def iasobel(f):
import numpy as np
from ia636 import iaimginfo, iapconv
wx = np.array([[1., 2., 1.], [0., 0., 0.], [-1., -2., -1.]])
wy = np.array([[1., 0., -1.], [2., 0., -2.], [1., 0., -1.]])
gx = iapconv(f, wx)
gy = iapconv(f, wy)
mag = np.abs(gx + gy * 1j)
theta = np.arctan2(gy, gx)
return mag, theta
def iasobel(f):
import numpy as np
from ia636 import iaimginfo, iapconv
wx = np.array([[1.,2.,1.],
[0.,0.,0.],
[-1.,-2.,-1.]])
wy = np.array([[1.,0.,-1.],
[2.,0.,-2.],
[1.,0.,-1.]])
gx = iapconv(f, wx)
gy = iapconv(f, wy)
mag = np.abs(gx + gy*1j)
theta = np.arctan2(gy,gx)
return mag,theta
def iaptrans2(f, t):
from ia636 import iapconv
f, t = asarray(f), asarray(t).astype(int32)
h = zeros(2*abs(t) + 1)
t = t + abs(t)
h[tuple(t)] = 1
g = iapconv(f, h)
return g
def iaptrans2(f, t):
from ia636 import iapconv
f, t = asarray(f), asarray(t).astype(int32)
h = zeros(2 * abs(t) + 1)
t = t + abs(t)
h[tuple(t)] = 1
g = iapconv(f, h)
return g
def iavarfilter(f,h,CV=True):
from ia636 import iapconv
f = asarray(f).astype(float64)
h = asarray(h).astype(bool)[::-1,::-1]
n = sum(ravel(h))
h = h/float(n)
fm = iapconv(f, h)
f2m = iapconv(f**2, h)
g = f2m - fm**2
if (CV):
fm = fm + 1e-320*(fm == 0) # change zero by a very small number (prevent 'math range error')
g[g<0.0] = 0.0 # avoid negative numbers due to numeric precision
g = sqrt(g) / fm
return g
def iavarfilter(f, h, CV=True):
from ia636 import iapconv
f = asarray(f).astype(float64)
h = asarray(h).astype(bool)[::-1, ::-1]
n = sum(ravel(h))
h = h / float(n)
fm = iapconv(f, h)
f2m = iapconv(f**2, h)
g = f2m - fm**2
if (CV):
fm = fm + 1e-320 * (
fm == 0
) # change zero by a very small number (prevent 'math range error')
g[g < 0.0] = 0.0 # avoid negative numbers due to numeric precision
g = sqrt(g) / fm
return g