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import scipy.misc | |
import numpy as np | |
import matplotlib.pyplot as plt | |
import math | |
hx = 7.5 | |
hy = 6.3 | |
fi = -15 * np.pi / 180 | |
kx = 1.2 | |
ky = 0.9 | |
img = scipy.misc.lena() | |
Nx = img.shape[0] | |
Ny = img.shape[1] | |
x0 = (Nx-1)/2 | |
y0 = (Ny-1)/2 | |
H = np.array([[hx], [hy]]) | |
F = np.array([[np.cos(fi), -np.sin(fi)], | |
[np.sin(fi), np.cos(fi)]]) | |
K = np.array([[kx, 0], | |
[0, ky]]) | |
O = np.array([[1, 0], | |
[0, -1]]) | |
Aff = np.array([[1.3, 0.5], | |
[0.2, 1.1]]) | |
A = np.eye(2, 2) | |
X = np.zeros([2, 1]) | |
def interpolate(img, x, y): | |
drob_x = math.modf(x)[0] | |
int_x = math.modf(x)[1] | |
drob_y = math.modf(y)[0] | |
int_y = math.modf(y)[1] | |
res_x = int_x if drob_x < 0.5 else int_x + 1 | |
res_y = int_y if drob_y < 0.5 else int_y + 1 | |
if res_x >= 0 and res_x < Nx and res_y >= 0 and res_y < Ny: | |
return img[res_x, res_y] | |
return 0 | |
def action(img, A, X): | |
result = np.zeros([Nx, Ny]) | |
for i in range(Nx): | |
for j in range(Ny): | |
v = np.array([[i - x0], [j - y0]]) | |
v = np.dot(A, v) + X | |
result[i, j] = interpolate(img, v[0,0] + x0, v[1,0] + y0) | |
return result | |
def move(img): | |
return action(img, A, H) | |
def turn(img): | |
return action(img, F, X) | |
def scale(img): | |
return action(img, K, X) | |
def mirror(img): | |
return action(img, O, X) | |
def compose(img): | |
a = np.dot(F, K) | |
a = np.dot(a, O) | |
return action(img, a, H) | |
def affine(img): | |
return action(img, Aff, X) | |
def inv_affine(img): | |
a = np.linalg.inv(Aff) | |
return action(img, a, X) | |
#move_img = move(img) | |
#turn_img = turn(move_img) | |
#scale_img = scale(turn_img) | |
#mirror_img = mirror(scale_img) | |
#compose_img = compose(img) | |
affine_img = affine(img) | |
inv_affine_img = inv_affine(affine_img) | |
#plt.matshow(move_img) | |
#plt.matshow(turn_img) | |
#plt.matshow(scale_img) | |
#plt.matshow(mirror_img) | |
#plt.matshow(compose_img) | |
plt.gray() | |
plt.matshow(affine_img) | |
plt.matshow(inv_affine_img) | |
plt.show() |
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