OpenCV 2.4 estimateAffine3D in Python

numpy, opencv, python-2.7

Solution

This is a known bug that is fixed in `2.4.4`.

http://code.opencv.org/issues/2375

If you just need rigid (rotation + translation) alignment, here's the standard method:

def get_rigid(src, dst): # Assumes both or Nx3 matrices
    src_mean = src.mean(0)
    dst_mean = dst.mean(0)
    # Compute covariance 
    H = reduce(lambda s, (a,b) : s + np.outer(a, b), zip(src - src_mean, dst - dst_mean), np.zeros((3,3)))
    u, s, v = np.linalg.svd(H)
    R = v.T.dot(u.T) # Rotation
    T = - R.dot(src_mean) + dst_mean # Translation
    return np.hstack((R, T[:, np.newaxis]))

Problem

I'm trying to use the method cv2.estimateAffine3D but without success. Here is my code sample : ``` import numpy as np import cv2 shape = (1, 4, 3) source = np.zeros(shape, np.float32) # [x, y, z] source[0][0] = [857, 120, 854] source[0][1] = [254, 120, 855] source[0][2] = [256, 120, 255] source[0][3] = [858, 120, 255] target = source * 10 retval, M, inliers = cv2.estimateAffine3D(source, target) ``` When I try to run this sample, I obtain the same error as this other post here. I'm using OpenCV 2.4.3 and Python 2.7.3 Please help me!

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