def segment_mc(pred, seg, delta):
rag = feats.compute_rag(seg)
edge_probs = embed.edge_probabilities_from_embeddings(
pred, seg, rag, delta)
edge_sizes = feats.compute_boundary_mean_and_length(rag, pred[0])[:, 1]
costs = mc.transform_probabilities_to_costs(edge_probs,
edge_sizes=edge_sizes)
mc_seg = mc.multicut_kernighan_lin(rag, costs)
mc_seg = feats.project_node_labels_to_pixels(rag, mc_seg)
return mc_seg
def supervoxel_merging(mem, sv, beta=0.5, verbose=False):
rag = feats.compute_rag(sv)
costs = feats.compute_boundary_features(rag, mem)[:, 0]
edge_sizes = feats.compute_boundary_mean_and_length(rag, mem)[:, 1]
costs = mc.transform_probabilities_to_costs(costs,
edge_sizes=edge_sizes,
beta=beta)
node_labels = mc.multicut_kernighan_lin(rag, costs)
segmentation = feats.project_node_labels_to_pixels(rag, node_labels)
return segmentation
def segment_volume_lmc_from_seg(boundary_pmaps,
nuclei_seg,
threshold=0.4,
sigma=2.0,
sp_min_size=100):
watershed = distance_transform_watershed(boundary_pmaps,
threshold,
sigma,
min_size=sp_min_size)[0]
# compute the region adjacency graph
rag = compute_rag(watershed)
# compute the edge costs
features = compute_boundary_mean_and_length(rag, boundary_pmaps)
costs, sizes = features[:, 0], features[:, 1]
# transform the edge costs from [0, 1] to [-inf, inf], which is
# necessary for the multicut. This is done by intepreting the values
# as probabilities for an edge being 'true' and then taking the negative log-likelihood.
# in addition, we weight the costs by the size of the corresponding edge
# we choose a boundary bias smaller than 0.5 in order to
# decrease the degree of over segmentation
boundary_bias = .6
costs = transform_probabilities_to_costs(costs,
edge_sizes=sizes,
beta=boundary_bias)
max_cost = np.abs(np.max(costs))
lifted_uvs, lifted_costs = lifted_problem_from_segmentation(
rag,
watershed,
nuclei_seg,
overlap_threshold=0.2,
graph_depth=4,
same_segment_cost=5 * max_cost,
different_segment_cost=-5 * max_cost)
# solve the full lifted problem using the kernighan lin approximation introduced in
# http://openaccess.thecvf.com/content_iccv_2015/html/Keuper_Efficient_Decomposition_of_ICCV_2015_paper.html
node_labels = lmc.lifted_multicut_kernighan_lin(rag, costs, lifted_uvs,
lifted_costs)
lifted_segmentation = project_node_labels_to_pixels(rag, node_labels)
return lifted_segmentation
affs = np.transpose(affs.cpu().numpy(), (1, 0, 2, 3))
gt_affs = np.transpose(gt_affs.cpu().numpy(), (1, 0, 2, 3))
seg = seg.cpu().numpy()
gt_seg = gt_seg.cpu().numpy()
boundary_input = np.mean(affs, axis=0)
gt_boundary_input = np.mean(gt_affs, axis=0)
rag = feats.compute_rag(seg)
# edges rag.uvIds() [[1, 2], ...]
costs = feats.compute_affinity_features(rag, affs, offsets)[:, 0]
gt_costs = calculate_gt_edge_costs(rag.uvIds(), seg.squeeze(),
gt_seg.squeeze())
edge_sizes = feats.compute_boundary_mean_and_length(rag, boundary_input)[:, 1]
gt_edge_sizes = feats.compute_boundary_mean_and_length(rag,
gt_boundary_input)[:, 1]
costs = mc.transform_probabilities_to_costs(costs, edge_sizes=edge_sizes)
gt_costs = mc.transform_probabilities_to_costs(gt_costs, edge_sizes=edge_sizes)
node_labels = mc.multicut_kernighan_lin(rag, costs)
gt_node_labels = mc.multicut_kernighan_lin(rag, gt_costs)
segmentation = feats.project_node_labels_to_pixels(rag, node_labels)
gt_segmentation = feats.project_node_labels_to_pixels(rag, gt_node_labels)
plt.imshow(
np.concatenate(
(gt_segmentation.squeeze(), segmentation.squeeze(), seg.squeeze()),
axis=1))
plt.show()
def refine_seg(raw,
seeds,
restrict_to_seeds=True,
restrict_to_bb=False,
return_intermediates=False):
pred = get_prediction(raw, cache=False)
n_threads = 1
# make watershed
ws, _ = stacked_watershed(pred,
threshold=.5,
sigma_seeds=1.,
n_threads=n_threads)
rag = compute_rag(ws, n_threads=n_threads)
edge_feats = compute_boundary_mean_and_length(rag,
pred,
n_threads=n_threads)
edge_feats, edge_sizes = edge_feats[:, 0], edge_feats[:, 1]
z_edges = compute_z_edge_mask(rag, ws)
edge_costs = compute_edge_costs(edge_feats,
beta=.4,
weighting_scheme='xyz',
edge_sizes=edge_sizes,
z_edge_mask=z_edges)
# make seeds and map them to edges
bb = tuple(
slice(sh // 2 - ha // 2, sh // 2 + ha // 2)
for sh, ha in zip(pred.shape, seeds.shape))
seeds[seeds < 0] = 0
seeds = vigra.analysis.labelVolumeWithBackground(seeds.astype('uint32'))
seed_ids = np.unique(seeds)
seed_mask = binary_erosion(seeds, iterations=2)
seeds_new = seeds.copy()
seeds_new[~seed_mask] = 0
seed_ids_new = np.unique(seeds_new)
for seed_id in seed_ids:
if seed_id in seed_ids_new:
continue
seeds_new[seeds == seed_id] = seed_id
seeds_full = np.zeros(pred.shape, dtype=seeds.dtype)
seeds_full[bb] = seeds
seeds = seeds_full
seed_labels = compute_maximum_label_overlap(ws, seeds, ignore_zeros=True)
edge_ids = rag.uvIds()
labels_u = seed_labels[edge_ids[:, 0]]
labels_v = seed_labels[edge_ids[:, 1]]
seed_mask = np.logical_and(labels_u != 0, labels_v != 0)
same_seed = np.logical_and(seed_mask, labels_u == labels_v)
diff_seed = np.logical_and(seed_mask, labels_u != labels_v)
max_att = edge_costs.max() + .1
max_rep = edge_costs.min() - .1
edge_costs[same_seed] = max_att
edge_costs[diff_seed] = max_rep
# run multicut
node_labels = multicut_kernighan_lin(rag, edge_costs)
if restrict_to_seeds:
seed_nodes = np.unique(node_labels[seed_labels > 0])
node_labels[~np.isin(node_labels, seed_nodes)] = 0
vigra.analysis.relabelConsecutive(node_labels, out=node_labels)
seg = project_node_labels_to_pixels(rag, node_labels, n_threads=n_threads)
if restrict_to_bb:
bb_mask = np.zeros(seg.shape, dtype='bool')
bb_mask[bb] = 1
seg[~bb_mask] = 0
if return_intermediates:
return pred, ws, seeds, seg
else:
return seg
