def calc_seg(self, nEMIters, nItersInner=10, calc_s_cov=True, prior_weight=0.5, verbose=False):
"""
Inference:
hard-EM (Expectation & Maximization)
Alternate between the E step (update superpixel assignments)
and the M step (update parameters)
Arguments:
calc_s_cov: whether or not to update the covariance of color component of Gaussians
prior_weight: the weight placed on the prior probability of a superpixel
"""
if verbose:
print 'start'
for i in range(nEMIters):
if verbose:
print 'iteration',i
"M step"
self._calc_param(img_gpu=self.img.gpu, img_isNaN_gpu =self.img_isNaN.gpu, seg_gpu=self.seg.gpu,
sp=self.superpixels,
calculate_s_cov=calc_s_cov)
"(Hard) E step"
self._calc_seg(img_gpu=self.img.gpu, img_isNaN_gpu =self.img_isNaN.gpu, seg_gpu=self.seg.gpu,
border_gpu=self.border.gpu,
counts_gpu=self.superpixels.params.counts.gpu,
log_count_gpu = self.superpixels.gpu_helper.log_count_helper,
superpixels=self.superpixels,
nIters=nItersInner,
calculate_cov=calc_s_cov,
prior_prob_weight = prior_weight)
# update the border for display the single border image
find_border_pixels(seg_gpu=self.seg.gpu, border_gpu=self.border.gpu, single_border=1)
def calc_seg(self, nEMIters, nItersInner=10, calc_s_cov=True, prior_weight=0.5, verbose=False):
"""
Inference:
hard-EM (Expectation & Maximization)
Alternate between the E step (update superpixel assignments)
and the M step (update parameters)
Arguments:
calc_s_cov: whether or not to update the covariance of color component of Gaussians
prior_weight: the weight placed on the prior probability of a superpixel
"""
if verbose:
print('start')
for i in range(nEMIters):
if verbose:
print('iteration', i, "M step")
self._calc_param(img_gpu=self.img.gpu, img_isNaN_gpu=self.img_isNaN.gpu, seg_gpu=self.seg.gpu,
sp=self.superpixels,
calculate_s_cov=calc_s_cov)
if verbose:
print("(Hard) E step")
self._calc_seg(img_gpu=self.img.gpu, img_isNaN_gpu=self.img_isNaN.gpu, seg_gpu=self.seg.gpu,
border_gpu=self.border.gpu,
counts_gpu=self.superpixels.params.counts.gpu,
log_count_gpu=self.superpixels.gpu_helper.log_count_helper,
superpixels=self.superpixels,
nIters=nItersInner,
calculate_cov=calc_s_cov,
prior_prob_weight=prior_weight)
# update the border for display the single border image
find_border_pixels(seg_gpu=self.seg.gpu, border_gpu=self.border.gpu, single_border=1)
def __init__(self,
dimy,
dimx,
nPixels_in_square_side=None,
permute_seg=False,
s_std=20,
i_std=20,
prior_count=1,
calc_s_cov=True,
use_hex=False):
"""
arguments:
nPixels_in_square_side: number of the pixels on the side of a superpixels
permute_seg: only for display purpose, whether to permute the superpixels labling,
s_std: fixed as nPixels_on_side
i_std: control the relative importance between RGB and location.
The smaller it is, bigger the RGB effect is / more irregular the superpixels are.
prior_count: determines the weight of Inverse-Wishart prior of space covariance(ex:1,5,10)
calc_s_cov: whether or not to update the covariance of color component of Gaussians
use_hex: initialize the superpixels as hexagons or squares
"""
# init the field "nPixels_in_square_side"
if nPixels_in_square_side is None:
raise NotImplementedError
self.nPixels_in_square_side = nPixels_in_square_side
if not (3 < nPixels_in_square_side < min(dimx, dimy)):
msg = """
Expected
3<nPixels_in_square_side<min(dimx,dimy)={1}
but nPixels_in_square_side={0}
""".format(nPixels_in_square_side, min(dimx, dimy))
raise ValueError(msg)
self.dimx = dimx
self.dimy = dimy
self.nChannels = 3 # RGB/LAB
#init the field "seg"
self.use_hex = use_hex
self.permute_seg = permute_seg
seg = get_init_seg(dimy=dimy,
dimx=dimx,
nPixels_in_square_side=nPixels_in_square_side,
use_hex=use_hex)
if permute_seg:
seg = random_permute_seg(seg)
self.seg = CpuGpuArray(arr=seg)
# keep the initial segmentation for use in images of the same size
# so that we won't re-calculate the initial segmenation
self.seg_ini = self.seg.cpu.copy()
#init the field nSuperpixels
self.nSuperpixels = self.seg.cpu.max() + 1
if self.nSuperpixels <= 1:
raise ValueError(self.nSuperpixels)
#init the field "superpixels"
self.superpixels = Superpixels(self.nSuperpixels,
s_std=s_std,
i_std=i_std,
prior_count=prior_count,
nChannels=self.nChannels)
#init the field "border"(bool array, true for pixels on the superpixel boundary)
border = gpuarray.zeros((dimy, dimx), dtype=np.bool)
self.border = CpuGpuArray(arr=border)
find_border_pixels(seg_gpu=self.seg.gpu, border_gpu=self.border.gpu)
self.border.gpu2cpu()
self.border_ini = self.border.cpu.copy()
print('dimy,dimx=', dimy, dimx)
print('nSuperpixels =', self.nSuperpixels)
def __init__(self, dimy, dimx, nPixels_in_square_side=None, permute_seg=False,
s_std = 20, i_std=20, prior_count = 1,
calc_s_cov=True,
use_hex=False):
"""
arguments:
nPixels_in_square_side: number of the pixels on the side of a superpixels
permute_seg: only for display purpose, whether to permute the superpixels labling,
s_std: fixed as nPixels_on_side
i_std: control the relative importance between RGB and location.
The smaller it is, bigger the RGB effect is / more irregular the superpixels are.
prior_count: determines the weight of Inverse-Wishart prior of space covariance(ex:1,5,10)
calc_s_cov: whether or not to update the covariance of color component of Gaussians
use_hex: initialize the superpixels as hexagons or squares
"""
# init the field "nPixels_in_square_side"
if nPixels_in_square_side is None:
raise NotImplementedError
self.nPixels_in_square_side=nPixels_in_square_side
if not (3<nPixels_in_square_side<min(dimx,dimy)):
msg = """
Expected
3<nPixels_in_square_side<min(dimx,dimy)={1}
but nPixels_in_square_side={0}
""".format(nPixels_in_square_side,min(dimx,dimy))
raise ValueError(msg)
self.dimx=dimx
self.dimy=dimy
self.nChannels = 3 # RGB/LAB
#init the field "seg"
self.use_hex = use_hex
self.permute_seg = permute_seg
seg = get_init_seg(dimy=dimy,dimx=dimx,
nPixels_in_square_side=nPixels_in_square_side, use_hex = use_hex)
if permute_seg:
seg = random_permute_seg(seg)
self.seg = CpuGpuArray(arr=seg)
# keep the initial segmentation for use in images of the same size
# so that we won't re-calculate the initial segmenation
self.seg_ini = self.seg.cpu.copy()
#init the field nSuperpixels
self.nSuperpixels = self.seg.cpu.max()+1
if self.nSuperpixels <= 1:
raise ValueError(self.nSuperpixels)
#init the field "superpixels"
self.superpixels = Superpixels(self.nSuperpixels,
s_std=s_std, i_std=i_std, prior_count = prior_count,
nChannels=self.nChannels)
#init the field "border"(bool array, true for pixels on the superpixel boundary)
border = gpuarray.zeros((dimy,dimx),dtype=np.bool)
self.border = CpuGpuArray(arr=border)
find_border_pixels(seg_gpu=self.seg.gpu, border_gpu=self.border.gpu)
self.border.gpu2cpu()
self.border_ini = self.border.cpu.copy()
print 'dimy,dimx=',dimy,dimx
print 'nSuperpixels =',self.nSuperpixels
