Homework4 – SfM
Just to let you get initial experience on SfM
1.In this homework, you have to work on not only the given
data but your own photos.
2.You are allowed to use any camera calibration related
functions.
Steps
1. find out correspondence across images
and the corresponding epipolar lines in another
2. estimate the fundamental matrix across images (normalized 8 points)
3. draw the interest points on you found in step.1 in one image
two images
know intrinsic matrix
, 1.4219 0.0005 0.5092
K = , 0 1.4219 0 0
0.3802 0.0010
Homework4 – SfM
Just to let you get initial experience on SfM
two images
know intrinsic matrix
1.4219 0.0005 0.5092
K = 0 1.4219 0 0
Steps
1. find out correspondence across images
2. estimate the fundamental matrix across images (normalized 8 points) 3. draw the interest points on you found in step.1 in one image
and the corresponding epipolar lines in another
0.3802 0.0010
Homework4 – SfM
Just to let you get initial experience on SfM
two images
know intrinsic matrix
1.4219 0.0005 0.5092 K = 0 1.4219 0.3802 0 0 0.0010
Steps
1. find out correspondence across images
2. estimate the fundamental matrix across images (normalized 8 points) 3. draw the interest points on you found in step.1 in one image
and the corresponding epipolar lines in another
4. get 4 possible solutions of essential matrix from fundamental matrix, hint:
[U,S,V] = svd(E);
m = (S(1,1)+S(2,2))/2;
E = U*[m,0,0;0,m,0;0,0,0]*V’;
[U,S,V] = svd(E);
W = [0,-1,0;1,0,0;0,0,1];
Homework4 – SfM
Just to let you get initial experience on SfM
two images
know intrinsic matrix
1.4219 0.0005 0.5092
K = 0 1.4219 0 0
Steps
1. find out correspondence across images
2. estimate the fundamental matrix across images (normalized 8 points) 3. draw the interest points on you found in step.1 in one image
and the corresponding epipolar lines in another
4. get 4 possible solutions of essential matrix from fundamental matrix 5. find out the most appropriate solution of essential matrix
6. apply triangulation to get 3D points
0.3802 0.0010
Homework4 – SfM
Just to let you get initial experience on SfM
two images
know intrinsic matrix
1.4219 0.0005 0.5092
K = 0 1.4219 0 0
Steps
1. find out correspondence across images
2. estimate the fundamental matrix across images (normalized 8 points) 3. draw the interest points on you found in step.1 in one image
and the corresponding epipolar lines in another
4. get 4 possible solutions of essential matrix from fundamental matrix 5. find out the most appropriate solution of essential matrix
6. apply triangulation to get 3D points
7. use texture mapping to get a 3D model (matlab code will be provided)
0.3802 0.0010
obj_main(3dPoints, 2dPoints, CameraMatrix, ’Mesona1.JPG’, 1);
K I| 0
Homework4 – SfM
Just to let you get initial experience on SfM
two images
know intrinsic matrix
know extrinsic matrix (extrinsic for your reference)
P KR,RT
Homework4 – SfM
3 ‣For your own photos:
– Take your own photos
– Do calibration on your photos
Just to let you get initial experience on SfM
0.5092 0.3802 0.0010
‣For the given data:
– Follow instructions in slide 2 to 6 to reconstruct 3D model. – Camera parameters are provided in Statue_calib.txt
Steps
1. find out correspondence across images
– Reconstruct 3D model
2. estimate the fundamental matrix across images (normalized 8 points) 3. draw the interest points on you found in step.1 in one image
and the corresponding epipolar lines in another
two images
know intrinsic matrix
K = ,
0 1.4219 0 0
, 1.4219 0.0005
