Translation Matrix For Image Processing Confusion

Hi,

Im quite confuse with the matrix translation use to translate image in 3D using homogenous coordinate. In Matlab the coordinat for tx and tx is at the bottom left

whereas there are a lot of example in the internet is at on the right corner and given with a very simple example from 2D conversion as in the image.

What is the difference or is it very similar?

Thanks

Zamani

Answer 1

[Prabhan Purwar]

Hi,

These two representations of Translational Transformation are pretty the same and just vary in the way matrix multiplication takes place.

%MATLAB METHOD
>> [x y 1]*[1 0 0;0 1 0;tx ty 1]
 
ans =
 
[tx + x, ty + y, 1]

%OTHER METHOD
>> [1 0 tx;0 1 ty;0 0 1]*[x;y;1]
 
ans =
 
tx + x
ty + y
     1
     

Thanks