RECTIFYHOMOG Apply rectifying homographies to an image set
Usage: figure(101); % Initial figure for rectiied image display
rectifyhomog(ims,roc,k0,'ga'); % plot in individual figures
Inputs:
ims{nc} cell array of input images (colour or monochrome)
roc(3,3,nc) rotation matrices from world coordinates to camera coordinates
k0 camera matrix or focal length in pixels optionally divided by the image width [0.8]
mode mode string
g show images on separate figures
G tile images onto a single figure [default if no output arguments]
k clip to original image dimensions
l do not link axes
v k0 contains diffent values for each camera
a orient to average camera orientation
[z make optical axis perpendicular to camera plane]
[x align x axis with camera displacements]
Outputs:
imr{nc}(my,mx,nc) output images (uint8)
xa{nc}(mx) x axis for each image
ya{nc}(my) y axis for each image0001 function [imr,xa,ya]=rectifyhomog(ims,roc,k0,mode) 0002 %RECTIFYHOMOG Apply rectifying homographies to an image set 0003 % 0004 % Usage: figure(101); % Initial figure for rectiied image display 0005 % rectifyhomog(ims,roc,k0,'ga'); % plot in individual figures 0006 % 0007 % Inputs: 0008 % ims{nc} cell array of input images (colour or monochrome) 0009 % roc(3,3,nc) rotation matrices from world coordinates to camera coordinates 0010 % k0 camera matrix or focal length in pixels optionally divided by the image width [0.8] 0011 % mode mode string 0012 % g show images on separate figures 0013 % G tile images onto a single figure [default if no output arguments] 0014 % k clip to original image dimensions 0015 % l do not link axes 0016 % v k0 contains diffent values for each camera 0017 % a orient to average camera orientation 0018 % [z make optical axis perpendicular to camera plane] 0019 % [x align x axis with camera displacements] 0020 % Outputs: 0021 % imr{nc}(my,mx,nc) output images (uint8) 0022 % xa{nc}(mx) x axis for each image 0023 % ya{nc}(my) y axis for each image 0024 0025 % Copyright (C) Mike Brookes 2012 0026 % Version: $Id: rectifyhomog.m 1642 2012-03-16 16:22:26Z dmb $ 0027 % 0028 % VOICEBOX is a MATLAB toolbox for speech processing. 0029 % Home page: http://www.ee.ic.ac.uk/hp/staff/dmb/voicebox/voicebox.html 0030 % 0031 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 0032 % This program is free software; you can redistribute it and/or modify 0033 % it under the terms of the GNU General Public License as published by 0034 % the Free Software Foundation; either version 2 of the License, or 0035 % (at your option) any later version. 0036 % 0037 % This program is distributed in the hope that it will be useful, 0038 % but WITHOUT ANY WARRANTY; without even the implied warranty of 0039 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 0040 % GNU General Public License for more details. 0041 % 0042 % You can obtain a copy of the GNU General Public License from 0043 % http://www.gnu.org/copyleft/gpl.html or by writing to 0044 % Free Software Foundation, Inc.,675 Mass Ave, Cambridge, MA 02139, USA. 0045 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 0046 if ~iscell(ims) 0047 ims={ims}; 0048 end 0049 nc=numel(ims); % number of images 0050 if ~((nc==1 && isequal(size(roc),[3 3])) || isequal(size(roc),[3 3 nc])) 0051 error('roc should have dimensions [3,3,%d]',nc); 0052 end 0053 if nargin<4 || ~numel(mode) 0054 mode=''; 0055 end 0056 if nargin<3 || ~numel(k0) 0057 k0=0.8; 0058 end 0059 if nargin<2 || ~numel(roc) 0060 roc=repmat(eye(3),[1 1 nc]); 0061 end 0062 0063 % sort out options 0064 0065 vv=any(mode=='v'); % different k0 for each camera 0066 nk=numel(k0)/(1+vv*(nc-1)); % number of k parameters per camera 0067 switch nk 0068 case {1,3} 0069 k0=reshape(k0,[1 nk 1+vv*(nc-1)]); 0070 case 9 0071 k0=reshape(k0,[3 3 1+vv*(nc-1)]); 0072 otherwise 0073 error('k0 must have 1, 3 or 9 values per camera'); 0074 end 0075 ncr=1+(nargout>0)*(nc-1); % numer of output images 0076 if any(mode=='g') 0077 gmode=1; 0078 elseif any(mode=='G') || ~nargout 0079 gmode=2; 0080 else 0081 gmode=0; 0082 end 0083 if gmode>0 0084 fig0=gcf; % initialize the figure 0085 end 0086 if any(mode=='k') 0087 modeh='kxt'; 0088 else 0089 modeh='t'; 0090 end 0091 0092 % determine a global camera rotation 0093 0094 if any(mode=='a') 0095 qrc=zeros(4,nc); % calculate the mean camera orientation 0096 for i=1:nc 0097 qrc(:,i)=rotro2qr(roc(:,:,i)); 0098 end 0099 rocmean=rotqr2ro(rotqrmean(qrc)); 0100 else 0101 rocmean=eye(3); 0102 end 0103 0104 % now do image transformations 0105 0106 imr=cell(ncr,1); 0107 xa=imr; 0108 ya=imr; 0109 axh=zeros(nc,1); 0110 splx=ceil(sqrt(nc)); 0111 sply=ceil(nc/splx); 0112 for i=1:nc 0113 k0i=k0(:,:,1+vv*(i-1)); % camera parameters 0114 if numel(k0i)<9 0115 imsz=size(ims{i}); 0116 fe=k0(1); 0117 if fe<0.1*imsz(2) % focal length is a fraction of the width 0118 fe=k0*imsz(2); 0119 end 0120 if numel(k0i)<3 0121 xy0=(imsz(2:-1:1)+1)/2; 0122 else 0123 xy0=k0i(2:3); 0124 end 0125 k0=eye(3); 0126 k0(1:4:5)=fe; 0127 k0(7:8)=xy0; 0128 end 0129 j=min(i,ncr); 0130 rocall=rocmean*roc(:,:,i)'; 0131 titl=sprintf('%d: pan-tilt-roll = %.1f°, %.1f°, %.1f°',i,-rotro2eu('yxz',rocall)*180/pi); 0132 [imr{j},xa{j},ya{j}]=imagehomog(uint8(ims{i}),k0*rocall/k0,modeh); % apply inverse of rotation matrix 0133 if gmode>0 0134 if gmode>1 0135 subplot(sply,splx,i); 0136 else 0137 figure(fig0+i-1); 0138 end 0139 imagesc(xa{j},ya{j},imr{j}); 0140 axis image 0141 title(titl); 0142 axh(i)=gca; 0143 end 0144 end 0145 if gmode>0 && nc>1 0146 if ~any(mode=='l') 0147 linkaxes(axh); 0148 end 0149 figure(fig0); 0150 end