source: liacs/la/opdr3/rotate.m@ 404

Last change on this file since 404 was 2, checked in by Rick van der Zwet, 15 years ago

Initial import of data of old repository ('data') worth keeping (e.g. tracking
means of URL access statistics)

File size: 1.2 KB
Line 
1function B = rotate(A,degrees)
2 % With a litle help of
3 % http://www.mathworks.com/matlabcentral/
4 % fileexchange/loadFile.do?objectId=4071
5 %
6 % bepaal dimentie
7 B = A;
8 degrees_rad = degrees * pi / 180;
9 %rotatiematrix
10 R = [ cos(degrees_rad), sin(degrees_rad), 0;
11 sin(-degrees_rad), cos(degrees_rad), 0;
12 0, 0, 1];
13 %bepaal buitenzijden en midden
14 [in_size_x, in_size_y] = size(A);
15 in_mid_x = ( in_size_x-1) / 2;
16 in_mid_y = ( in_size_y-1) / 2;
17 %max grootte van het nieuwe plaatje is de helft de diameter
18 % en dan 'rechtop'
19 dia = int64(sqrt(in_size_x^2 + in_size_y^2 ));
20 B = zeros([dia,dia]);
21 %grootte van de nieuwe matrix
22 [out_size_x, out_size_y] = size(B);
23 out_mid_x = ( out_size_x-1) / 2;
24 out_mid_y = ( out_size_y-1) / 2;
25 %
26 %translatiematrix
27 Tout = [ 1, 0, out_mid_x;
28 0, 1, out_mid_y;
29 0, 0, 1;];
30 Tin = [ 1, 0, -in_mid_x;
31 0, 1, -in_mid_y;
32 0, 0, 1; ];
33 Trans = Tout * R * Tin;
34 % Laten we maar gaan draaien ;-)
35 for i=1:in_size_x
36 for j=1:in_size_y
37 out = round(Trans * [i;j;1;]);
38 %gegevens overhevelen
39 B(out(1),out(2)) = A(i,j);
40 end
41 end
42
43
44
Note: See TracBrowser for help on using the repository browser.