init

backend/ppocr/utils/iou.py

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+# copyright (c) 2021 PaddlePaddle Authors. All Rights Reserve.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""
+This code is refer from:
+https://github.com/whai362/PSENet/blob/python3/models/loss/iou.py
+"""
+
+import paddle
+
+EPS = 1e-6
+
+
+def iou_single(a, b, mask, n_class):
+    valid = mask == 1
+    a = a.masked_select(valid)
+    b = b.masked_select(valid)
+    miou = []
+    for i in range(n_class):
+        if a.shape == [0] and a.shape == b.shape:
+            inter = paddle.to_tensor(0.0)
+            union = paddle.to_tensor(0.0)
+        else:
+            inter = ((a == i).logical_and(b == i)).astype('float32')
+            union = ((a == i).logical_or(b == i)).astype('float32')
+        miou.append(paddle.sum(inter) / (paddle.sum(union) + EPS))
+    miou = sum(miou) / len(miou)
+    return miou
+
+
+def iou(a, b, mask, n_class=2, reduce=True):
+    batch_size = a.shape[0]
+
+    a = a.reshape([batch_size, -1])
+    b = b.reshape([batch_size, -1])
+    mask = mask.reshape([batch_size, -1])
+
+    iou = paddle.zeros((batch_size, ), dtype='float32')
+    for i in range(batch_size):
+        iou[i] = iou_single(a[i], b[i], mask[i], n_class)
+
+    if reduce:
+        iou = paddle.mean(iou)
+    return iou