Also known as the kinematic model, this representative includes a set of keypoints (joints) like ankles, knees, shoulders, etc.
class Skeleton:
"""
A skeleton model with a number of joints and limb orientation.
Attributes:
parents -- An array with all the parent nodes for each of the joints.
joints_left -- All the joints to the left of our skeleton model.
joints_right -- All the joints to the right of our skeleton model.
"""
def __init__(self, parents, joints_left, joints_right):
assert len(joints_left) == len(joints_right), "Skeleton is not symmetric."
self._parents = np.array(parents)
self._joints_left = joints_left
self._joints_right = joints_right
self._compute_metadata()
def remove_joints(self, joints_to_remove):
"""
Remove the joints specified in 'joints_to_remove'.
return: A list with all the remaining nodes after removal.
"""
valid_joints = []
for joint in range(len(self._parents)):
if joint not in joints_to_remove:
valid_joints.append(joint)
for i in range(len(self._parents)):
while self._parents[i] in joints_to_remove:
self._parents[i] = self._parents[self._parents[i]]
index_offsets = np.zeros(len(self._parents), dtype=int)
new_parents = []
for i, parent in enumerate(self._parents):
if i not in joints_to_remove:
new_parents.append(parent - index_offsets[parent])
else:
index_offsets[i:] += 1
self._parents = np.array(new_parents)
# Re-assigns the remaining joints to left and right respectivly.
if self._joints_left is not None:
new_joints_left = []
for joint in self._joints_left:
if joint in valid_joints:
new_joints_left.append(joint - index_offsets[joint])
self._joints_left = new_joints_left
if self._joints_right is not None:
new_joints_right = []
for joint in self._joints_right:
if joint in valid_joints:
new_joints_right.append(joint - index_offsets[joint])
self._joints_right = new_joints_right
self._compute_metadata()
return valid_joints
def _compute_metadata(self):
self._has_children = np.zeros(len(self._parents)).astype(bool)
for _, parent in enumerate(self._parents):
if parent != -1:
self._has_children[parent] = True
self._children = []
for _, parent in enumerate(self._parents):
self._children.append([])
for i, parent in enumerate(self._parents):
if parent != -1:
self._children[parent].append(i)
# Bunch of getter methods.
def num_joints(self):
return len(self._parents)
def parents(self):
return self._parents
def has_children(self):
return self._has_children
def children(self):
return self._childre
def joints_left(self):
return self._joints_left
def joints_right(self):
return self._joints_right