Online Convolutional Dictionary Learning (CuPy Version)

This example demonstrates the use of onlinecdl.OnlineConvBPDNDictLearn for learning a convolutional dictionary from a set of training images. The dictionary is learned using the online dictionary learning algorithm proposed in [25]. This variant of the example uses the GPU accelerated version of onlinecdl within the sporco.cupy subpackage.

from __future__ import print_function
from builtins import input
from builtins import range

import numpy as np

from sporco import util
from sporco import plot
from sporco.cupy import cupy_enabled, np2cp, cp2np
from sporco.cupy import select_device_by_load, gpu_info
from sporco.cupy import cp
from sporco.cupy.dictlrn import onlinecdl

Load training images.

exim = util.ExampleImages(scaled=True, zoom=0.25)
S1 = exim.image('barbara.png', idxexp=np.s_[10:522, 100:612])
S2 = exim.image('kodim23.png', idxexp=np.s_[:, 60:572])
S3 = exim.image('monarch.png', idxexp=np.s_[:, 160:672])
S4 = exim.image('sail.png', idxexp=np.s_[:, 210:722])
S5 = exim.image('tulips.png', idxexp=np.s_[:, 30:542])
S = np.stack((S1, S2, S3, S4, S5), axis=3)

Highpass filter training images.

npd = 16
fltlmbd = 5
sl, sh = util.tikhonov_filter(S, fltlmbd, npd)

Construct initial dictionary.

D0 = np.random.randn(8, 8, 3, 64)

Set regularization parameter and options for dictionary learning solver.

lmbda = 0.2
opt = onlinecdl.OnlineConvBPDNDictLearn.Options({
                'Verbose': True, 'ZeroMean': False, 'eta_a': 10.0,
                'eta_b': 20.0, 'DataType': np.float32,
                'CBPDN': {'rho': 5.0, 'AutoRho': {'Enabled': True},
                    'RelaxParam': 1.8, 'RelStopTol': 1e-7, 'MaxMainIter': 50,
                    'FastSolve': False, 'DataType': np.float32}})

Create solver object and solve.

if not cupy_enabled():
    print('CuPy/GPU device not available: running without GPU acceleration\n')
    id = select_device_by_load()
    info = gpu_info()
    if info:
        print('Running on GPU %d (%s)\n' % (id, info[id].name))

d = onlinecdl.OnlineConvBPDNDictLearn(np2cp(D0), lmbda, opt)

iter = 50
for it in range(iter):
    img_index = np.random.randint(0, sh.shape[-1])
    d.solve(np2cp(sh[..., [img_index]]))

D1 = cp2np(d.getdict())
print("OnlineConvBPDNDictLearn solve time: %.2fs" % d.timer.elapsed('solve'))
Running on GPU 1 (Tesla K40c)

Itn   X r       X s       X ρ       D cnstr   D dlt     D η
   0  9.81e-04  1.58e-03  5.00e+00  8.04e+01  6.14e+00  5.00e-01
   1  1.86e-03  1.68e-03  5.00e+00  7.55e+01  4.37e+00  4.76e-01
   2  2.86e-03  1.96e-03  5.00e+00  2.51e+01  2.65e+00  4.55e-01
   3  1.79e-03  1.90e-03  5.00e+00  5.09e+01  2.28e+00  4.35e-01
   4  2.37e-03  1.71e-03  5.00e+00  2.09e+01  1.65e+00  4.17e-01
   5  1.80e-03  1.47e-03  5.00e+00  3.52e+01  1.91e+00  4.00e-01
   6  2.27e-03  3.29e-03  5.00e+00  3.57e+01  2.19e+00  3.85e-01
   7  1.69e-03  1.95e-03  5.00e+00  4.50e+01  2.16e+00  3.70e-01
   8  1.65e-03  1.44e-03  5.00e+00  3.18e+01  1.71e+00  3.57e-01
   9  2.02e-03  3.08e-03  5.00e+00  3.20e+01  1.82e+00  3.45e-01
  10  2.09e-03  1.75e-03  5.00e+00  1.72e+01  1.47e+00  3.33e-01
  11  1.86e-03  2.87e-03  5.00e+00  3.01e+01  1.64e+00  3.23e-01
  12  2.09e-03  1.87e-03  5.00e+00  2.56e+01  1.82e+00  3.12e-01
  13  2.40e-03  2.09e-03  5.00e+00  1.53e+01  1.20e+00  3.03e-01
  14  1.90e-03  2.27e-03  5.00e+00  3.59e+01  1.87e+00  2.94e-01
  15  1.97e-03  1.71e-03  5.00e+00  1.44e+01  1.04e+00  2.86e-01
  16  2.13e-03  2.05e-03  5.00e+00  2.23e+01  1.40e+00  2.78e-01
  17  2.17e-03  3.41e-03  5.00e+00  2.64e+01  1.79e+00  2.70e-01
  18  2.04e-03  1.87e-03  5.00e+00  1.34e+01  1.03e+00  2.63e-01
  19  1.79e-03  2.17e-03  5.00e+00  3.07e+01  1.50e+00  2.56e-01
  20  1.98e-03  1.94e-03  5.00e+00  2.05e+01  1.36e+00  2.50e-01
  21  2.21e-03  1.99e-03  5.00e+00  2.15e+01  1.22e+00  2.44e-01
  22  2.08e-03  3.26e-03  5.00e+00  2.31e+01  1.47e+00  2.38e-01
  23  1.78e-03  2.20e-03  5.00e+00  2.82e+01  1.37e+00  2.33e-01
  24  1.90e-03  1.85e-03  5.00e+00  1.86e+01  1.18e+00  2.27e-01
  25  2.12e-03  1.93e-03  5.00e+00  2.00e+01  1.12e+00  2.22e-01
  26  1.77e-03  2.20e-03  5.00e+00  2.63e+01  1.20e+00  2.17e-01
  27  1.62e-03  2.10e-03  5.00e+00  2.55e+01  8.04e-01  2.13e-01
  28  1.57e-03  2.09e-03  5.00e+00  2.52e+01  6.65e-01  2.08e-01
  29  1.83e-03  1.72e-03  5.00e+00  1.66e+01  1.16e+00  2.04e-01
  30  1.68e-03  2.21e-03  5.00e+00  2.46e+01  8.82e-01  2.00e-01
  31  1.93e-03  1.76e-03  5.00e+00  1.77e+01  1.11e+00  1.96e-01
  32  1.65e-03  1.52e-03  5.00e+00  1.79e+01  8.01e-01  1.92e-01
  33  1.85e-03  1.73e-03  5.00e+00  1.54e+01  9.75e-01  1.89e-01
  34  1.71e-03  2.25e-03  5.00e+00  2.31e+01  1.11e+00  1.85e-01
  35  1.95e-03  1.92e-03  5.00e+00  1.49e+01  8.52e-01  1.82e-01
  36  1.66e-03  2.19e-03  5.00e+00  2.22e+01  8.43e-01  1.79e-01
  37  1.95e-03  1.98e-03  5.00e+00  1.45e+01  7.60e-01  1.75e-01
  38  2.04e-03  1.91e-03  5.00e+00  1.60e+01  9.32e-01  1.72e-01
  39  1.62e-03  2.13e-03  5.00e+00  2.13e+01  9.33e-01  1.69e-01
  40  2.25e-03  3.39e-03  5.00e+00  1.63e+01  1.45e+00  1.67e-01
  41  1.96e-03  3.07e-03  5.00e+00  1.56e+01  1.04e+00  1.64e-01
  42  1.81e-03  2.88e-03  5.00e+00  1.54e+01  9.35e-01  1.61e-01
  43  1.70e-03  2.72e-03  5.00e+00  1.54e+01  9.57e-01  1.59e-01
  44  1.87e-03  1.62e-03  5.00e+00  1.39e+01  8.95e-01  1.56e-01
  45  1.98e-03  1.90e-03  5.00e+00  1.27e+01  9.39e-01  1.54e-01
  46  1.90e-03  3.08e-03  5.00e+00  1.51e+01  9.98e-01  1.52e-01
  47  1.76e-03  2.22e-03  5.00e+00  1.88e+01  1.15e+00  1.49e-01
  48  1.71e-03  2.84e-03  5.00e+00  1.47e+01  8.75e-01  1.47e-01
  49  1.93e-03  1.89e-03  5.00e+00  1.20e+01  8.04e-01  1.45e-01
OnlineConvBPDNDictLearn solve time: 55.20s

Display initial and final dictionaries.

D1 = D1.squeeze()
fig = plot.figure(figsize=(14, 7))
plot.subplot(1, 2, 1)
plot.imview(util.tiledict(D0), title='D0', fig=fig)
plot.subplot(1, 2, 2)
plot.imview(util.tiledict(D1), title='D1', fig=fig)

Get iterations statistics from solver object and plot functional value.

its = d.getitstat()
fig = plot.figure(figsize=(7, 7))
plot.plot(np.vstack((its.DeltaD, its.Eta)).T, xlbl='Iterations',
          lgnd=('Delta D', 'Eta'), fig=fig)