHAT IS A HISTOGRAM? 0 7 3 2 3 0 0 0 6 7 7 7 2 2 0 1 1 0 4 1 0 0 7 4 1 Image matrixImage 0 1 2 3 4 5 6 7 Grey scale Black White Number of pixel with intensity value 0 [h(r0)] = 8 Similarly for 1 h(r1) = 4
  • 10. wHAT IS A HISTOGRAM? 0 7 3 2 3 0 0 0 6 7 7 7 2 2 0 1 1 0 4 1 0 0 7 4 1 Image matrixImage Similarly INTENSITY r 0 1 2 3 4 5 6 7 NUMBER of pixels of r h(r)   h(r0)=8   h(r1)=4 h(r2)=3  h(r3)=2  h(r4)=2  h(r5)=0  h(r6)=1   h(r7)=5
  • 11. r wHAT IS A HISTOGRAM? Image matrix 0 1 2 3 4 5 6 7 HISTOGRAM Intensity values Number of pixels of intensity r r 0 1 2 3 4 5 6 7 h(r)   8     4    3     2     2     0     1     5 Histogram plots the number of pixels for each intensity value. h(r)
  • 12. What is a histogram? r 0 1 2 3 4 5 6 7 h(r) 8 4 3 2 2 0 1 5 p(r) h(r)/(5*5) 8/25 4/25 3/25 2/25 2/25 0/25 1/25 5/25 HISTOGRAM - h(r) - Y axis - number of intensities NORMALIZED HISTOGRAM - p(r) - Y axis - probability of intensities
  • 13. SAMPLE IMAGES AND ITS HISTOGRAM Bright image Intensity range 0 - 255
  • 14. SAMPLE IMAGES AND ITS HISTOGRAM Bright image Intensity range 0 - 255 0 50 100 150 200 255 Intensity No:ofpixels DARK BRIGHT h(r)
  • 15. SAMPLE IMAGES AND ITS HISTOGRAM Dark image Intensity range 0 - 255
  • 16. SAMPLE IMAGES AND ITS HISTOGRAM Dark image Intensity range 0 - 255 0 50 100 150 200 255 Intensity No:ofpixels h(r)
  • 17. SAMPLE IMAGES AND ITS HISTOGRAM Low contrast image Intensity range 0 - 255
  • 18. SAMPLE IMAGES AND ITS HISTOGRAM Light image Intensity range 0 - 255 0 50 100 150 200 255 Intensity No:ofpixels h(r)
  • 19. SAMPLE IMAGES AND ITS HISTOGRAM Bright image Dark image Low contrast image
  • 20. SAMPLE IMAGES AND ITS HISTOGRAM High contrast image Intensity range 0 - 255 0 50 100 150 200 255 Intensity No:ofpixels h(r)
  • 21. CoNCEPt oF histogram EQUaLiZatioN ORIGINAL IMAGE EQUALIZED IMAGE MAXIMIZES ENTROPY OF AN IMAGE. s1 s2
  • 22. thEorY BEhiND histogram EQUaLiZatioN TRANSFORMATION FUNCTION THAT MAPS THE INPUT INTENSITY TO ALL AVAILABLE INTENSITIES. I/p intensity O/p intensity
  • 23. THEORY BEHIND HISTOGRAM EQUALIZATION ORIGINAL IMAGE EQUALIZED IMAGE s1 s2
  • 24. THEORY BEHIND HISTOGRAM EQUALIZATION CUMULATIVE DISTRIBUTION FUNCTION T(r) 0 50 100 150 200 255 [76 – 213] [0 – 48] [15 – 100] [25 – 125] O/P INTENSITY = X0 + [( Xl-1 –X0 )*C(x)] I/P intensity
  • 26. GLOBAL HISTOGRAM EQUALIZATION OBTAIN HISTOGRAM OBTAIN PDF OBTAIN CDF OBTAIN TRANSFORMATIO N FUNCTION MAPPING OF NEW INTENSITY VALUES NEW HISTOGRAM Original histogram M*N PDF 1.. CDF 1 x0 XL-1 O/P x0 XL-1 MappingTransformation function t1 t2 t2 New histogram t1t1 t2 t2t1t2t1
  • 28. GLOBAL HISTOGRAM EQUALIZATION DRAWBACK DO NOT CONSERVE THE MEAN. WHY MEAN IMPORTANT? Video frames GHE
  • 29. THEORY OF BIHISTOGRAM EQUALIZATION HISTOGRAM EQUALIZED SEPERATELY AROUND MEAN. THUS CONSERVE THE MEAN. ORIGINAL HISTOGRAM BIHISTOGRAM EQUALIZED
  • 30. BIHISTOGRAM EQUALIZATION OBTAIN PDF (lower subimage)[X0-Xm] OBTAIN CDF OBTAIN TRANSFORMATIO N FUNCTION MAPPING OF NEW INTENSITY VALUES NEW HISTOGRAM DIVIDE HISTOGRAM WITH RESPECT TO INTENSITY MEAN (X m ). OBTAIN HISTOGRAM OBTAIN PDF (upper subimage)[Xm-Xl-1] OBTAIN CDF OBTAIN TRANSFORMATIO N FUNCTION MAPPING OF NEW INTENSITY VALUES + GHE GHE Partition Merging
  • 32. BIHISTOGRAM EQUALIZATION DRAWBACK LEVEL SATURATION DUE TO HIGH PROBABLE INTENSITY VALUES. BHE EXAMPLE WHY IT HAPPENS ?
  • 33. THOERY OF BIHISTOGRAM EQUALIZATION WITH A PLATEAU LIMIT . BIHISTOGRAM CLIPPING HISTOGRAM ABOVE PLATEAU LIMIT TL PLATEAU LIMITS FOR LOWER HISTOGRAM. TU PLATEAU LIMITS FOR UPPER HISTOGRAM. SELECT PLATEAU LIMIT
  • 34. BIHISTOGRAM EQUALIZATION WITH A PLATEAU LIMIT OBTAIN PDF (lower subimage)[X0-Xm] OBTAIN CDF OBTAIN TRANSFORMATION FUNCTION MAPPING OF NEW INTENSITY VALUES NEW HISTOGRAM DIVIDE HISTOGRAM WITH RESPECT TO INTENSITY MEAN (X m ). OBTAIN HISTOGRAM OBTAIN PDF (upper subimage)[Xm-Xl-1] OBTAIN CDF OBTAIN TRANSFORMATION FUNCTION MAPPING OF NEW INTENSITY VALUES + GHE GHE Partition Merging CLIP WRT AMPLITUDE MEAN CLIP WRT AMPLITUDE MEAN Clipping
  • 35. BIHISTOGRAM EQUALIZATION WITH A PLATEAU LIMIT RESULTS BHEPL
  • 36. SIMULATION RESULTS TEST IMAGES GLOBAL HISTOGRAM EQUALIZATION BI-HISTOGRAM EQUALIZATION BIHISTOGRAM EQUALIZATION WITH PLATEAU LIMIT DARK 86 126 82 91 BRIGHT 143 126 154 153 LOWCONTRAST 77 124 99 103 MEAN VALUES
  • 37. SIMULATION RESULTS LEVEL SATURATION TEST IMAGES BI-HISTOGRAM EQUALIZATION BIHISTOGRAM EQUALIZATION WITH PLATEAU LIMIT WHITE DOT YES NO
  • 38. d WHY GRAY SCALE IMAGES INSTEAD OF COLOUR IMAGES? .
  • 39. CONCLUSIONHistogram? IN AN IMAGE NOTHING WORSE MORE THAN LOW CONTRAST GLOBAL HISTOGRAM EQUALIZATION NOTHING WORSE MORE THAN MEAN CONSERVATION BI-HISTOGRAM EQUALIZATION NOTHING WORSE MORE THAN ………………? NOTHING WORSE MORE THAN LEVEL SATURATION BI-HISTOGRAM EQUALIZATION WITH PLATEAU LIMIT
  • 40. REFERENCESStogram? Bi-Histogram Equalization with a Plateau Limit for Digital Image Enhancement Chen Hee Ooi, Student Member, IEEE, Nicholas Sia Pik Kong, Student Member, IEEEand Haidi Ibrahim, Member, IEEE IEEE Transactions on Consumer Electronics, Vol. 55, No. 4, NOVEMBER 2009 Contrast Enhancement Using Brightness Preserving Bi-Histogram Equalization YEONG-TAEG KIM, MEMBER, IEEE Color Image Enhancement Using Brightness Preserving Dynamic Histogram Equalization Nicholas Sia Pik Kong, Student Member, IEEE, and Haidi Ibrahim, Member, IEEE. Preserving brightness in histogram equalization based contrast enhancement techniques Soong-Der Chen a, Abd. Rahman Ramli Digital image processing by Gonzalez and Woods
  • 42. • Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Vivamus et magna. Fusce sed sem sed magna suscipit egestas. • Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Vivamus et magna. Fusce sed sem sed magna suscipit egestas. 1
  • 43. • Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Vivamus et magna. Fusce sed sem sed magna suscipit egestas. • Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Vivamus et magna. Fusce sed sem sed magna suscipit egestas. 1