Add duke excluder

Author: ahmdtaha

excluders/duke.py

@@ -0,0 +1,42 @@
+import os
+import re
+
+import numpy as np
+
+
+class Excluder:
+    """
+    In the DukeMTMC-reID evaluation, we need to exclude distractions
+    """
+    def __init__(self, gallery_fids):
+        # Setup a regexp for extracing the PID and camera (CID) form a FID.
+        self.regexp = re.compile('(\S+)_c(\d+)_.*')
+
+        # Parse the gallery_set
+        self.gallery_pids, self.gallery_cids = self._parse(gallery_fids)
+
+    def __call__(self, query_fids):
+        # Extract both the PIDs and CIDs from the query filenames:
+        query_pids, query_cids = self._parse(query_fids)
+
+        # Ignore same pid image within the same camera
+        cid_matches = self.gallery_cids[None] == query_cids[:,None]
+        pid_matches = self.gallery_pids[None] == query_pids[:,None]
+        mask = np.logical_and(cid_matches, pid_matches)
+
+        # Remove all "junk" with the -1 pid.
+        junk_images = np.repeat(self.gallery_pids[None] == '-1', len(query_pids), 0)
+        mask = np.logical_or(mask, junk_images)
+
+        return mask
+
+    def _parse(self, fids):
+        """ Return the PIDs and CIDs extracted from the FIDs. """
+        pids = []
+        cids = []
+        for fid in fids:
+            filename = os.path.splitext(os.path.basename(fid))[0]
+            pid, cid = self.regexp.match(filename).groups()
+            pids.append(pid)
+            cids.append(cid)
+        return np.asarray(pids), np.asarray(cids)