From: Yu Lianqing <yulianqing74@ne...>  20021028 01:06:08

PMatrixDecompCR(oxl/mvl) decomposes a projection matrix P into the form P = K [R t] where K is upper triangular and R is a rotation. However, it only guarantees that K(0,0)>0 and K(2,2)=1 and not K(1,1)>0, which should be the focal length in y coordinate axis. For example, for a projection matrix: 12.80 0.70 0.87 0.45 0.67 12.82 0.49 0.89 0.00 0.00 0.04 0.00 we get: calibration: 299.998282844 0.000019245 0.000050939 0.000000000 300.001236810 0.003046630 0.000000000 0.000000000 1.000000000 rotation: 0.996196941 0.054735483 0.067791459 0.052208744 0.997893760 0.038500522 0.069756019 0.034814795 0.996956382 translation: 0.034816940 0.069632838 0.034816739 if we set t=[1 0 0; 0 1 0; 0 0 1], right multiply C with t and left multiply R with inv(t), the correct result can be obtained calibration: 299.998282844 0.000019245 0.000050939 0.000000000 300.001236810 0.003046630 0.000000000 0.000000000 1.000000000 rotation: 0.996196941 0.054735483 0.067791459 0.052208744 0.997893760 0.038500522 0.069756019 0.034814795 0.996956382 translation: 0.034816940 0.069632838 0.034816739 Are there anyone notice this issue, what is your opinions? help and discussion appreciated!  Your favorite stores, helpful shopping tools and great gift ideas. Experience the convenience of buying online with Shop@...! http://shopnow.netscape.com/ 