OpenCV perspective transform in python

Question

I\'m trying to rectify an image in python. I have a Homography H (from a rotation matrix that rotates around the x, y and z axis) that looks like this for example: [

Answer 1

It says the image should be np.float32 or np.float64.

So convert the image first by img_cv2 = np.float32(img_cv2).

Then apply the cv2.perspectiveTransform() and cv2.warpPerspective()

Check this tutorial for demo

Answer 2

I think what you want is cv2.warpPerspective (see documentation (link)), not cv2.perspectiveTransform.

Answer 3

The source and destination image must be floating point data.

cv2.perspectiveTransform(src, m[, dst]) → dst

Parameters:

• src – input two-channel or three-channel floating-point array; each element is a 2D/3D vector to be transformed.
• dst – output array of the same size and type as src.
• m – 3x3 or 4x4 floating-point transformation matrix.

Refer:http://docs.opencv.org/modules/core/doc/operations_on_arrays.html?highlight=perspectivetransform#cv2.perspectiveTransform

So convert the 8U image to the appropriate datatype.