Matlab内图片的拉伸

piday123

Matlab里面显示一张图片的话，长宽比取决于图片的横向纵向像素点数。
如果一张图片是433×433的话，那么imshow之后，就会按1比1比例显示，即使你拉伸窗口。
# d! m" Q8 {5 V
, k6 u" k% K/ j1 k$ v+ i5 d6 rfname = 'frog.bmp';
! y# C$ M2 ?' t! D1 lA=imread(fname);
; V6 M; e' [, aimshow(A);
0 f) D& ^, G, e4 p5 T- Aset(gcf,'position',[100 100 400 800]);
  O% W5 }6 E  z+ Q效果如下:

' T: E. O+ r1 f
; D; w& Z) F& X7 b
1 m' v# G1 D. v怎么能让图片充满整个画框呢。可以用画图板打开，拉伸图片，然后重新保存。
: \, }* {9 d0 F5 Q4 Z( D8 }或者写个函数
& C* |* \& I$ [7 ~4 Q
B= figure_stretch(A,1,3);
4 n- X, B, C: ~' M1 y5 F' Gfigure
imshow(B);
set(gcf,'position',[100 100 400 800]);
* S: V+ _- B* c6 ]! `. U
+ f% B" N/ ?/ [8 a效果如下:

" g0 F8 E- W  `

figure_stretch函数如下：
+ P( x3 Z( n2 jfunction C=figure_stretch(fname,w_scale,h_scale)
% Stretch the figure.
% Usage:
# J7 x( }, L9 a) H% C=figure_stretch(fname,w_scale,h_scale)
+ B0 q  F/ t) Z+ i- {% fname        : name of the figure
3 {6 \" b" n; E" S& g6 J% w_scale      : stretch scale in width
/ L, e9 O* `, Q: H% h_scale      : stretch scale in hight
% Example:
% fname = 'frog.bmp';
- R( ?" k8 C  p8 d) H9 R% L% B= B= figure_stretch(fname,1,3);
% figure
8 B/ |8 E6 g9 H0 P$ x# d. K% {% ]% imshow(B);
% Author :  Haiyang Cui
% EMail  :  ***

) {# `# k' w; D$ s/ bA= imread(fname);
[I,J,K]=size(A);
x0=1:J;
y0=1:I;
3 W7 c. E- W/ z4 b[X0,Y0] = meshgrid(x0,y0);
4 }  x; o, E4 ?. R, l7 z" RI1 = floor(I*h_scale);
J1 = floor(J*w_scale);

R = A(:,:,1);
G = A(:,:,2);
B = A(:,:,3);

%
x = 1:J1;
y = 1:I1;
[X,Y] = meshgrid(x,y);
3 [, Q' q5 L' J) z( G( T+ ?7 O
X = X*J/J1;
Y = Y*I/I1;
- ], W0 R( l8 a8 s3 pX = double(X);
5 ]& r! \, P3 t4 \1 hY = double(Y);
R = double(R);
G = double(G);
B = double(B);
6 |( V+ ]5 l+ v0 V/ r%
R1 = interp2(X0,Y0,R,X,Y);
3 _! U$ Z) k4 w; TG1 = interp2(X0,Y0,G,X,Y);
6 u: {" @: S! `" b# ]) ~B1 = interp2(X0,Y0,B,X,Y);
C(:,:,1)=uint8(R1);
C(:,:,2)=uint8(G1);
C(:,:,3)=uint8(B1);
* l3 P# p' N& [( |; Y' nend

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Matlab内图片的拉伸