Calculating the transform matrix

  • Thread starter cnix
  • Start date
  • #1
1
0
I have 2 sets of known 3x1 vectors A = [ x y 1 ] and B =[ x' y' 1 ] which represent points on two coordinates calculated by some MATLAB algorithm. I was wondering what I could do to find the 2x3 transform matrix that turns the x y set into the x' y' set.

[x'] [ ] [x]
[y']=[?] [y]
[1] [1]

B = QA

Q = 2x3 unknown transform matrix

What I've tried:
multiplying both sides by A-1, and im left with A-1*B which is just a 1x1 scalar value. I've tried multiplying the variables out and I'm left with 2 equations and 6 unknowns. I also have many different values of xy & x'y' pairs given by the matlab algorithm but I dont see how that could help me. Any help is appreciated.
 

Answers and Replies

  • #2
Erland
Science Advisor
738
136
The system QA has two equations and six unknowns, the elements of Q. We can solve the system for these unknowns, which gives a solution with four parameters.
 

Related Threads on Calculating the transform matrix

  • Last Post
Replies
8
Views
2K
  • Last Post
Replies
2
Views
3K
Replies
2
Views
2K
  • Last Post
Replies
8
Views
3K
  • Last Post
Replies
8
Views
911
Replies
1
Views
2K
  • Last Post
Replies
3
Views
7K
Replies
5
Views
16K
Replies
4
Views
94
Top