I want to apply a affine transformation on a image. I know some (at least 3) points on the current image and the same points on the "new image" (after the affine transformation).
I can not use the function from matlab or opencv to perform the geometric operation and only find basic operation like rotation or translation in the vision module
You should look at the calibration functions. An affine transform is a subset of the perspective transform that the calibration functions provide.
Thanks for your answer.
I actually manage to implement in labview the transformation affine and the estimation of its matrix, once I really understand the bilinear interpolation
Sometimes it is easier to work with image in the form of 2D array (especially if you are working with grayscale image).
In that case Functions>>Mathematics>>Geometry pallet should be exactly what you need.
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Do you have a VI fo the affine tranformation? for 3 points?
Maybe kl3m3n posted something you're looking forward: https://decibel.ni.com/content/blogs/kl3m3n/2015/04/24/homography-mapping-calculation-labview-code
write the equation for affine transformation and solve it. You need 3 point pairs for this. If you have more points, you could use a least-squares approach.
If you don't like coding, you can use OpenCV's functions getAffineTransform() and estimateRigidTransform(), respectively. Just perform a .dll call - there are a lot of examples online.
to help you a bit further, here is an example of calculating the affine transformation (least square), provided you know the three corresponding point pairs.
Hope this helps.