Fix reading, writing anno file and saving name of the subset for test subset (open-edge-platform#447)

* fix widerface for test subset

* update Changelog

Author: yasakova-anastasia

CHANGELOG.md

@@ -71,6 +71,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Calling `ProjectDataset.transform()` with a string argument (<https://github.com/openvinotoolkit/datumaro/issues/402>)
 - Attributes casting for CVAT format (<https://github.com/openvinotoolkit/datumaro/pull/403>)
 - Loading of custom project plugins (<https://github.com/openvinotoolkit/datumaro/issues/404>)
+- Reading, writing anno file and saving name of the subset for test subset 
+  (<https://github.com/openvinotoolkit/datumaro/pull/447>)
 
 ### Security
 - Fixed unsafe unpickling in CIFAR import (<https://github.com/openvinotoolkit/datumaro/pull/362>)

datumaro/plugins/widerface_format.py

@@ -34,7 +34,7 @@ def __init__(self, path, subset=None):
 
         if not subset:
             subset = osp.splitext(osp.basename(path))[0]
-            if re.fullmatch(r'wider_face_\S+_bbx_gt', subset):
+            if re.fullmatch(r'wider_face_\S+((_bbx_gt)|(_filelist))', subset):
                 subset = subset.split('_')[2]
         super().__init__(subset=subset)
 
@@ -100,8 +100,10 @@ def _load_items(self, path):
                 image=image_path, annotations=annotations)
 
             try:
-                bbox_count = int(lines[line_idx + 1]) # can be the next image
-            except ValueError:
+                bbox_count = int(lines[line_idx + 1])
+            except ValueError: # can be the next image
+                continue
+            except IndexError: # the file can only contain names of images
                 continue
 
             bbox_lines = lines[line_idx + 2 : line_idx + bbox_count + 2]
@@ -176,7 +178,8 @@ def apply(self):
 
                 bboxes = [a for a in item.annotations
                     if a.type == AnnotationType.bbox]
-                wider_annotation += '%s\n' % len(bboxes)
+                if 0 < len(bboxes):
+                    wider_annotation += '%s\n' % len(bboxes)
                 for bbox in bboxes:
                     wider_bb = ' '.join('%s' % p for p in bbox.get_bbox())
                     wider_annotation += '%s ' % wider_bb