Per-class saliency maps for M-RCNN (#2301)

* per class sal maps for maskrcnn

* tiling support + test enablement/fix

* enable xai detection e2e tests

Author: Evgeny Tsykunov

otx/algorithms/common/adapters/mmcv/hooks/recording_forward_hook.py

@@ -16,8 +16,9 @@
 from __future__ import annotations
 
 from abc import ABC
-from typing import List, Sequence, Union
+from typing import List, Optional, Sequence, Union
 
+import numpy as np
 import torch
 
 from otx.algorithms.classification import MMCLS_AVAILABLE
@@ -69,10 +70,24 @@ def _recording_forward(
         self, _: torch.nn.Module, x: torch.Tensor, output: torch.Tensor
     ):  # pylint: disable=unused-argument
         tensors = self.func(output)
-        tensors = tensors.detach().cpu().numpy()
-        for tensor in tensors:
+        if isinstance(tensors, torch.Tensor):
+            tensors_np = tensors.detach().cpu().numpy()
+        elif isinstance(tensors, np.ndarray):
+            tensors_np = tensors
+        else:
+            self._torch_to_numpy_from_list(tensors)
+            tensors_np = tensors
+
+        for tensor in tensors_np:
             self._records.append(tensor)
 
+    def _torch_to_numpy_from_list(self, tensor_list: List[Optional[torch.Tensor]]):
+        for i in range(len(tensor_list)):
+            if isinstance(tensor_list[i], list):
+                self._torch_to_numpy_from_list(tensor_list[i])
+            elif isinstance(tensor_list[i], torch.Tensor):
+                tensor_list[i] = tensor_list[i].detach().cpu().numpy()
+
     def __enter__(self) -> BaseRecordingForwardHook:
         """Enter."""
         self._handle = self._module.backbone.register_forward_hook(self._recording_forward)

otx/algorithms/detection/adapters/mmdet/hooks/det_class_probability_map_hook.py

@@ -2,10 +2,13 @@
 # Copyright (C) 2023 Intel Corporation
 # SPDX-License-Identifier: Apache-2.0
 #
-from typing import List, Tuple, Union
+import copy
+from typing import List, Optional, Tuple, Union
 
+import numpy as np
 import torch
 import torch.nn.functional as F
+from mmdet.core import bbox2roi
 
 from otx.algorithms.common.adapters.mmcv.hooks.recording_forward_hook import (
     BaseRecordingForwardHook,
@@ -120,3 +123,127 @@ def forward_single(x, cls_convs, conv_cls):
                     "YOLOXHead, ATSSHead, SSDHead, VFNetHead."
                 )
         return cls_scores
+
+
+class MaskRCNNRecordingForwardHook(BaseRecordingForwardHook):
+    """Saliency map hook for Mask R-CNN model. Only for torch model, does not support OpenVINO IR model.
+
+    Args:
+        module (torch.nn.Module): Mask R-CNN model.
+        input_img_shape (Tuple[int]): Resolution of the model input image.
+        saliency_map_shape (Tuple[int]): Resolution of the output saliency map.
+        max_detections_per_img (int): Upper limit of the number of detections
+            from which soft mask predictions are getting aggregated.
+        normalize (bool): Flag that defines if the output saliency map will be normalized.
+            Although, partial normalization is anyway done by segmentation mask head.
+    """
+
+    def __init__(
+        self,
+        module: torch.nn.Module,
+        input_img_shape: Tuple[int, int],
+        saliency_map_shape: Tuple[int, int] = (224, 224),
+        max_detections_per_img: int = 300,
+        normalize: bool = True,
+    ) -> None:
+        super().__init__(module)
+        self._neck = module.neck if module.with_neck else None
+        self._input_img_shape = input_img_shape
+        self._saliency_map_shape = saliency_map_shape
+        self._max_detections_per_img = max_detections_per_img
+        self._norm_saliency_maps = normalize
+
+    def func(
+        self,
+        feature_map: Union[torch.Tensor, List[torch.Tensor], Tuple[torch.Tensor]],
+        _: int = -1,
+    ) -> List[List[Optional[np.ndarray]]]:
+        """Generate saliency maps by aggregating per-class soft predictions of mask head for all detected boxes.
+
+        :param feature_map: Feature maps from backbone.
+        :return: Class-wise Saliency Maps. One saliency map per each predicted class.
+        """
+        with torch.no_grad():
+            if self._neck is not None:
+                feature_map = self._module.neck(feature_map)
+
+            det_bboxes, det_labels = self._get_detections(feature_map)
+            saliency_maps = self._get_saliency_maps_from_mask_predictions(feature_map, det_bboxes, det_labels)
+            if self._norm_saliency_maps:
+                saliency_maps = self._normalize(saliency_maps)
+        return saliency_maps
+
+    def _get_detections(self, x: torch.Tensor) -> Tuple[List[torch.Tensor], List[torch.Tensor]]:
+        batch_size = x[0].shape[0]
+        img_metas = [
+            {
+                "scale_factor": [1, 1, 1, 1],  # dummy scale_factor, not used
+                "img_shape": self._input_img_shape,
+            }
+        ]
+        img_metas *= batch_size
+        proposals = self._module.rpn_head.simple_test_rpn(x, img_metas)
+        test_cfg = copy.deepcopy(self._module.roi_head.test_cfg)
+        test_cfg["max_per_img"] = self._max_detections_per_img
+        test_cfg["nms"]["iou_threshold"] = 1
+        test_cfg["nms"]["max_num"] = self._max_detections_per_img
+        det_bboxes, det_labels = self._module.roi_head.simple_test_bboxes(
+            x, img_metas, proposals, test_cfg, rescale=False
+        )
+        return det_bboxes, det_labels
+
+    def _get_saliency_maps_from_mask_predictions(
+        self, x: torch.Tensor, det_bboxes: List[torch.Tensor], det_labels: List[torch.Tensor]
+    ) -> List[List[Optional[np.ndarray]]]:
+        _bboxes = [det_bboxes[i][:, :4] for i in range(len(det_bboxes))]
+        mask_rois = bbox2roi(_bboxes)
+        mask_results = self._module.roi_head._mask_forward(x, mask_rois)
+        mask_pred = mask_results["mask_pred"]
+        num_mask_roi_per_img = [len(det_bbox) for det_bbox in det_bboxes]
+        mask_preds = mask_pred.split(num_mask_roi_per_img, 0)
+
+        batch_size = x[0].shape[0]
+
+        scale_x = self._input_img_shape[1] / self._saliency_map_shape[1]
+        scale_y = self._input_img_shape[0] / self._saliency_map_shape[0]
+        scale_factor = torch.FloatTensor((scale_x, scale_y, scale_x, scale_y))
+        test_cfg = self._module.roi_head.test_cfg.copy()
+        test_cfg["mask_thr_binary"] = -1
+
+        saliency_maps = []  # type: List[List[Optional[np.ndarray]]]
+        for i in range(batch_size):
+            saliency_maps.append([])
+            for j in range(self._module.roi_head.mask_head.num_classes):
+                saliency_maps[i].append(None)
+
+        for i in range(batch_size):
+            if det_bboxes[i].shape[0] == 0:
+                continue
+            else:
+                segm_result = self._module.roi_head.mask_head.get_seg_masks(
+                    mask_preds[i],
+                    _bboxes[i],
+                    det_labels[i],
+                    test_cfg,
+                    self._saliency_map_shape,
+                    scale_factor=scale_factor,
+                    rescale=True,
+                )
+                for class_id, segm_res in enumerate(segm_result):
+                    if segm_res:
+                        saliency_maps[i][class_id] = np.mean(np.array(segm_res), axis=0)
+        return saliency_maps
+
+    @staticmethod
+    def _normalize(saliency_maps: List[List[Optional[np.ndarray]]]) -> List[List[Optional[np.ndarray]]]:
+        batch_size = len(saliency_maps)
+        num_classes = len(saliency_maps[0])
+        for i in range(batch_size):
+            for class_id in range(num_classes):
+                per_class_map = saliency_maps[i][class_id]
+                if per_class_map is not None:
+                    max_values = np.max(per_class_map)
+                    per_class_map = 255 * (per_class_map) / (max_values + 1e-12)
+                    per_class_map = per_class_map.astype(np.uint8)
+                    saliency_maps[i][class_id] = per_class_map
+        return saliency_maps

otx/algorithms/detection/adapters/mmdet/models/detectors/custom_maskrcnn_detector.py

@@ -10,7 +10,6 @@
 from mmdet.models.detectors.mask_rcnn import MaskRCNN
 
 from otx.algorithms.common.adapters.mmcv.hooks.recording_forward_hook import (
-    ActivationMapHook,
     FeatureVectorHook,
 )
 from otx.algorithms.common.adapters.mmdeploy.utils import is_mmdeploy_enabled
@@ -99,7 +98,7 @@ def load_state_dict_pre_hook(model, model_classes, chkpt_classes, chkpt_dict, pr
     def custom_mask_rcnn__simple_test(ctx, self, img, img_metas, proposals=None, **kwargs):
         """Function for custom_mask_rcnn__simple_test."""
         assert self.with_bbox, "Bbox head must be implemented."
-        x = backbone_out = self.backbone(img)
+        x = self.backbone(img)
         if self.with_neck:
             x = self.neck(x)
         if proposals is None:
@@ -108,7 +107,8 @@ def custom_mask_rcnn__simple_test(ctx, self, img, img_metas, proposals=None, **k
 
         if ctx.cfg["dump_features"]:
             feature_vector = FeatureVectorHook.func(x)
-            saliency_map = ActivationMapHook.func(backbone_out)
+            # Saliency map will be generated from predictions. Generate dummy saliency_map.
+            saliency_map = torch.empty(1, dtype=torch.uint8)
             return (*out, feature_vector, saliency_map)
 
         return out

otx/algorithms/detection/adapters/mmdet/models/detectors/custom_maskrcnn_tile_optimized.py

@@ -209,7 +209,6 @@ def simple_test(self, img, img_metas, proposals=None, rescale=False, full_res_im
 
     # pylint: disable=ungrouped-imports
     from otx.algorithms.common.adapters.mmcv.hooks.recording_forward_hook import (
-        ActivationMapHook,
         FeatureVectorHook,
     )
 
@@ -327,7 +326,7 @@ def custom_mask_rcnn__simple_test(ctx, self, img, img_metas, proposals=None):
         assert self.with_bbox, "Bbox head must be implemented."
         tile_prob = self.tile_classifier.simple_test(img)
 
-        x = backbone_out = self.backbone(img)
+        x = self.backbone(img)
         if self.with_neck:
             x = self.neck(x)
         if proposals is None:
@@ -336,7 +335,8 @@ def custom_mask_rcnn__simple_test(ctx, self, img, img_metas, proposals=None):
 
         if ctx.cfg["dump_features"]:
             feature_vector = FeatureVectorHook.func(x)
-            saliency_map = ActivationMapHook.func(backbone_out)
+            # Saliency map will be generated from predictions. Generate dummy saliency_map.
+            saliency_map = torch.empty(1, dtype=torch.uint8)
             return (*out, tile_prob, feature_vector, saliency_map)
 
         return (*out, tile_prob)

otx/algorithms/detection/adapters/mmdet/task.py

@@ -61,6 +61,7 @@
 from otx.algorithms.detection.adapters.mmdet.datasets import ImageTilingDataset
 from otx.algorithms.detection.adapters.mmdet.hooks.det_class_probability_map_hook import (
     DetClassProbabilityMapHook,
+    MaskRCNNRecordingForwardHook,
 )
 from otx.algorithms.detection.adapters.mmdet.utils import (
     patch_input_preprocessing,
@@ -397,7 +398,8 @@ def hook(module, inp, outp):
             if raw_model.__class__.__name__ == "NNCFNetwork":
                 raw_model = raw_model.get_nncf_wrapped_model()
             if isinstance(raw_model, TwoStageDetector):
-                saliency_hook = ActivationMapHook(feature_model)
+                height, width, _ = mm_dataset[0]["img_metas"][0].data["img_shape"]
+                saliency_hook = MaskRCNNRecordingForwardHook(feature_model, input_img_shape=(height, width))
             else:
                 saliency_hook = DetClassProbabilityMapHook(feature_model)
 
@@ -515,15 +517,9 @@ def _explain_model(
         explain_parameters: Optional[ExplainParameters] = None,
     ) -> Dict[str, Any]:
         """Main explain function of MMDetectionTask."""
-
         for item in dataset:
             item.subset = Subset.TESTING
 
-        explainer_hook_selector = {
-            "classwisesaliencymap": DetClassProbabilityMapHook,
-            "eigencam": EigenCamHook,
-            "activationmap": ActivationMapHook,
-        }
         self._data_cfg = ConfigDict(
             data=ConfigDict(
                 train=ConfigDict(
@@ -593,6 +589,18 @@ def hook(module, inp, outp):
             model.register_forward_pre_hook(pre_hook)
             model.register_forward_hook(hook)
 
+        if isinstance(feature_model, TwoStageDetector):
+            height, width, _ = mm_dataset[0]["img_metas"][0].data["img_shape"]
+            per_class_xai_algorithm = partial(MaskRCNNRecordingForwardHook, input_img_shape=(width, height))
+        else:
+            per_class_xai_algorithm = DetClassProbabilityMapHook  # type: ignore
+
+        explainer_hook_selector = {
+            "classwisesaliencymap": per_class_xai_algorithm,
+            "eigencam": EigenCamHook,
+            "activationmap": ActivationMapHook,
+        }
+
         explainer = explain_parameters.explainer if explain_parameters else None
         if explainer is not None:
             explainer_hook = explainer_hook_selector.get(explainer.lower(), None)
@@ -602,9 +610,8 @@ def hook(module, inp, outp):
             raise NotImplementedError(f"Explainer algorithm {explainer} not supported!")
         logger.info(f"Explainer algorithm: {explainer}")
 
-        # Class-wise Saliency map for Single-Stage Detector, otherwise use class-ignore saliency map.
         eval_predictions = []
-        with explainer_hook(feature_model) as saliency_hook:
+        with explainer_hook(feature_model) as saliency_hook:  # type: ignore
             for data in dataloader:
                 with torch.no_grad():
                     result = model(return_loss=False, rescale=True, **data)

otx/algorithms/detection/adapters/openvino/model_wrappers/openvino_models.py

@@ -16,6 +16,7 @@
 
 from typing import Dict
 
+import cv2
 import numpy as np
 
 try:
@@ -107,6 +108,85 @@ def postprocess(self, outputs, meta):
 
         return scores, classes, boxes, resized_masks
 
+    def get_saliency_map_from_prediction(self, outputs, meta, num_classes):
+        """Post process function for saliency map of OTX MaskRCNN model."""
+        boxes = outputs[self.output_blob_name["boxes"]]
+        if boxes.shape[0] == 1:
+            boxes = boxes.squeeze(0)
+        scores = boxes[:, 4]
+        boxes = boxes[:, :4]
+        masks = outputs[self.output_blob_name["masks"]]
+        if masks.shape[0] == 1:
+            masks = masks.squeeze(0)
+        classes = outputs[self.output_blob_name["labels"]].astype(np.uint32)
+        if classes.shape[0] == 1:
+            classes = classes.squeeze(0)
+
+        scale_x = meta["resized_shape"][1] / meta["original_shape"][1]
+        scale_y = meta["resized_shape"][0] / meta["original_shape"][0]
+        boxes[:, 0::2] /= scale_x
+        boxes[:, 1::2] /= scale_y
+
+        saliency_maps = [None for _ in range(num_classes)]
+        for box, score, cls, raw_mask in zip(boxes, scores, classes, masks):
+            resized_mask = self._resize_mask(box, raw_mask * score, *meta["original_shape"][:-1])
+            if saliency_maps[cls] is None:
+                saliency_maps[cls] = [resized_mask]
+            else:
+                saliency_maps[cls].append(resized_mask)
+
+        saliency_maps = self._average_and_normalize(saliency_maps, num_classes)
+        return saliency_maps
+
+    def _resize_mask(self, box, raw_cls_mask, im_h, im_w):
+        # Add zero border to prevent upsampling artifacts on segment borders.
+        raw_cls_mask = np.pad(raw_cls_mask, ((1, 1), (1, 1)), "constant", constant_values=0)
+        extended_box = self._expand_box(box, raw_cls_mask.shape[0] / (raw_cls_mask.shape[0] - 2.0)).astype(int)
+        w, h = np.maximum(extended_box[2:] - extended_box[:2] + 1, 1)
+        x0, y0 = np.clip(extended_box[:2], a_min=0, a_max=[im_w, im_h])
+        x1, y1 = np.clip(extended_box[2:] + 1, a_min=0, a_max=[im_w, im_h])
+
+        raw_cls_mask = cv2.resize(raw_cls_mask.astype(np.float32), (w, h))
+        # Put an object mask in an image mask.
+        im_mask = np.zeros((im_h, im_w), dtype=np.float32)
+        im_mask[y0:y1, x0:x1] = raw_cls_mask[
+            (y0 - extended_box[1]) : (y1 - extended_box[1]), (x0 - extended_box[0]) : (x1 - extended_box[0])
+        ]
+        return im_mask
+
+    @staticmethod
+    def _average_and_normalize(saliency_maps, num_classes):
+        for i in range(num_classes):
+            if saliency_maps[i] is not None:
+                saliency_maps[i] = np.array(saliency_maps[i]).mean(0)
+
+        for i in range(num_classes):
+            per_class_map = saliency_maps[i]
+            if per_class_map is not None:
+                max_values = np.max(per_class_map)
+                per_class_map = 255 * (per_class_map) / (max_values + 1e-12)
+                per_class_map = per_class_map.astype(np.uint8)
+                saliency_maps[i] = per_class_map
+        return saliency_maps
+
+    def get_tiling_saliency_map_from_prediction(self, detections, num_classes):
+        """Post process function for saliency map of OTX MaskRCNN model for tiling."""
+        saliency_maps = [None for _ in range(num_classes)]
+
+        # No detection case
+        if isinstance(detections, np.ndarray) and detections.size == 0:
+            return saliency_maps
+
+        classes = [int(cls) - 1 for cls in detections[1]]
+        masks = detections[3]
+        for mask, cls in zip(masks, classes):
+            if saliency_maps[cls] is None:
+                saliency_maps[cls] = [mask]
+            else:
+                saliency_maps[cls].append(mask)
+        saliency_maps = self._average_and_normalize(saliency_maps, num_classes)
+        return saliency_maps
+
     def segm_postprocess(self, *args, **kwargs):
         """Post-process for segmentation masks."""
         return self._segm_postprocess(*args, **kwargs)