Digital Image Processing

1
Digital Image Processing

• ????? ???????
• ???
• Simplified approach to Image Processing
• (classical modern techniques in C)

2
DIP (Digital Image Processing)
? ?
Digtal ???? ???? ??? ???? ???? ??? ??, ????, ???
??? ?? ??
? ? ?
(1) ?? ??(Image Manipulation) (2) ?? ??(Image
Analysis) (3) ?? ??(Image Recognition) (4) ??
??(Image Communication)
3
DIP (Digital Image Processing)
?? ??

1. ??? ??
2. ??? ??
3. ???? ??
4. ?? ???(Factory Automation)
5. ?? ?? ?? ???(Medical Diagnostic Imaging)
6. ???/?? ??

4
DIP (Digital Image Processing)
???????? ??
5
DIP (Digital Image Processing)
??? ??? ??
(1) ??? ??? (2) ????? ???? (3) ???, ????
???? (4) ????? ??? ???? (5) ??? ?? ? ???? ????
6
DIP (Digital Image Processing)
??? ????
7
DIP (Digital Image Processing)
??? ???(Sample)
8
DIP (Digital Image Processing)
??? ??? ?? ??? ??
9
DIP (Digital Image Processing)
???(Quantization)
10
DIP (Digital Image Processing) - Color Space
?????? ???? ??? ??
(1)???? (2)??? ?? (3)????

• ?? ??
• ??? ??? ? ??(?, ?)?? ? ??
• ??, ?? ??, ?? ?? ??? ??
• ?? ??? ???? ????? ???? ??? ?? ??? ?? ????? ?? ???
  ??

11
DIP (Digital Image Processing) - Color Space
(2) ??? ??

• - ???? ?? ??? ???? ??(?? ??)
• 0 f(x, y) 2n-1 ??? ??? ?? ? ??
• ?? ??? ????? ??? ??? ??? ??

(3) ?? ??
- ???? ?? - 19?? ??? ???? ?? ??? ??(R),
??(G), ??(B)? ???? ??? ? ??? ?? - ?? ???
??? ?? ??? ??? ?? ??? ?? - ?? ??? ??? ?? -gt ??
?? ?? sqrt ( red2 green2 blue2) /
sqrt(3)
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DIP (Digital Image Processing) - Color Space
?? ???? Gray ???? ??
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DIP (Digital Image Processing) - Color Space
??? ??? ??? ?
????? ??? ?
???? ??? ???? ??? ??? ???
???? ??? ?
????? ??? ? ?? ??? ?
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DIP (Digital Image Processing) - Color
Space(Image file)
??? ??? ?? ?? ?? 1
BMP ?? ??

• - MS ?? ??? ?? ???? ??? ????? ???? ??
• - ??? ? ?? ??? ???? ??? ???? ?? ???? ??
• - ???? ??? ??? ??
• - ????? ????? ???? ?? ????? ??? ??? ?

PCX ?? ??

• - ZSoft? ????? PC paintbrush ????? ?? ?? ??
• - ??? ??? ?? ??
• - ??? 128 ???? ??

15
DIP (Digital Image Processing) - Color
Space(Image file)
??? ??? ?? ?? ?? 2
GIF (Graphics Interchange Format) ?? ??
- ??? ?? ????? ?????? 1987?? ???? ?? ? ??? ??
?? ??? ??? ?? - LZW(Lempel Ziv Welch) ?? ???
???? ???? ?? ????? ??
JPEG (Joint Photographic Experts Group) ?? ??
- ISO/IEC? CCITT? ?? ??? ? ?? ?? ??? ???? ???
???? ??? ??? ??? ???? ?? ??? ?? - ?? ??? DCT ??
?? ??? ???? ???? ?? ?? ??? ??? ??? ???? ? ??
???? ??? ??? ??? ????? ?? ???? ????? ??
16
DIP (Digital Image Processing) - Color
Space(Image file)
??? ??? ?? ?? ?? 3
TIFF (Tagged Image File Format) ?? ??
- TIFF? ??? ??? ???? ??? ????? ??? ?? ?? ??
- ?? ???? ?? ?? ??? ???? ?????? ???
(descriptor) - ?? ??? ????? ??? ???? ??? ???
???? ?? ?? ??? ??? ?? - 232 ??? ????? ????
????? ??? ????? ????? ????? - ?? ??? ?? ??
??? ?? ?? ?? ??? ??? ???? ????? ???? ?
17
DIP (Digital Image Processing) - Color Space
Color
???? ????
RGB
CMY
YCbCr
YIQ
HSI
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DIP (Digital Image Processing) - Color Space(RGB)
RGB

• Color Camera/Monitor ?? ??
• ??(Red),
• ??(Green)
• ??(Blue) ??

Brighteness 0.2999R 0.587G 0.114B
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DIP (Digital Image Processing) - Color Space(RGB)
??? ????? RGB ?? ??
20
DIP (Digital Image Processing) - Color Space(CMY)
CMY

RGB?? ????? ?? ????
?? ???? ??????? ?? CMYK ?? CMY? K(???? ??
??) ?? ??
C 1.0 R M 1.0 - G Y 1.0 - B
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DIP (Digital Image Processing) - Color Space(CMY)
RGB ??? CMY ???? ??
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DIP (Digital Image Processing) - Color Space(HIS)
Color
RGB ??? HSI ???? ??
23
DIP (Digital Image Processing) - Color Space(HIS)
HSI??
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DIP (Digital Image Processing) - Color Space(YUV)
YUV

• Color TV? ???? ?? ??
• (PAL/SECAM)

Y 0.299R 0.587G 0.114B U -0.147R -0.289G
0.437B V 0.615R - 0.515G - 0.100B
?? ??
R 1.000Y 0.000U 1.403V G 1.000Y - 0.344U
- 0.714V B 1.000Y 1.773U 0.000V
? ?? ??
25
DIP (Digital Image Processing) - Color Space(YUV)
RGB ??? YUV ???? ??
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DIP (Digital Image Processing) - Color Space(YIQ)
YIQ

• Color TV? ???? ?? ??
• (PAL/SECAM)

Y 0.299R 0.587G 0.114B I 0.596R - 0.274G
- 0.322B Q 0.211R - 0.523G - 0.312B
?? ??
R - 1.129Y 3.306I - 3.000Q G 1.607Y -
0.934I 0.386Q B 3.458Y - 3.817I 5.881Q
? ?? ??
27
DIP (Digital Image Processing) - Color Space(YIQ)
RGB ??? YIQ ???? ??
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DIP (Digital Image Processing) - Color
Space(YCbCr)
YCbCr
?? ??(MPEG)?? ???? ?? ??
Y 77R/256 150G/256 29B/256 Cb 131R/256 -
110G/256 - 21B/256 128 Cr 131R/256 -
44R/256 - 87G/256 128
?? ??
29
DIP (Digital Image Processing) - Color
Space(YCbCr)
RGB ??? YCbCr ???? ??
30
DIP (Digital Image Processing)
??
Point Processing
Area Processing
Topological Processing
Frame Processing
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DIP (Digital Image Processing) - Point
Processing (????? ? ??, ?????)
Point Processing
??(pixel)? ?? ?? ?? ???? ??? ???? ???? ??? ??
??? ??? ?? ? ??? ??
??? ??
???? 0 ?? 255 ??? ??? ?? (0 ???, 255 ??)
24bit? ?? (Red, Blue, Green Channel ? ??? 8bit?
??)
?? ??
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DIP (Digital Image Processing) - Point
Processing (????? ? ??, ?????)
Gray ???? ??? ??
Clamping
??? ??? ?? 256??? ??? ???, ??? ????? ??? ?? ???
?? ???? ?? ???? 255? ???? ??? 255?, 0??? ?? 0??
???? ?
33
DIP (Digital Image Processing) - Point
Processing (????? ? ??, ?????)
????? (Histogram)
??? ???? ??? ?? ??? ??? ??? ?
? ?
34
DIP (Digital Image Processing) - Point
Processing (????? ? ??, ?????)
? ?

• ? ??? ????? ????? ??? ??? ??? ??
• (??? ??)? ????
• (2) ?? ??? ?? ?????? ?? ? ??
• (3) ? ??? ???? ?????? ??? ?? ??????
• ?? ? ??
• (4) ?????? ????? ???? ?? ?????? ????
• ??? ? ??

? ?
??? ???? ??
??? ???? ? ??? ??? ????? ???? ?? ??? ??? ??
????? ??? ??? ??? ??? ?????? ?? ???? ??
????? ???? ??
35
DIP (Digital Image Processing) - Point
Processing (????? ? ??, ?????)
? ?
??? ??
36
DIP (Digital Image Processing) - Point
Processing (????? ? ??, ?????)
????? ???(histogram equalization)
?? ???? ??? ???? ?????? ??? ??? ??? ?? ???? ??
??? ??? ?? ?? ???? ??? ??
? ?
????? ??
?????? ??? ? ? ??
?? ??? ???? ?? ?? ??
37
DIP (Digital Image Processing) - Point
Processing (????? ? ??, ?????)
????? ???(histogram equalization) ?
38
DIP (Digital Image Processing) - Point
Processing (????? ? ??, ?????)
?????? ??? ? ????? ??? ??
39
DIP (Digital Image Processing) - Point
Processing (????(Contrast),????)
???? ????

• ???? ??? ??? ??? ??
• ??(??) ?? ???
• ?? ??? ????? ?? ??? ??? ??
• Contrast ?? ??? ? ??? ??? ????? ????
• ??? ???? ????? ??
• (1) Sliding ???? ?? ?? ???? ???? ?? ?
• (2) ????(stretching) ?? ???? ?????
  ????
• ???
  ??? ?? ??? ???
• 
  ????? ?????? ??
• ???
  ?

40
DIP (Digital Image Processing) - Point
Processing (????(Contrast),????)
???? ???? ????
?? ???? ????
??
??? ???? ???? ?????? ?? ??? ??
??
old pixel - low new pixel
------------ 255 high - low
?? ???? ????
41
DIP (Digital Image Processing) - Point
Processing (????(Contrast),????)
???? ???? ????
??? ?? (ends-in search)
??
?? ??? ??? ???? ?????? ?? ??? ???? ??? ??? ??
0 (? x lt low) output 255
(x-low)/(high - low) (? low lt x lt high)
255 (? high lt x)
??
??-? ??
42
DIP (Digital Image Processing) - Point
Processing (????(Contrast),????)
????
????
?? ??? ??? ???? ?? ???? ??? ????? ??? ?
y x
???
y 255 x
???
???? ???
43
DIP (Digital Image Processing) - Point
Processing (????(Contrast),????)
?? ??
? ?
???? ??? ?? ??? CRT? ???? ???? ???.(?CRT? ??? ??)
?? ???? ??
44
DIP (Digital Image Processing) - Point
Processing (????(Contrast),????)
?????? / ???? ?? ??
? ?
?? ?? ???, ???? ??
?????? / ???? ??
45
DIP (Digital Image Processing) - Point
Processing (????(Contrast),????)
??????
? ?
??? ?? ? ?? ?? ??? ??
?????? ??? ??
46
DIP (Digital Image Processing) - Point
Processing (????(Contrast),????)
???? ??? ??
? ?
???? ??? ??? ?? ? ???
???? ??? ??? ??
47
DIP (Digital Image Processing) - Point
Processing (????(Contrast),????)
?? ???
? ?
??? ??? ?? ??? 0?? ???
?? ???? ??? ??? ??
48
DIP (Digital Image Processing) - Point
Processing (????(Contrast),????)
??? ???
? ?
?? ?? ???? ?? ?? ??? ??
??? ???? ??? ??? ??
49
DIP (Digital Image Processing) - Point
Processing (????(Contrast),????)
?? ?? ??
? ?
?? ??? ??? ???? ????? ?? ??
?? ?? ??? ??
50
DIP (Digital Image Processing) - Point
Processing (????(Contrast),????)
????? ?? / ???? ??
? ?
??? ????? ?? ??
????? ?? / ???? ??? ??
51
DIP (Digital Image Processing) - Area Processing
1(??? ?? ??)
frequency ??? ??
52
DIP (Digital Image Processing) - Area Processing
1(Convolution)
Convolution ??? ??
????
?? ??? ??? ?? ?? ???? ??? ?? ?? ??? ?? ???? ????
??
Convolution technique
?? ??? ??? ??? ??? ??? ???? ?? ?? ?? ??? ???? ??
? ?
?? ???. ????? ?? ?? ?? ?? ?? ?? ??
53
DIP (Digital Image Processing) - Area Processing
1(Convolution)
Convolution technique ??? ?
? Embossing - ????? ??? ?
? Bluring - ??? ????
? Sharpning - ??? ??? ????? ?? ??
? Edge Detection - ??? ??
? Spatial Filtering (?????)
54
DIP (Digital Image Processing) - Area Processing
1(Embossing)
??? ?? (Embossing Effect)
???? ??? ??? ?? ?
? ?
???? 0, ?? 0
???? ??
-1 0 0
0 0 0
0 0 1
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DIP (Digital Image Processing) - Area Processing
1(Embossing)
?????? ??? ??? ?? ??

• RGB ?? ? HSI ?? ?? ??
• ? ???? ?? ? RGB ?? ?? ??

2) RGB ?? ? ? ?? ?? ? ? ?? ?? ?? ? RGB ?? ???
? ??? ??? 1)?? ??? I ?? V ??? ???? ??? HSI ?????
??? H? ? ??? ?? ??? ??? ????? ? ???? ????.
56
DIP (Digital Image Processing) - Area Processing
1(Embossing)
?????? ??? ??? ?? ??
1)? ?? ??? ?? ??? ???
2)? ?? ??? ?? ??? ???
57
DIP (Digital Image Processing) - Area Processing
1(Bluring)
??? (Bluring) ??
??? ??? ??? ???? ??? ?(??? ?? ???)
? ?
55 ???
33 ???
1/9 1/9 1/9
1/9 1/9 1/9
1/9 1/9 1/9
1/25 1/25 1/25 1/25 1/25
1/25 1/25 1/25 1/25 1/25
1/25 1/25 1/25 1/25 1/25
1/25 1/25 1/25 1/25 1/25
1/25 1/25 1/25 1/25 1/25
?? ???? ?? 1 ? MM ???? ?? ? ??? 1/(MM)
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DIP (Digital Image Processing) - Area Processing
1(Bluring)
???? ???(Bluring) ??
33 ???? ??
1/16 1/8 1/16
1/8 1/4 1/8
1/16 1/8 1/16
?? ???? ?? 1
?? ?????? ???? ?? ???? ??? ??? ??? ???? ?? ??
BUT ??? ??? ??
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DIP (Digital Image Processing) - Area Processing
1(Bluring)
?? ???(Bluring)
??(noise)
???? ???? ????? ???? ?? ?? ?? ??? ?
???? ??(Gaussian Noise)
???? ??? ???? ??? ??
Impulse Noise Spike Noise
0? 255 ?? ???? ??? ???? ???? ??? ????? ?? ??? ??
?? ??? ? ?? ?????(Median filter)? ??
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DIP (Digital Image Processing) - Area Processing
1(Bluring)
???? ???
????? ???
???? ???
1) ???
???? ???? ?? ? ?) ?, ?? ?
2) ???
???? ???? ? ? ?) ?, ??, ???, ??? ?
61
DIP (Digital Image Processing) - Area Processing
1(Sharpning)
??? (Sharpning) ??
??? ???? ? (??? ?? ???)
? ?
???? ??? ?? ?? ?? ???
???? ?? ???
0 -1 0
-1 5 -1
0 -1 0
-1 -1 -1
-1 9 -1
-1 -1 -1
-1/9 -1/9 -1/9
-1/9 8/9 -1/9
-1/9 -1/9 -1/9
lt33 ???? ??,?? ???? ? 1gt
lt?? ???? ? 0gt
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DIP (Digital Image Processing) - Area Processing
1(Sharpning)
???
63
DIP (Digital Image Processing) - Area Processing
1(Sharpning)
??? (Sharpning)
unsharp masking
(? ??) (??? ?? ???? ??)
??? ??(high-boost) ???
a(? ??) (??? ?? ???? ??)
???? ?? ???
High-Boost aOriginal Lowpass
-a/ 9 -a/ 9 -a/ 9
-a/ 9 -w/ 9 -a/ 9
-a/ 9 -a/ 9 -a/ 9
? a1 ??? ?? ?? ??? ? agt1 ? ??? ??? ?? ???
? ??? ??? w9a -1 ?
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DIP (Digital Image Processing) - Area Processing
1(Sharpning)
??? (Sharpning)
??? ??
??? ?? ??? ??? ?? ???(a1.2) ??? ?? ???(a1. 5)
1) ?? ?? ??? ?? 2) unsharp masking 3)
high-boost filtering 4) Laplacian filter

• ??? ??? ??? ????? ??? ?? ???? ???? ?? ????
  ??(noise)? ??

65
DIP (Digital Image Processing) - Area Processing
1(BluringSharpning)
???? ???? ??
Bluring
- ??? ??? ?? ?? / ???? ?? ?? - ?? ?? ?? / ?? ????
?? 1 - ??? ?? ??, ??? ?? ?? ???
Sharpning
- ??? ??? ?? ?? / ?? ?? ??? ?? - ?? ?? ??? ?? ??
?? ??? ? ??? ?? ?? ?? ???? ?? zero
? unsharp masking (???) (??? ?? ???? ??)
? ??? ?? ?? (???? ?? ??)(??? ?? ???) - ????
??? ???? ??
66
DIP (Digital Image Processing) - Area Processing
2(Edge Extraction)
??(Egde)

• ??? ??? ??? ?? ??? ?? ???, ?? ??? ??? ??? ???? ??
• ???? ?? ??? ??(Boundary)? ???? ?
• ??(Shape), ???(Direction)? ??? ? ?? ? ?? ?? ???
  ??? ?? ??

??? ?? ?? ??
1) ????? (homogenity operator) 2) ????
(difference operator) 3) ??? ??/??? ???
???(threshold) ??
67
DIP (Digital Image Processing) - Area Processing
2(Edge Extraction)
????? ??? ??? ?? ??
?? ??(edge extraction)
????(image segmentation)? ??
???????? ??
- ?? ???? ?? ?? ??? - ??? ???? ??? ??? ??? ???? ??
???????? ??
8? ????? ??? ? ??? ?? ????? ?? ??
68
DIP (Digital Image Processing) - Area Processing
2(Edge Extraction)
????? ??? ??? ?? ??
??

• 33 ?? ??????? ??? 8??? ?? ??
• 2) ? ??? ??? ? ?? ? ?? ??? ????? ??

69
DIP (Digital Image Processing) - Area Processing
2(Edge Extraction)
????? ??? ??? ?? ??
70
DIP (Digital Image Processing) - Area Processing
2(Edge Extraction)
???? ??? ??? ?? ??
????? ??? ? ?? ???? ???? ?? ???? ?? (4?? ??)
71
DIP (Digital Image Processing) - Area Processing
2(Edge Extraction)
???? ??? ??? ?? ??
72
DIP (Digital Image Processing) - Area Processing
2(Edge Extraction)
???? ??? ?? ??/??
?? ??? ??? ??? ?? ?? ???? ?? ?? - ?? ???
???, ?? ??? ??
??? ??? ??
1) ?? ???? ??? ?? ?) ?? ???? 48? ????,
48??? 255? 48??? 0?? ? ?? 2) ?? ???? ??? ??
?) ?? ??????, 48??? 0, 192??? 255, ??? ???
? ??
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DIP (Digital Image Processing) - Area Processing
2(Edge Extraction)
???? ??? ?? ??/??
74
DIP (Digital Image Processing) - Area Processing
2(First-Order Differential operator)
1? ?? (First-Order Differential operator)
Gradient Edge Dector

• ??? ???? ???? ???? ???? ???, ???? ????? ??? ?? ??
• ??? ????? ???, ?? ?? ???(???)? ??

1??? ?? ??
1????? abs(??????)abs(??????)
? sqrt( ??????2 ??????2) H(x,y)
abs(H_r(x,y)) abs(H_c(x,y))
?sqrt(H_r(x,y)2 H_c(x,y)2)
(r, c ??, ??)
75
DIP (Digital Image Processing) - Area Processing
2(First-Order Differential operator)
1? ??? ??
76
DIP (Digital Image Processing) - Area Processing
2(First-Order Differential operator)
Roberts
??
?? ???? ???? ?? ????? ????.
??
??? ?? ? ??? ?? ??. ??? ????.
77
DIP (Digital Image Processing) - Area Processing
2(First-Order Differential operator)
Prewitt
??
??? ?? ??? ??? ?
??
??? ??? ??? ??? ???? ??.
78
DIP (Digital Image Processing) - Area Processing
2(First-Order Differential operator)
Sobel
??
??? ?? ??? ??? ?
??
??? ??? ??? ??? ???? ??.
79
DIP (Digital Image Processing) - Area Processing
2(Second-Order Differential operator)
2? ?? (Second-Order Differential operator)
1? ??
???? ??? ???? ??? ??? ???? ??
2? ??
?? ??? ???? ???? ??
2? ??? ??
? ?
??? ?? ???? ???? ??? ?? ?
80
DIP (Digital Image Processing) - Area Processing
2(Second-Order Differential operator)
Laplacian (?????)
- ??? ??? ??? ??, ?? ??? ?? ? ?? ??? ? - ?? ?????
?? ? ???? ??? ??
????? 1
????? 2
????? 3
?? ???? ? 0
lt4??????gt
lt8??????gt
? ?
??? ?? ???? ???? ??? ?? ?
81
DIP (Digital Image Processing) - Area Processing
2(Second-Order Differential operator)
Laplacian (?????) ?
????? ?? ???? ???? ?? ?? ??? ??? ????(??? ??) ??
???? ??? ???(zero -crossing) ??? ??
82
DIP (Digital Image Processing) - Area Processing
2(Second-Order Differential operator)
LoG (Laplacian of Gaussian)
Gaussian Smoothing? ??? ?, -gt ?????? ??
??
83
DIP (Digital Image Processing) - Area Processing
2(Second-Order Differential operator)
LoG (Laplacian of Gaussian) ?
84
DIP (Digital Image Processing) - Area Processing
2(Second-Order Differential operator)
DoG (Differential of Gaussian)
LoG? ?? ??? ???? ?? LoG? ????
? ???? ??? ???? ?? ??? ?? ?? ??? ???? ??? ??
??
??
85
DIP (Digital Image Processing) - Area Processing
2(Second-Order Differential operator)
DoG (Differential of Gaussian) ?
86
DIP (Digital Image Processing) - Area Processing
2(Second-Order Differential operator)
Canny ?? ???
LoG? ?? ??? ???? ?? LoG? ????
1) ?? ?? (good detection) 2) ?? ??? (good
localization) 3) ??? ??? ?? (response to a single
edge)
??
1. ???? ???? ??? ????. 2. ??? ?? ????? ??? ???
?? 3. ? ???? ??? ??? ?? 4. ? ??? ??? ??? ??? 2?
??? ??. 5. 2????? 0?? ??? ???. 6. 0? ?? ?? ??? ??
??? ??.
????
87
DIP (Digital Image Processing) - Area Processing
2(Second-Order Differential operator)
Canny?? ?
88
DIP (Digital Image Processing) - Area Processing
3(Color Edge Detection)
?? ?? ?? ??

1. HSI ????, ?? ??? ?? ??? I ? ?? ??, ??
2. RGB ???? ? ??? ??? ????? ??, ?? ??, ??? ??

??? ?? ? ?? ??
G(x,y) sqrt(edge_red(x,y)2
edge_green(x,y)2
edge_blue(x,y)2)/sqrt(3)
?? ??? ?? ???? ?? ???? ??? ?? ? ? ??
89
DIP (Digital Image Processing) - Area Processing
3(Color Edge Detection)
LoG ???? ??? ?? ??
90
DIP (Digital Image Processing) - Area Processing
3(Mean Filter)
?? ?? (Mean Filter)

1. ?? ?? ??? ?? ?? ?? ???? ????? ?? ?? ?? ???? ??
2. ??? ??? ???? ??? ??? ???

?? ??? ??
91
DIP (Digital Image Processing) - Area Processing
3(Mean Filter)
?? ?? (Mean Filter) ?
92
DIP (Digital Image Processing) - Area Processing
3(Separable Mean Filter)
?? ?? ?? (Separable Mean Filter)

1. ?????? ??
2. ??? ???.
3. ??? ??? ??? ??.
4. ???? ??? ??? ? ???? ??.

?? ??? ??
93
DIP (Digital Image Processing) - Area Processing
3(Median Filter)
??? ?? (Median Filter)

1. ??? ??? ????? ??
2. ???? ?? ?? ??? ??? ?? edge? ? ??

??? ??? ?? ??? ??
94
DIP (Digital Image Processing) - Area Processing
3(Median Filter)
??? ?? (Median Filter) ?
???? ??
????? ??? ????? ??
??? ??
??? ??? ??
95
DIP (Digital Image Processing) - Area Processing
3(Median Filter)
??? ?? (Median Filter) ? 2
96
DIP (Digital Image Processing) - Area Processing
3(Weighted Median Filter)
?? ??? ?? (Weighted Median Filter)

1. 1981? Justusson? ?? ??
2. ???? ??? ?? ???? ?? ??? ????? ????? ??? ??? ????
   ??
3. ?? ??? ??? ?? ??? ??? ??

?? ??? ??? ??
?, ??? ?? ??
97
DIP (Digital Image Processing) - Area Processing
3(Separable Median Filter)
?? ??? ?? (Separable Median Filter)

1. ??? ??? ??? ?? (?????? ??? ??)
2. ??? ??? ??
3. ??? ??
4. ???? ??? ??? ???? ??.

?? ??? ??
98
DIP (Digital Image Processing) - Area Processing
3(MIN /MAX Filter)
??? / ??? ??

• ???? ????? ???? ?? ???? ??? ??
• ?) ?????? ??
• ?? ??? ?? ???? ??? ????? ?? ???? ??

?? ??? ?? ??
??? ???
??? ??? ?? ??
??? ???
99
DIP (Digital Image Processing) - Area Processing
3(Expansion Contraction )
Expansion Contraction
??(Expansion)? ??(Contraction)? ?? ????? ?? ??
MIN ? MAX (Opening) ??? ??? ??? ? ????.
?? ? ??
MAX ? MIN (Closing) ??? ??? ??? ? ????.
?? ? ??
100
DIP (Digital Image Processing) - Area Processing
3(Ranked Order Filters )
Ranked Order Filters
??

• window? ??? ??? ???? ??? ??, rank? ???? ??? ????
  ???? ??

????

• ???? ??
• ??? ??? ? rank? ???? ???? ?? ?? ??
• if   rank0 then Mask0 -gt Min filter 
•       if   rankN/2 then MaskN/2 -gt Median
  filter 
•       if   rankN then MaskN -gt Max filter 

101
DIP (Digital Image Processing) - Area Processing
3(Ranked Order Filters )
Ranked Order Filters
102
DIP (Digital Image Processing) - Area Processing
3(trimmed mean filter)
trimmed mean filter

1. ??? ??? ?? ??? ??? ? ??
2. Trimmed Filters? ?? ??? ??? ??? ?? ???? ??? ???
   ???? Filtering
3. ???? ???? ???? ?????? ???? ??? ??? ???? ?? ????
   ??? ? ?? ???? ??

103
DIP (Digital Image Processing) - Area Processing
3(a-trimmed mean filter)
a-trimmed mean filter

• ??? ??? ?? ??? ??? ? ??
• a? 0?? 0.5?? ??
• a? 0.5?? ??? ???? ??, a? 0?? ?? ???? ??

?? ??

1. ????? 33 ??? ???.
2. ?????? ??
3. a? 0.5?? a 9 0.5 9 4.5? ?? ???? ?? 4? ??
   ?? 4?? ?? ??
4. ?? ?? ? ?? ?? ?? ??? ? (??? ??)

104
DIP (Digital Image Processing) - Area Processing
3(a-trimmed mean filter)
a-trimmed mean filter
105
DIP (Digital Image Processing) - Area Processing
3((r-s)-Fold trimmed mean filter)
(r-s) Fold trimmed mean filter
106
DIP (Digital Image Processing) - Area Processing
3(a Fold Winsorized mean filter)
a Fold Winsorized mean filter
107
DIP (Digital Image Processing) - Area Processing
3((r-s) Fold Winsorized mean filter)
(r-s) Fold Winsorized mean filter
108
DIP (Digital Image Processing) - Area Processing
3(Modified Trimmed Mean Filter)
Modified Trimmed Mean Filter

1. window? ??? ???? ????.
2. Median?? ???.
3. ??? q ?(???? ??? ??? ??)? ???.
4. ???? ? ?? ?? ?? ????, q? ?? ?? ?? ??

109
DIP (Digital Image Processing) - Area Processing
3(K-Nearest Neighbor Filter )
 K-Nearest Neighbor Filter
??

• ???(central)? ???? ?? ??? ????, ???? K??? ??? ???
  ??
• K? ???  (1KN)??.

????

1. Center?? ???.
2. ???(K?)? ???. (1KN)
3. ???? ?? ??? ???? K? ?? ?? ??? ???

110
DIP (Digital Image Processing) - Area Processing
3(K-Nearest Neighbor Filter )
 K-Nearest Neighbor Filter
111
DIP (Digital Image Processing) - Area Processing
3(Modified K-Nearest Neighbor Filter )
Modified K-Nearest Neighbor Filter
??

• ???(central)? ???? ?? ? ???? ??? ?? ?? ??? q? ??
  ?? ?? ??? ??
• ?? q? ?? Noise ???? s??, Sigma filters

????

1. Center?? ???.
2. ???(q?)? ???.
3. ???? ?? ??? ???? K? ?? ?? ??? ???

112
DIP (Digital Image Processing) - Area Processing
3(Modified K-Nearest Neighbor Filter )
Modified K-Nearest Neighbor Filter
113
DIP (Digital Image Processing) - Area Processing
4(Adaptive Median Filter )
Adaptive Median Filter
??

• ??? ????? ?? ? ??? ???? ??? ??? ????, ? ?? ??
  ????, ? ??? ??

????

• ?? ?? ??
• if ?? ?? ???? Median Filter
•      else ? ??

????
1. ???? ?? ??? ???? 2. ??? ?? ???? 3. ??? ?? ??
114
DIP (Digital Image Processing) - Area Processing
4(Adaptive Median Filter )
Adaptive Median Filter
115
DIP (Digital Image Processing) - Area Processing
4(d-Adaptive Median Filter )
d-Adaptive Median Filter
??
????, ????? ?? ???? ?? ?? ?(d)? ??? ?
????? ?? ??? ????? ???? Median Filter?
?? ?? ?? ?? ??? ? ??? ???? ?? ??? ????
???? ??
????

• ???? ???
• if abs(??? - ?? ?) lt d ?? ? ??
•      else Median Filter

116
DIP (Digital Image Processing) - Area Processing
4(d-Adaptive Median Filter )
d-Adaptive Median Filter
117
DIP (Digital Image Processing) - Area Processing
4(q-Adaptive Median Filter )
q-Adaptive Median Filter
??
?? ????? ??? ???(q)? ??? ??? ???? ?? ?
Median Filters? ???? ?? ??? ??? ??? ?? ? ?
??? ???? ??
????

• ?????? ?? ???
• if ?????? gt q ?? Median Filter
•     else ? ??

?????? ???(?????)? central ?? ?? ????
118
DIP (Digital Image Processing) - Area Processing
4(q-Adaptive Median Filter )
q-Adaptive Median Filter
119
DIP (Digital Image Processing) - Area Processing
4(k-Adaptive Median Filter )
k-Adaptive Median Filter

1. q-Adaptive Median Filters? ??? ??? ??
2. ??? ??? ?? ??? ??
3. ?? ?????? ???? ??? ?? ? ?? ??? ?? ?? ? ?? ??

??
?? ????? ??? 3? ?? k? ??? ?? ?? ? ??(???
????)?? ??? ? ??? ?? ??? ?? ?? ? ?? ???? ????
???? ?? ? Median Filters ?? k ?? ?? ??? ???
???? ??? ????? ? ?? ?? ?? Midian Filter? ???? ???
????.
120
DIP (Digital Image Processing) - Area Processing
4(k-Adaptive Median Filter )
k-Adaptive Median Filter
????

• ?????? ??? ???
• if ?? ???? ?? ? ? ?? k? ?? ?? ? ??
•     else Median Filter

121
DIP (Digital Image Processing) - Area Processing
4(k-Adaptive Median Filter )
k-Adaptive Median Filter
122
DIP (Digital Image Processing) - Area Processing
4(a-Adaptive Median Filter )
a-Adaptive Median Filter

1. ?? ??? ????? ?? ? ????? ?? ???? ??? ???? ???? ??
2. ????? ??? ??? ???? ???? ?????? ?? ????? ?? ?????
   ??? ?? ??? ?????.

??
????
?? ????? a? ? ?????? ?? ?? ? Median Filter?
?? ??? ? ? ??? ??
1. ????? ?? ????? ??? 2. if?? ???? gt
(1 a x ????) ??              ??? ?
??? ? ?? ?
123
DIP (Digital Image Processing) - Area Processing
4(a-Adaptive Median Filter )
a-Adaptive Median Filter
124
DIP (Digital Image Processing) - Topological
Processing
??? ??(Topological processing)
??? ??? ???? ??? ??? ???? ??? ???? ?
(?) ???(scale ?? ??? ?) ??(Rotation)
??(Translation) ?? ?
?? ??
125
DIP (Digital Image Processing) - Topological
Processing(??)
??(Transformation, Matching, Imaging)
??? ? ?? ??(Source image)? ??? ?? ?? (Target
image)? ??? ???? ?? ??? ???? ??? ?
??? ?? ? ??? ??
x, y? ??? ?? ?? ??? ?? ??? ?? ?? ?
??? ??

1. ?? ??? ???? ? ?? ???? ??? ?? ???? ???? ?? ???
   ???? ??? ??? ? ?? ??
2. ??? ??? ???? ?? ???? ??

??? ??
126
DIP (Digital Image Processing) - Topological
Processing(??)
??? ??? ???
? ??? (overlap)
2?? ?? ??? ?? ?? ??? ?????
? ? (hole)
????? ???? ??, ?? ???? ?? ??? ?? ??
127
DIP (Digital Image Processing) - Topological
Processing(??)
??? ??
????? ??? ?? ??? ???? ?? ?? ???? ?? ??? ?? ?? ???
? ?? ??
128
DIP (Digital Image Processing) - Topological
Processing(Interpolation)
??? (Interpolation)? ??

• ??? ??? ?? ?? ??? ????? ??? ??? ?? ???? ???? ??
• ??? ????? ?? ??? ????? ??? ?? ????? ?? ??
  ??(Running Time)? ??

??? 2? ???? ??
???
x source ( x dest ) / 2 y source ( y dest ) /
2
? Nearest Neighbor interpolation ? Bilinear
interpolation ? Cubic Convolution
interpolation ? B-Spline interpolation
129
DIP (Digital Image Processing) - Topological
Processing(Interpolation)
Nearest Neighbor Interpolation

• ?? ??? ??? ??? ?? ??? ?? ??? ?? ??? ???? ??
• ????? ???? ??, ??? ??? ?? ??? ??? ??? ??
• ??? ???? ???? ??? ??? ?????? ??? ??? ? ?? ??? ???
  ??
• ??? ?? ??? ???? ?? ???? ?? ?? ??? ??? ?? ??

?? ??? ?? ?? ???
130
DIP (Digital Image Processing) - Topological
Processing(Interpolation)
Bilinear Interpolation

• ??? ??? ??? ?? ? ?? ?? ??? ???? ???? ?? ?? ?
• ???? ????? ??????, ?? ???? ??? ???? ?????? ??? ???

131
DIP (Digital Image Processing) - Topological
Processing(Interpolation)
Bilinear Interpolation ??

• ?? ??? ???? ????? ? ???? ??? ??
• 3?? ??? ?? ?????? ???? ??? ?? ?? ????? ??? ??? ??
  ??? ??

??? ???
132
DIP (Digital Image Processing) - Topological
Processing(Interpolation)
?? Interpolation
3? ?? ???

• cubic interpolation
• 44 ? ????? ???? ???? ??
• ??? ????? ??? ? ???? ????? ? ??

B-???? ???

• ???? ????? ??? ??????, B-???? ??? ??? ?? ???
  ??????.
• ?? ???? ?? ?????? ??