add indoor sample points

mmdet3d/datasets/pipelines/indoor_sample.py

+import numpy as np
+
+from mmdet.datasets.registry import PIPELINES
+
+
+def points_random_sampling(points,
+                           num_samples,
+                           replace=None,
+                           return_choices=False):
+    """Points Random Sampling
+
+    Sample points to a certain number.
+
+    Args:
+        points (ndarray): 3D Points.
+        num_samples (int): Number of samples to be sampled.
+    """
+    if replace is None:
+        replace = (points.shape[0] < num_samples)
+    choices = np.random.choice(points.shape[0], num_samples, replace=replace)
+    if return_choices:
+        return points[choices], choices
+    else:
+        return points[choices]
+
+
+@PIPELINES.register_module
+class IndoorSamplePoints(object):
+    """Indoor Sample Points
+
+    Sampling data to a certain number.
+
+    Args:
+        name (str): Name of the dataset.
+        num_points (int): Number of points to be sampled.
+    """
+
+    def __init__(self, name, num_points):
+        assert name in ['scannet', 'sunrgbd']
+        self.name = name
+        self.num_points = num_points
+
+    def __call__(self, results):
+        points = results.get('points', None)
+        pcl_color = results.get('pcl_color', None)
+        points, choices = points_random_sampling(
+            points, self.num_points, return_choices=True)
+        results['points'] = points
+
+        if self.name == 'scannet':
+            pcl_color = pcl_color[choices]
+            instance_labels = results.get('instance_labels', None)
+            semantic_labels = results.get('semantic_labels', None)
+            instance_labels = instance_labels[choices]
+            semantic_labels = semantic_labels[choices]
+            results['instance_labels'] = instance_labels
+            results['semantic_labels'] = semantic_labels
+            results['pcl_color'] = pcl_color
+
+        return results
+
+    def __repr__(self):
+        repr_str = self.__class__.__name__
+        repr_str += '(num_points={})'.format(self.num_points)
+        return repr_str