New functionality for counting TFRecord examples

README.md

@@ -255,6 +255,30 @@ $ cvdata_mask --images /data/images --masks /data/masks \
 >       --tfrecords /data/tfrecords \
 >       --shards 4 -- train_pct 0.8
 ```
+## Dataset statistics
+Basic statistics about a dataset are available via the script `cvdata/analyze.py` 
+or the corresponding script entry point `cvdata_analyze`.
+
+For example, we can count the number of examples in a collection of TFRecord files 
+(specify a directory containing only TFRecod files):
+```bash
+$ cvdata_analyze --format tfrecord --annotations /data/animals/tfrecord
+Total number of examples: 100
+```
+The above functionality can be utilized within Python code like so:
+```python
+from cvdata.analyze import count_tfrecord_examples
+tfrecords_dir = "/data/animals/tfrecord"
+number_of_examples = count_tfrecord_examples(tfrecords_dir)
+print(f"Number of examples: {number_of_examples}")
+```
+For datasets containing annotation files in COCO, Darknet (YOLO), KITTI, or PASCAL 
+formats we can get the number of images per class label. For example:
+```bash
+$ cvdata_analyze --format kitti --annotations /data/scissors/kitti --images /data/scissors/images
+Label: scissors   Count: 100 
+```
+
 ## Visualize annotations
 In order to visualize images and corresponding annotations use the script 
 `cvdata/visualize.py` or the corresponding script entry point `cvdata_visualize`. 

setup.py

@@ -8,7 +8,7 @@
 
 setup(
     name="cvdata",
-    version="0.0.6",
+    version="0.0.7",
     author="James Adams",
     author_email="[email protected]",
     description="Tools for creating and manipulating computer vision datasets",

src/cvdata/__init__.py

@@ -0,0 +1,2 @@
+# version of the cvdata package, should match with setup.py
+__version__ = "0.0.7"

src/cvdata/analyze.py

@@ -6,6 +6,7 @@
 from xml.etree import ElementTree
 
 import pandas as pd
+import tensorflow as tf
 
 import cvdata.common
 from cvdata.utils import matching_ids
@@ -138,6 +139,26 @@ def count_labels(
         raise ValueError(f"Unsupported annotation format: \"{annotation_format}\"")
 
 
+# ------------------------------------------------------------------------------
+def count_tfrecord_examples(
+        tfrecords_dir: str,
+) -> int:
+    """
+    Counts the total number of examples in a collection of TFRecord files.
+
+    :param tfrecords_dir: directory that is assumed to contain only TFRecord files
+    :return: the total number of examples in the collection of TFRecord files
+        found in the specified directory
+    """
+
+    count = 0
+    for file_name in os.listdir(tfrecords_dir):
+        tfrecord_path = os.path.join(tfrecords_dir, file_name)
+        count += sum(1 for _ in tf.data.TFRecordDataset(tfrecord_path))
+
+    return count
+
+
 # ------------------------------------------------------------------------------
 def main():
 
@@ -151,7 +172,7 @@ def main():
     )
     args_parser.add_argument(
         "--images",
-        required=True,
+        required=False,
         type=str,
         help="images directory path",
     )
@@ -172,64 +193,71 @@ def main():
     )
     args = vars(args_parser.parse_args())
 
-    # the two dictionaries we'll build for final reporting
-    label_counts = {}
-    label_file_ids = {}
+    if args["format"] == "tfrecord":
 
-    if args["format"] == "openimages":
+        # count and report the examples in the collection of TFRecord files
+        examples_count = count_tfrecord_examples(args["annotations"])
+        print(f"Total number of examples: {examples_count}")
 
-        # read the OpenImages CSV into a pandas DataFrame
-        df_annotations = pd.read_csv(args["annotations"])
-        df_annotations = df_annotations[['ImageID', 'LabelName']]
+    else:
+        # the two dictionaries we'll build for final reporting
+        label_counts = {}
+        label_file_ids = {}
 
-        # TODO get another dataframe from the class descriptions and get the
-        #  readable label names from there to map to the LabelName column
+        if args["format"] == "openimages":
 
-        # whittle it down to only the rows that match to image IDs
-        file_ids = [os.path.splitext(file_name)[0] for file_name in os.listdir(args["images"])]
-        df_annotations = df_annotations[df_annotations["ImageID"].isin(file_ids)]
+            # read the OpenImages CSV into a pandas DataFrame
+            df_annotations = pd.read_csv(args["annotations"])
+            df_annotations = df_annotations[['ImageID', 'LabelName']]
 
-        # TODO populate the label counts and label file IDs dictionaries
+            # TODO get another dataframe from the class descriptions and get the
+            #  readable label names from there to map to the LabelName column
 
-    else:
+            # whittle it down to only the rows that match to image IDs
+            file_ids = [os.path.splitext(file_name)[0] for file_name in os.listdir(args["images"])]
+            df_annotations = df_annotations[df_annotations["ImageID"].isin(file_ids)]
+
+            # TODO populate the label counts and label file IDs dictionaries
 
-        annotation_ext = cvdata.common.FORMAT_EXTENSIONS[args["format"]]
+        else:
 
-        # only annotations matching to the images are considered to be valid
-        file_ids = matching_ids(args["annotations"], args["images"], annotation_ext, ".jpg")
+            annotation_ext = cvdata.common.FORMAT_EXTENSIONS[args["format"]]
 
-        for file_id in file_ids:
-            annotation_file_path = \
-                os.path.join(args["annotations"], file_id + annotation_ext)
+            # only annotations matching to the images are considered to be valid
+            file_ids = matching_ids(args["annotations"], args["images"], annotation_ext, ".jpg")
 
-            # get the images per label count
-            for label, count in count_labels(annotation_file_path, args["format"]).items():
-                if label in label_counts:
-                    label_counts[label] += 1
-                else:
-                    label_counts[label] = 1
+            for file_id in file_ids:
+                annotation_file_path = \
+                    os.path.join(args["annotations"], file_id + annotation_ext)
 
-                # for each label found in the annotation file add this file ID
-                # to the set of file IDs corresponding to the label
-                if args["file_ids"]:
-                    if label in label_file_ids:
-                        # add this file ID to the existing set for the label
-                        label_file_ids[label].add(file_id)
+                # get the images per label count
+                for label, count in count_labels(annotation_file_path, args["format"]).items():
+                    if label in label_counts:
+                        label_counts[label] += 1
                     else:
-                        # first file ID seen for this label so create new set
-                        label_file_ids[label] = {file_id}
-
-    # write the images per label counts
-    for label, count in label_counts.items():
-        print(f"Label: {label}\t\tCount: {count}")
-
-    # write the label ID files, if requested
-    if args["file_ids"]:
-        for label, file_ids_for_label in label_file_ids.items():
-            label_file_ids_path = os.path.join(args["file_ids"], label + ".txt")
-            with open(label_file_ids_path, "w") as label_file_ids_file:
-                for file_id in file_ids_for_label:
-                    label_file_ids_file.write(f"{file_id}\n")
+                        label_counts[label] = 1
+
+                    # for each label found in the annotation file add this file ID
+                    # to the set of file IDs corresponding to the label
+                    if args["file_ids"]:
+                        if label in label_file_ids:
+                            # add this file ID to the existing set for the label
+                            label_file_ids[label].add(file_id)
+                        else:
+                            # first file ID seen for this label so create new set
+                            label_file_ids[label] = {file_id}
+
+        # write the images per label counts
+        for label, count in label_counts.items():
+            print(f"Label: {label}\t\tCount: {count}")
+
+        # write the label ID files, if requested
+        if args["file_ids"]:
+            for label, file_ids_for_label in label_file_ids.items():
+                label_file_ids_path = os.path.join(args["file_ids"], label + ".txt")
+                with open(label_file_ids_path, "w") as label_file_ids_file:
+                    for file_id in file_ids_for_label:
+                        label_file_ids_file.write(f"{file_id}\n")
 
 
 # ------------------------------------------------------------------------------

tests/test_analyze.py

@@ -39,3 +39,20 @@ def test_count_labels(
     assert label_counts["1"] == 2
     assert label_counts["2"] == 1
     assert label_counts["3"] == 1
+
+
+# ------------------------------------------------------------------------------
+@pytest.mark.usefixtures(
+    "data_dir",
+)
+def test_count_tfrecord_examples(
+        data_dir,
+):
+    """
+    Test for the cvdata.analyze.count_tfrecord_examples() function
+
+    :param data_dir: temporary directory into which test files will be loaded
+    """
+    tfrecord_dir = os.path.join(str(data_dir), "tfrecord")
+    example_count = analyze.count_tfrecord_examples(tfrecord_dir)
+    assert example_count == 100