#!/usr/bin/env python

# Module: scipy_image.py

# Purpose: Image test from examples (header added)

# Date: N/A

# Notes:

# 1) from examples

# Ref: http://docs.scipy.org/doc/scipy/reference/tutorial/signal.html

import numpy as np

from scipy import signal, misc

import matplotlib.pyplot as plt

# import the image -- pre-defined

image = misc.lena().astype(np.float32)

# filter the image

derfilt = np.array([1.0, -2, 1.0], dtype=np.float32)

ck = signal.cspline2d(image, 8.0)

deriv = (signal.sepfir2d(ck, derfilt, [1]) +

signal.sepfir2d(ck, [1], derfilt))

laplacian = np.array([[0,1,0], [1,-4,1], [0,1,0]], dtype=np.float32)

deriv2 = signal.convolve2d(ck,laplacian,mode='same',boundary='symm')

# plot the original

plt.figure()

plt.imshow(image)

plt.gray()

plt.title('Original image')

plt.show()

# plot the edge filter

plt.figure()

plt.imshow(deriv)

plt.gray()

plt.title('Output of spline edge filter')

plt.show()