Small Upgrades

eta/core/data.py

@@ -22,6 +22,7 @@
 # pragma pylint: enable=wildcard-import
 
 from collections import defaultdict
+import logging
 import os
 
 import numpy as np
@@ -32,6 +33,9 @@
 import eta.core.utils as etau
 
 
+logger = logging.getLogger(__name__)
+
+
 def majority_vote_categorical_attrs(attrs, confidence_weighted=False):
     '''Performs majority votes over the given attributes, which are assumed to
     be `CategoricalAttribute`s.

eta/core/image.py

@@ -568,6 +568,23 @@ def build_active_schema(cls, image_labels):
                 schema.add_object_label(obj.label)
         return schema
 
+    @classmethod
+    def from_video_labels_schema(cls, video_labels_schema):
+        '''Creates an ImageLabelsSchema from a VideoLabelsSchema.
+
+        Frame-level attributes of the VideoLabelsSchema are converted to
+        image-level attributes in the ImageLabelsSchema.
+
+        Args:
+            video_labels_schema: a VideoLabelsSchema
+
+        Returns:
+            an ImageLabelsSchema
+        '''
+        return cls(
+            attrs=video_labels_schema.frames,
+            objects=video_labels_schema.objects)
+
     @classmethod
     def from_dict(cls, d):
         '''Constructs an ImageLabelsSchema from a JSON dictionary.

eta/core/utils.py

@@ -2522,3 +2522,20 @@ class ExecutableRuntimeError(Exception):
     def __init__(self, cmd, err):
         message = "Command '%s' failed with error:\n%s" % (cmd, err)
         super(ExecutableRuntimeError, self).__init__(message)
+
+
+def validate_type(obj, expected_type):
+    '''Validates an object's type against an expected type.
+
+    Args:
+        obj: the python object to validate
+        expected_type: the type that `obj` must be (via `isinstance`)
+
+    Raises:
+        TypeError: if `obj` is not of `expected_type`
+    '''
+    if not isinstance(obj, expected_type):
+        raise TypeError(
+            "Unexpected argument type:\n\tExpected: %s\n\tActual: %s"
+            % (get_class_name(expected_type), get_class_name(obj))
+        )

eta/core/video.py

@@ -1621,6 +1621,23 @@ def attributes(self):
         '''
         return ["attrs", "frames", "objects", "events"]
 
+    @classmethod
+    def from_image_labels_schema(cls, image_labels_schema):
+        '''Creates a VideoLabelsSchema from an ImageLabelsSchema.
+
+        Image-level attributes of the ImageLabelsSchema are converted to
+        frame-level attributes in the VideoLabelsSchema.
+
+        Args:
+            image_labels_schema: an ImageLabelsSchema
+
+        Returns:
+            a VideoLabelsSchema
+        '''
+        return cls(
+            frames=image_labels_schema.attrs,
+            objects=image_labels_schema.objects)
+
     @classmethod
     def build_active_schema_for_frame(cls, frame_labels):
         '''Builds a VideoLabelsSchema that describes the active schema of the