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IMAGE PROCESSING
| Date post: | 24-May-2015 |
| Category: |
Education |
| Upload: | paramjeet-singh-jamwal |
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IMAGE
PROCESSING
IMAGE
PROCESSING
IMAGE
PROCESSING
IMAGE
An artefact
Similar appearance – subject or person
A flower
PROCESSING
Act of converting
One form to another
C E A A B C D F D B E F G HH I G J I J
Act of converting
An image
Captured form to another form
IMAGE PROCESSING
3FormatComparison
Image Processing : Contents
1Human Vision System
2Computer
Vision System
4Image
Enhancements
Human Vision System
1) The colours2) The eye3) Perception4) From perception to processing5) Confusing the “ eye ”
1
Human Vision System : The Colours
Primary colours :
Combined to make any range of colours
Additive combination
red green blue
Subtractive combination
cyan magenta yellow
Additive colour mixing
Subtractive colour mixing
Human Vision System : The eye
Human Vision System : Perception
Rod cells ( brightness )
Cone cells ( colours )
During Processing
• Boundaries are most important
• We seem to use prior knowledge
Human Vision System : From perception to processing
When you look at this, you probably see a triangle. But there is no one there!
During Processing
• Boundaries are most important
• We seem to use prior knowledge
Human Vision System : From perception to processing
When you first read this, what does it say: A Bird In The Bush . Read this more carefully you will find that it says A Bird In The The Bush !!!
Human Vision System : Confusing the “ eye ”
The Zollner Illusion
are the diagonals parallel ?
The Ebbinghaus Illusion
are the centre circles of same size ?
2 Computer Vision System
1) Greyscale images2) Colour images3) CMYK colour model4) HSV colour model
Computer Vision System : Greyscale images
135 66 77 88 123 122 156 215 213 234 112 123 145.. .. .. .. .. .. .. .. .. ..
Bit 0(LSB)
Bit 1
Bit 2
Bit 3
Bit 4
Bit 5
Bit 6
Bit 7(MSB)
135 = 1 0 0 0 0 1 1 1 66 = 0 1 0 0 0 0 1 0
Bit 0(LSB)
Bit 7(MSB)
Computer Vision System : Greyscale images
8-bit greyscale
4-bit greyscale
2-bit greyscale
1-bit greyscale
Computer Vision System : Colour images
The RGB colour model mapped to a cube.
A fully saturated faces of a 24-bit RGB cube , unfolded in a plane
Computer Vision System : Colour images
Red component of a colour image
Computer Vision System : Colour images
Green component of a colour image
R
Computer Vision System : Colour images
Blue component of a colour image
R
G
Computer Vision System : Colour images
Original colour image
R
G
B
Computer Vision System : Colour images
24-bit RGB
16-bit RGB
9-bit RGB
3-bit RGB
Computer Vision System : CMYK colour model
Cyan component of a colour image
Computer Vision System : CMYK colour model
Magenta component of a colour image
C
Computer Vision System : CMYK colour model
Yellow component of a colour image
C
M
Computer Vision System : CMYK colour model
Black component of a colour image
C
M
Y
Computer Vision System : CMYK colour model
Original colour image
C
M
Y
K
Computer Vision System : HSV colour model
The RGB colour model
The corresponding HSL and HSV colour models
Computer Vision System : HSV colour model
Hue Saturation
Brightness
OriginalImage
3
Format Comparison
1) Bitmap2) Graphics Interchange Format3) Portable Network Graphics4) JPEG5) JPEG 20006) Tagged Image File Format7) Comparison
Computer Vision System : Bitmap
Extension : bmp
Height : 1280
Width : 800
Size : 3001 KB
% Size : 100.00 %Comparedto BMP
Unique : 188556coloursused
Computer Vision System : Graphics Interchange Format
Extension : gif
Height : 1280
Width : 800
Size : 355 KB
% Size : 11.83 %Comparedto BMP
Unique : 256coloursused
Computer Vision System : Portable Network Graphics
Extension : png
Height : 1280
Width : 800
Size : 1962 KB
% Size : 65.37 %Comparedto BMP
Unique : 188556coloursused
Computer Vision System : JPEG
Joint Photographic Experts Group
Extension : jpg
Height : 1280
Width : 800
Size : 538 KB
% Size : 17.92 %Comparedto BMP
Unique : 192292coloursused
Computer Vision System : JPEG 2000
Extension : jp2
Height : 1280
Width : 800
Size : 913 KB
% Size : 30.42 %Comparedto BMP
Unique : 192292coloursused
Computer Vision System : Tagged Image File Format
Extension : tif
Height : 1280
Width : 800
Size : 3001 KB
% Size : 100.00 %Comparedto BMP
Unique : 185556coloursused
Computer Vision System : Comparison
BMP; 3001
GIF; 355PNG; 1962
JPG; 538
JPG2000; 913
TIFF; 3001BMP;
188556GIF; 256
PNG; 188556
JPG; 192292
JPG2000; 192292
TIFF; 185556
File Size ( KB ) No of UniqueColours
4 Image Enhancements
1) Histogram equalization2) Brightness adjustment3) Curved level adjustment4) Gamma adjustment5) Noise reduction6) Homomorphic filtering7) Contrast stretching
Image Operations : Histogram equalization
OriginalImage
Image Operations : Histogram equalization
Value Count Value Count Value Count Value Count Value Count
52 1 64 2 72 1 85 2 113 1
55 3 65 3 73 2 87 1 122 1
58 2 66 2 75 1 88 1 126 1
59 3 67 1 76 1 90 1 144 1
60 1 68 5 77 1 94 1 154 1
61 4 69 3 78 1 104 2
62 1 70 4 79 2 106 1
63 2 71 2 83 1 109 1
Image Operations : Histogram equalization
Value cdf Value cdf Value cdf Value cdf Value cdf52 1 64 19 72 40 85 51 113 6055 4 65 22 73 42 87 52 122 6158 6 66 24 75 43 88 53 126 6259 9 67 25 76 44 90 54 144 6360 10 68 30 77 45 94 55 154 6461 14 69 33 78 46 104 5762 15 70 37 79 48 106 5863 17 71 39 83 49 109 59
Image Operations : Histogram equalization
OriginalImage
EqualizedImage
Image Operations : Histogram equalization
OriginalImage
EqualizedImage
Image Operations : Histogram equalization
OriginalImage
EqualizedImage
Image Operations : Brightness adjustment
OriginalImage
AdjustedImage
Image Operations : Curved level adjustment
Image Operations : Curved level adjustment
Image Operations : Gamma adjustment
OriginalImage
AdjustedImage
Image Operations : Gamma adjustment
Image Operations : Noise reduction
Salt & Pepper Noise
ImpulseNoise
GaussianNoise
Image Operations : Noise reduction
Image After noise reduction
Image Operations : Homomorphic filtering
OriginalImage
FilteredImage
Image Operations : Contrast stretching
Image Operations : Contrast stretching
OriginalImage
StretchedImage
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Image Processing
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PROCESSING
