V_RECTIFYHOMOG Apply rectifying homographies to an image set
Usage: figure(101); % Initial figure for rectiied image display
v_rectifyhomog(ims,roc,k0,'ga'); % plot in individual figures
Inputs:
ims{nc} cell array of input images (colour or monochrome)
roc(3,3,nc) v_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]=v_rectifyhomog(ims,roc,k0,mode) 0002 %V_RECTIFYHOMOG Apply rectifying homographies to an image set 0003 % 0004 % Usage: figure(101); % Initial figure for rectiied image display 0005 % v_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) v_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: v_rectifyhomog.m 10865 2018-09-21 17:22:45Z 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 v_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)=v_rotro2qr(roc(:,:,i)); 0098 end 0099 rocmean=v_rotqr2ro(v_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,-v_rotro2eu('yxz',rocall)*180/pi); 0132 [imr{j},xa{j},ya{j}]=v_imagehomog(uint8(ims{i}),k0*rocall/k0,modeh); % apply inverse of v_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