opencv/samples/python2/common.py
2011-06-14 15:02:57 +00:00

73 lines
1.6 KiB
Python

import numpy as np
import cv2
def to_list(a):
return [tuple(p) for p in a]
def anorm2(a):
return (a*a).sum(-1)
def anorm(a):
return np.sqrt( anorm2(a) )
def homotrans(H, x, y):
xs = H[0, 0]*x + H[0, 1]*y + H[0, 2]
ys = H[1, 0]*x + H[1, 1]*y + H[1, 2]
s = H[2, 0]*x + H[2, 1]*y + H[2, 2]
return xs/s, ys/s
def to_rect(a):
a = np.ravel(a)
if len(a) == 2:
a = (0, 0, a[0], a[1])
return np.array(a, np.float64).reshape(2, 2)
def rect2rect_mtx(src, dst):
src, dst = to_rect(src), to_rect(dst)
cx, cy = (dst[1] - dst[0]) / (src[1] - src[0])
tx, ty = dst[0] - src[0] * (cx, cy)
M = np.float64([[ cx, 0, tx],
[ 0, cy, ty],
[ 0, 0, 1]])
return M
def lookat(eye, target, up = (0, 0, 1)):
fwd = np.asarray(target, np.float64) - eye
fwd /= anorm(fwd)
right = np.cross(fwd, up)
right /= anorm(right)
down = np.cross(fwd, right)
Rt = np.zeros((3, 4))
Rt[:,:3] = [right, down, fwd]
Rt[:,3] = -np.dot(Rt[:,:3], eye)
return Rt
def mtx2rvec(R):
pass
if __name__ == '__main__':
import cv2
from time import clock
'''
w, h = 640, 480
while True:
img = np.zeros((h, w, 3), np.uint8)
t = clock()
eye = [5*cos(t), 5*sin(t), 3]
Rt = lookat(eye, [0, 0, 0])
'''
eye = [1, -4, 3]
target = [0, 0, 0]
Rt = lookat(eye, [0, 0, 0])
print Rt
p = [0, 0, 0]
print cv2.transform(np.float64([[p]]), Rt)
print cv2.SVDecomp(Rt[:,:3])