HỌC VIỆN CÔNG NGHỆ BƯU CHÍNH VIỄN THÔNG

NGUYỄN VĂN HẠT
NGHIÊN CỨU MỘT SỐ KỸ THUẬT NỘI SUY ẢNH

Chuyên ngành: Truyền dữ liệu và Mạng máy tính
Mã số: 60.48.15

Người hướng dẫn khoa học: PGS. TS ĐỖ NĂNG TOÀN TÓM TẮT LUẬN VĂN THẠC SĨ KỸ THUẬT

HÀ NỘI – 2012 1
PHẦN MỞ ĐẦU
             

 1: 
 

 


 



3
CHƢƠNG 1: KHI QUT VỀ X L NH V NI SUY NH



















:




























. .






 , 





, . 






























4



 
Hình 1.3 Ví dụ về nắn chỉnh hình biến dạng

 

1.2.5 Các kiểu ảnh
a. Ảnh chỉ số



b. Ảnh cường độ


c. Ảnh nhi phân


d. Ảnh RGB
 


6
1.2.6 Quan hệ giữa các điểm ảnh






1.3.2 Các vấn đề với nội suy ảnh




.
1.3.2.1 
     

1.3.2.2 





1.3.2.3 




1.3.2.4 



8

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9
CHƢƠNG 2: MT SỐ KỸ THUẬT NI SUY NH













p







     
cao   ban .   chung,
       cao  .
      
        
   nhi    ).
Trong  l       cong,
      
     .
P    4
  trong      

11
thu     , 
  .      
s  xung quanh   .
2.1.2.2 N   hai
     
pixel i, j)     (,
2j)       
.   
Bước 1    
2.1.A)   trung  
Bước 2:      2.1.B)
 ,  trung  
 4 ).

Hình 2.1 Hai bƣớc nội suy dựa vào cấu hình của bốn nƣớc lng giềng
        
      

13
2.1.2.4  ICBI
     
  cho    
   (2i + 1; 2j + 1).
Sau khi   hai   (   
),      , 
       
 o.
2.1.2.5  NN(Natural Neighbor Interpolation)
 m (DEM)      
.  NNI (Natural Neighbor
Interpolation)   DEM  
   . M (DEM)  
   qua DEM . K  
 , (  .
a. Sơ đồ Voronoi của nội suy láng giềng tự nhiên
 
Ta ,
v 
2
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p
n

 Vor
S
 S.
b. Phương pháp nội suy láng giềng tự nhiên

 DEM       cho 
. Q     l .  
 DEM,  ta  xem   
. N NO_DATA". Thay  
     ,  
,   trong   .
Kết luận nội suy láng riềng tự nhiên
     , 
      
    p       
   , 
        
 (2i, 2j)       (2i +1, 2j+1) 
FCBI    cho  khi     
       
  FCBI p   4  
 .      to .

15
  DEM , h  bao  
   ,   NNI 
 NNI DEM .
2.2 Nội suy tuyến tính (Linear interpolation)
  
 
      
 
. 



[k]
) y
[k]
1 (1,1) 2
2 (2,3) 2
3 (2,5) 5
4 (4,2) 1
5 (5,5) 6
5    .
   R
2


1
,x
2

6
x
1
x
2

5
x
2
1

4
x


c
 

2.3 Nội suy s dụng hàm cơ sở bn kính
RBF      
d   p  c.     tham
        . 
 RBF   t  ,  cho 
RBF  .

17
2.3.1 Khái quát về hàm cơ sở bán kính RBF
    
 ta      
 t.

s
 R      
  R 

)()( rX


(2.47)

xr 

V  R
s,

         



N
k
kkf
xxCxP
1
2
)(

, x  R
S
(2.60)
18
   p

(x
i
) = f(x
i
), i= 1, . . ., N, 
 c


















)x(f
)x(f
)x(f
C
C
C
xxxxxx
xxxxxx
xxxxxx
N
2
1
N


.
Kết luận nội suy sử dụng hàm cơ sở bán kính RBF
 






19
CHƢƠNG 3: CHƢƠNG TRÌNH TH NGHIỆM
3.1 Bài ton








 Đầu vào 

 Đầu ra

3.2 Phân tích bài ton

 

 

:

Hình 3.4 Trạng thi mỉm cƣời của khuôn mặt

              
,l   


22




 
.