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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.
import paddle
import paddle.nn as nn
class DSHSDLoss(nn.Layer):
"""
# DSHSD(IEEE ACCESS 2019)
# paper [Deep Supervised Hashing Based on Stable Distribution](https://ieeexplore.ieee.org/document/8648432/)
# [DSHSD] epoch:70, bit:48, dataset:cifar10-1, MAP:0.809, Best MAP: 0.809
# [DSHSD] epoch:250, bit:48, dataset:nuswide_21, MAP:0.809, Best MAP: 0.815
# [DSHSD] epoch:135, bit:48, dataset:imagenet, MAP:0.647, Best MAP: 0.647
"""
def __init__(self, alpha, multi_label=False):
super(DSHSDLoss, self).__init__()
self.alpha = alpha
self.multi_label = multi_label
def forward(self, input, label):
feature = input["features"]
logits = input["logits"]
dist = paddle.sum(paddle.square(
(paddle.unsqueeze(feature, 1) - paddle.unsqueeze(feature, 0))),
axis=2)
# label to ont-hot
label = paddle.flatten(label)
n_class = logits.shape[1]
label = paddle.nn.functional.one_hot(label, n_class).astype("float32")
s = (paddle.matmul(
label, label, transpose_y=True) == 0).astype("float32")
margin = 2 * feature.shape[1]
Ld = (1 - s) / 2 * dist + s / 2 * (margin - dist).clip(min=0)
Ld = Ld.mean()
if self.multi_label:
# multiple labels classification loss
Lc = (logits - label * logits + (
(1 + (-logits).exp()).log())).sum(axis=1).mean()
else:
# single labels classification loss
Lc = (-paddle.nn.functional.softmax(logits).log() * label).sum(
axis=1).mean()
return {"dshsdloss": Lc + Ld * self.alpha}
class LCDSHLoss(nn.Layer):
"""
# paper [Locality-Constrained Deep Supervised Hashing for Image Retrieval](https://www.ijcai.org/Proceedings/2017/0499.pdf)
# [LCDSH] epoch:145, bit:48, dataset:cifar10-1, MAP:0.798, Best MAP: 0.798
# [LCDSH] epoch:183, bit:48, dataset:nuswide_21, MAP:0.833, Best MAP: 0.834
"""
def __init__(self, n_class, _lambda):
super(LCDSHLoss, self).__init__()
self._lambda = _lambda
self.n_class = n_class
def forward(self, input, label):
feature = input["features"]
# label to ont-hot
label = paddle.flatten(label)
label = paddle.nn.functional.one_hot(label,
self.n_class).astype("float32")
s = 2 * (paddle.matmul(
label, label, transpose_y=True) > 0).astype("float32") - 1
inner_product = paddle.matmul(feature, feature, transpose_y=True) * 0.5
inner_product = inner_product.clip(min=-50, max=50)
L1 = paddle.log(1 + paddle.exp(-s * inner_product)).mean()
b = feature.sign()
inner_product_ = paddle.matmul(b, b, transpose_y=True) * 0.5
sigmoid = paddle.nn.Sigmoid()
L2 = (sigmoid(inner_product) - sigmoid(inner_product_)).pow(2).mean()
return {"lcdshloss": L1 + self._lambda * L2}