From 3d826b691937140e52c421ef7de7d05b276cc150 Mon Sep 17 00:00:00 2001
From: Mihai Dusmanu <mihai.dusmanu@gmail.com>
Date: Tue, 12 Jul 2022 11:44:12 +0200
Subject: [PATCH 1/2] Initial version.

---
 hloc/extract_features.py       | 15 +++++++++++++++
 hloc/extractors/msretrieval.py | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+)
 create mode 100644 hloc/extractors/msretrieval.py

diff --git a/hloc/extract_features.py b/hloc/extract_features.py
index 1713f320..19fd237d 100644
--- a/hloc/extract_features.py
+++ b/hloc/extract_features.py
@@ -123,6 +123,21 @@
         'output': 'global-feats-openibl',
         'model': {'name': 'openibl'},
         'preprocessing': {'resize_max': 1024},
+    },
+    'dir-ms': {
+        'output': 'global-feats-dir-ms',
+        'model': {'name': 'msretrieval', 'backbone': {'name': 'dir'}},
+        'preprocessing': {'resize_max': 1024},
+    },
+    'netvlad-ms': {
+        'output': 'global-feats-netvlad-ms',
+        'model': {'name': 'msretrieval', 'backbone': {'name': 'netvlad'}},
+        'preprocessing': {'resize_max': 1024},
+    },
+    'openibl-ms': {
+        'output': 'global-feats-openibl-ms',
+        'model': {'name': 'msretrieval', 'backbone': {'name': 'openibl'}},
+        'preprocessing': {'resize_max': 1024},
     }
 }
 
diff --git a/hloc/extractors/msretrieval.py b/hloc/extractors/msretrieval.py
new file mode 100644
index 00000000..cba31604
--- /dev/null
+++ b/hloc/extractors/msretrieval.py
@@ -0,0 +1,32 @@
+import kornia
+import torch
+import torch.nn.functional as F
+
+from ..utils.base_model import BaseModel, dynamic_load
+from .. import extractors
+
+
+class MultiscaleRetrieval(BaseModel):
+    default_conf = {
+        'scales': [1.41, 1.0, 0.71]
+    }
+
+    def _init(self, conf):
+        self.scales = conf['scales']
+        assert 'backbone' in conf
+        Backbone = dynamic_load(extractors, conf['backbone']['name'])
+        self.backbone = Backbone(conf['backbone'])
+    
+    def _forward(self, data):
+        input_image = data['image']
+
+        global_descs = []
+        for scale in self.scales:
+            image = kornia.geometry.rescale(input_image, (scale, scale), antialias=True)
+            global_descs.append(self.backbone({'image': image})['global_descriptor'])
+        global_desc = torch.mean(torch.stack(global_descs, dim=0), dim=0)
+        global_desc = F.normalize(global_desc, dim=1)
+
+        return {
+            'global_descriptor': global_desc
+        }
\ No newline at end of file

From 07009d4d6b61eb82cbe5ddbb4cce26488dc5f034 Mon Sep 17 00:00:00 2001
From: Mihai Dusmanu <mihai.dusmanu@gmail.com>
Date: Tue, 12 Jul 2022 11:47:14 +0200
Subject: [PATCH 2/2] fix.

---
 hloc/extractors/msretrieval.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hloc/extractors/msretrieval.py b/hloc/extractors/msretrieval.py
index cba31604..7f640329 100644
--- a/hloc/extractors/msretrieval.py
+++ b/hloc/extractors/msretrieval.py
@@ -29,4 +29,4 @@ def _forward(self, data):
 
         return {
             'global_descriptor': global_desc
-        }
\ No newline at end of file
+        }