Add deconvolution module to skimage.

This module add three function to skimage. The `wiener` function is a
simple wiener deconvolution. The `unsupervised_wiener` is a more
sophisticated wiener deconvolution with automatic estimation of
regularisation parameters. The third function is a literal traduction
in python of the rychardson lucy deconvolution of wikipedia.

skimage/deconvolution/test/test_deconvolution.py

@@ -0,0 +1,38 @@
+import warnings
+
+import numpy as np
+import numpy.testing.assert_array_almost_equal
+
+from scipy.signal import convolve2d as conv2
+from skimage import data, deconvolution
+
+# Test deconvolution
+# ===========================
+
+test_img = data.camera().astype(np.float)
+
+
+def test_wiener():
+    psf = np.ones((5, 5))
+    data = conv2(test_img, psf, 'same')
+    np.random.seed(0)
+    data += 0.1 * data.std() * np.random.standard_normal(data.shape)
+    deconvolued = deconvolution.wiener(data, psf, 25)
+
+    numpy.testing.assert_array_almost_equal(deconvolued,
+                                            np.load("./camera_wiener.npy"))
+
+
+def test_unsupervised_wiener():
+    psf = np.ones((5, 5))
+    data = conv2(test_img, psf, 'same')
+    np.random.seed(0)
+    data += 0.1 * data.std() * np.random.standard_normal(data.shape)
+    deconvolued, _ = deconvolution.unsupervised_wiener(data, psf)
+
+    numpy.testing.assert_array_almost_equal(deconvolued,
+                                            np.load("./camera_unsup.npy"))
+
+
+def test_rychardson_lucy():
+    return True