def decode_svd(codebook, domain_blocks):
# if domain_blocks.mode != 'equipartition4' or\
# domain_blocks.mode !=:
# raise Exception("encode_svd only supports 'equipartition4' partitioning")
num_weights = len(domain_blocks[0].ravel())
X = np.zeros([num_weights, len(domain_blocks)])
for i in range(len(domain_blocks)):
X[:, i] = np.ravel(domain_blocks[i])
u, s, vh = randomized_svd(X,
n_components=min(X.shape[1], 1000),
n_iter=5,
random_state=None)
N = int(np.sqrt(len(codebook)))
img = utils.init_range_image(N, domain_blocks)
range_blocks = utils.Partition(img, mode=domain_blocks.mode)
nrows = int(np.sqrt(num_weights))
ncols = nrows
for ridx, weights in enumerate(codebook):
range_blocks[ridx] = np.dot(u, weights[:, np.newaxis])\
.reshape(nrows, ncols)
return range_blocks
def decode_nmf(codebook, domain_blocks):
# if domain_blocks.mode != 'equipartition4' or\
# domain_blocks.mode !=:
# raise Exception("encode_svd only supports 'equipartition4' partitioning")
num_weights = len(domain_blocks[0].ravel())
X = np.zeros([num_weights, len(domain_blocks)])
for i in range(len(domain_blocks)):
X[:, i] = np.ravel(domain_blocks[i])
X = np.abs(X)
model = NMF(n_components=16, init='random', random_state=0)
_ = model.fit_transform(X)
u = model.components_[:,:16]
N = int(np.sqrt(len(codebook)))
img = utils.init_range_image(N, domain_blocks)
range_blocks = utils.Partition(img, mode=domain_blocks.mode)
nrows = int(np.sqrt(num_weights))
ncols = nrows
for ridx, weights in enumerate(codebook):
range_blocks[ridx] = np.dot(u, weights[:, np.newaxis])\
.reshape(nrows, ncols)
return range_blocks
def decode(codebook, domain_blocks):
"""Decodes the codebook into estimates of the range blocks"""
N = int(np.sqrt(len(codebook)))
if N != np.sqrt(len(codebook)):
raise Exception("Codebook size must correspond to a square range image")
# create a range block partition to populate
img = utils.init_range_image(N, domain_blocks)
range_blocks = utils.Partition(img, mode=domain_blocks.mode)
for ridx, (didx, permtype, alpha, t0) in enumerate(codebook):
permtype = int(permtype)
dref = domain_blocks[didx]
db = permute(dref)[permtype]
range_blocks[ridx] = (alpha * db) + t0
return range_blocks