Merge pull request #144 from aaren/import-images

Add importable images

demo/dwt2_dwtn_image.py

@@ -3,13 +3,13 @@
 
 import numpy as np
 import matplotlib.pyplot as plt
-from scipy import ndimage
 
 import pywt
+import pywt.data
 
 
 # Load image
-original = ndimage.imread('data/aero.png', mode='L')
+original = pywt.data.aero()
 
 # Wavelet transform of image, and plot approximation and details
 titles = ['Approximation', ' Horizontal detail',

demo/dwt_signal_decomposition.py

@@ -1,15 +1,14 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
-import os
-
 import numpy as np
 import matplotlib.pyplot as plt
 
 import pywt
+import pywt.data
 
 
-ecg = np.load(os.path.join('data', 'ecg.npy'))
+ecg = pywt.data.ecg()
 
 data1 = np.concatenate((np.arange(1, 400),
                         np.arange(398, 600),

demo/dwt_swt_show_coeffs.py

@@ -1,15 +1,15 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
-import os
-
 import numpy as np
 import matplotlib.pyplot as plt
 
 import pywt
+import pywt.data
+
 
+ecg = pywt.data.ecg()
 
-ecg = np.load(os.path.join('data', 'ecg.npy'))
 data1 = np.concatenate((np.arange(1, 400),
                         np.arange(398, 600),
                         np.arange(601, 1024)))

demo/swt2.py

@@ -1,16 +1,13 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
-import numpy as np
 import matplotlib.pyplot as plt
-from PIL import Image
 
 import pywt
+import pywt.data
 
 
-im = Image.open("data/aero.png").convert('L')
-arr = np.fromstring(im.tostring(), np.uint8)
-arr.shape = (im.size[1], im.size[0])
+arr = pywt.data.aero()
 
 plt.imshow(arr, interpolation="nearest", cmap=plt.cm.gray)
 

demo/wp_2d.py

@@ -3,14 +3,12 @@
 
 import numpy as np
 import matplotlib.pyplot as plt
-from PIL import Image
 
 from pywt import WaveletPacket2D
+import pywt.data
 
 
-im = Image.open("data/aero.png").convert('L')
-arr = np.fromstring(im.tostring(), np.uint8)
-arr.shape = (im.size[1], im.size[0])
+arr = pywt.data.aero()
 
 wp2 = WaveletPacket2D(arr, 'db2', 'symmetric', maxlevel=2)
 

demo/wp_visualize_coeffs_distribution.py

@@ -7,9 +7,11 @@
 import matplotlib.pyplot as plt
 
 from pywt import WaveletPacket
+import pywt.data
 
 
-ecg = np.load(os.path.join('data', 'ecg.npy'))
+ecg = pywt.data.ecg()
+
 wp = WaveletPacket(ecg, 'sym5', maxlevel=4)
 
 fig = plt.figure()

pywt/__init__.py

@@ -19,6 +19,7 @@
 from ._thresholding import *
 from ._wavelet_packets import *
 
+from . import data
 
 __all__ = [s for s in dir() if not s.startswith('_')]
 try:

pywt/data/__init__.py

@@ -0,0 +1 @@
+from ._readers import ascent, aero, ecg, camera

pywt/data/_readers.py

@@ -0,0 +1,135 @@
+import os
+
+import numpy as np
+
+
+def ascent():
+    """
+    Get an 8-bit grayscale bit-depth, 512 x 512 derived image for
+    easy use in demos
+
+    The image is derived from accent-to-the-top.jpg at
+    http://www.public-domain-image.com/people-public-domain-images-pictures/
+
+    Parameters
+    ----------
+    None
+
+    Returns
+    -------
+    ascent : ndarray
+       convenient image to use for testing and demonstration
+
+    Examples
+    --------
+    >>> import pywt.data
+    >>> ascent = pywt.data.ascent()
+    >>> ascent.shape
+    (512, 512)
+    >>> ascent.max()
+    255
+
+    >>> import matplotlib.pyplot as plt
+    >>> plt.gray()
+    >>> plt.imshow(ascent)
+    >>> plt.show()
+
+    """
+    fname = os.path.join(os.path.dirname(__file__), 'ascent.npz')
+    ascent = np.load(fname)['data']
+    return ascent
+
+
+def aero():
+    """
+    Get an 8-bit grayscale bit-depth, 512 x 512 derived image for
+    easy use in demos
+
+    Parameters
+    ----------
+    None
+
+    Returns
+    -------
+    aero : ndarray
+       convenient image to use for testing and demonstration
+
+    Examples
+    --------
+    >>> import pywt.data
+    >>> aero = pywt.data.ascent()
+    >>> aero.shape
+    (512, 512)
+    >>> aero.max()
+    255
+
+    >>> import matplotlib.pyplot as plt
+    >>> plt.gray()
+    >>> plt.imshow(aero)
+    >>> plt.show()
+
+    """
+    fname = os.path.join(os.path.dirname(__file__), 'aero.npz')
+    aero = np.load(fname)['data']
+    return aero
+
+
+def camera():
+    """
+    Get an 8-bit grayscale bit-depth, 512 x 512 derived image for
+    easy use in demos
+
+    Parameters
+    ----------
+    None
+
+    Returns
+    -------
+    camera : ndarray
+       convenient image to use for testing and demonstration
+
+    Examples
+    --------
+    >>> import pywt.data
+    >>> camera = pywt.data.ascent()
+    >>> camera.shape
+    (512, 512)
+
+    >>> import matplotlib.pyplot as plt
+    >>> plt.gray()
+    >>> plt.imshow(camera)
+    >>> plt.show()
+
+    """
+    fname = os.path.join(os.path.dirname(__file__), 'camera.npz')
+    camera = np.load(fname)['data']
+    return camera
+
+
+def ecg():
+    """
+    Get 1024 points of an ECG timeseries.
+
+    Parameters
+    ----------
+    None
+
+    Returns
+    -------
+    ecg : ndarray
+       convenient timeseries to use for testing and demonstration
+
+    Examples
+    --------
+    >>> import pywt.data
+    >>> ecg = pywt.data.ecg()
+    >>> ecg.shape
+    (1024,)
+
+    >>> import matplotlib.pyplot as plt
+    >>> plt.plot(ecg)
+    >>> plt.show()
+    """
+    fname = os.path.join(os.path.dirname(__file__), 'ecg.npy')
+    ecg = np.load(fname)
+    return ecg

pywt/data/create_dat.py

@@ -0,0 +1,32 @@
+#!/usr/bin/env python
+
+"""Helper script for creating image .dat files by numpy.save
+
+Usage:
+
+    python create_dat.py <name of image file> <name of dat file>
+
+Example (to create aero.dat):
+
+    python create_dat.py aero.png aero.dat
+
+Requires Scipy and PIL.
+"""
+
+from __future__ import print_function
+
+import sys
+
+import numpy as np
+from scipy.misc import imread
+
+if len(sys.argv) != 3:
+    print(__doc__)
+    exit()
+
+image_fname = sys.argv[1]
+dat_fname = sys.argv[2]
+
+data = imread(image_fname)
+
+np.savez_compressed(dat_fname, data=data)

pywt/tests/test_data.py

@@ -0,0 +1,42 @@
+import numpy as np
+from numpy.testing import assert_allclose
+
+import pywt.data
+
+
+def test_data_aero():
+    aero = pywt.data.aero()
+
+    ref = np.array([[178, 178, 179],
+                    [170, 173, 171],
+                    [185, 174, 171]])
+
+    assert_allclose(aero[:3, :3], ref)
+
+
+def test_data_ascent():
+    ascent = pywt.data.ascent()
+
+    ref = np.array([[83, 83, 83],
+                    [82, 82, 83],
+                    [80, 81, 83]])
+
+    assert_allclose(ascent[:3, :3], ref)
+
+
+def test_data_camera():
+    ascent = pywt.data.camera()
+
+    ref = np.array([[156, 157, 160],
+                    [156, 157, 159],
+                    [158, 157, 156]])
+
+    assert_allclose(ascent[:3, :3], ref)
+
+
+def test_data_ecg():
+    ecg = pywt.data.ecg()
+
+    ref = np.array([-86, -87, -87])
+
+    assert_allclose(ecg[:3], ref)

setup.py

@@ -131,6 +131,9 @@ def configuration(parent_package='',top_path=None):
                        quiet=True)
 
     config.add_subpackage('pywt')
+    config.add_subpackage('pywt/data')
+    config.add_data_files('pywt/data/*npz')
+    config.add_data_files('pywt/data/*npy')
 
     config.get_version('pywt/version.py')
     return config