docs: update install instruction (PaddlePaddle#88)

* docs: update install instruction

1. paddlepaddle2.0.0rc instruction can be found from main page
2. only two steps, install paddlepaddle and paddlegan, other than 3step

* docs: update en install
* feat: add dcgan
* reform: debug with mnist datset
validate performance with different options, and original structure and setting

configs/dcgan_mnist.yaml

@@ -0,0 +1,70 @@
+epochs: 200
+output_dir: output_dir
+
+model:
+  name: DCGANModel
+  generator:
+    name: DCGenerator
+    norm_type: batch
+    input_nz: 100
+    input_nc: 1
+    output_nc: 1
+    ngf: 64
+  discriminator:
+    name: DCDiscriminator
+    norm_type: batch
+    ndf: 64
+    input_nc: 1
+  gan_mode: vanilla #wgangp
+
+dataset:
+  train:
+    name: SingleDataset
+    dataroot: data/mnist/train
+    phase: train
+    max_dataset_size: inf
+    direction: AtoB
+    input_nc: 1
+    output_nc: 1
+    batch_size: 128
+    serial_batches: False
+    transforms:
+      - name: Resize
+        size: [64, 64]
+        interpolation: 'bicubic' #cv2.INTER_CUBIC
+      - name: Transpose
+      - name: Normalize
+        mean: [127.5, 127.5, 127.5]
+        std: [127.5, 127.5, 127.5]
+  test:
+    name: SingleDataset
+    dataroot: data/mnist/test
+    max_dataset_size: inf
+    input_nc: 1
+    output_nc: 1
+    serial_batches: False
+    transforms:
+      - name: Resize
+        size: [64, 64]
+        interpolation: 'bicubic' #cv2.INTER_CUBIC 
+      - name: Transpose
+      - name: Normalize
+        mean: [127.5, 127.5, 127.5]
+        std: [127.5, 127.5, 127.5]
+
+optimizer:
+  name: Adam
+  beta1: 0.5
+
+lr_scheduler:
+  name: linear
+  learning_rate: 0.00002
+  start_epoch: 100
+  decay_epochs: 100
+
+log_config:
+  interval: 100
+  visiual_interval: 500
+
+snapshot_config:
+  interval: 5

docs/en_US/install.md

@@ -24,8 +24,11 @@ Note: command above will install paddle with cuda10.2，if your installed cuda i
 </code></pre> </details> </td> <td align="left"><details><summary> install </summary><pre><code>python -m pip install https://paddle-wheel.bj.bcebos.com/2.0.0-rc0-gpu-cuda9-cudnn7-mkl%2Fpaddlepaddle_gpu-2.0.0rc0.post90-cp36-cp36m-linux_x86_64.whl
 </code></pre> </details> </td> </tr></tbody></table>
 
+Visit home page of [paddlepaddle](https://www.paddlepaddle.org.cn/install/quick) for support of other systems, such as Windows10.
 
-### 2. Install through pip
+### 2. Install paddleGAN 
+
+#### 2.1 Install through pip
 
 ```
 # only support Python3
@@ -39,7 +42,7 @@ git clone /~https://github.com/PaddlePaddle/PaddleGAN
 cd PaddleGAN
 ```
 
-### 3. Install through source code
+#### 2.2 Install through source code
 
 ```
 git clone /~https://github.com/PaddlePaddle/PaddleGAN

docs/zh_CN/install.md

@@ -23,8 +23,11 @@ pip install -U paddlepaddle-gpu==2.0.0rc0
 </code></pre> </details> </td> <td align="left"><details><summary> install </summary><pre><code>python -m pip install https://paddle-wheel.bj.bcebos.com/2.0.0-rc0-gpu-cuda9-cudnn7-mkl%2Fpaddlepaddle_gpu-2.0.0rc0.post90-cp36-cp36m-linux_x86_64.whl
 </code></pre> </details> </td> </tr></tbody></table>
 
-### 2. 通过Pip安装
+支持更多系统的安装教程请前往[paddlepaddle官网](https://www.paddlepaddle.org.cn/install/quick)
 
+### 2. 安装PaddleGAN
+
+##### 2.1 通过Pip安裝
 ```
 # only support Python3
 python3 -m pip install --upgrade ppgan
@@ -37,7 +40,7 @@ git clone /~https://github.com/PaddlePaddle/PaddleGAN
 cd PaddleGAN
 ```
 
-### 3. 通过源码安装PaddleGAN
+##### 2.2通过源码安装
 
 ```
 git clone /~https://github.com/PaddlePaddle/PaddleGAN

ppgan/models/__init__.py

@@ -18,3 +18,4 @@
 from .srgan_model import SRGANModel
 from .sr_model import SRModel
 from .makeup_model import MakeupModel
+from .dc_gan_model import DCGANModel

ppgan/models/dc_gan_model.py

@@ -0,0 +1,136 @@
+#   Copyright (c) 2020 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
+from .base_model import BaseModel
+
+from .builder import MODELS
+from .generators.builder import build_generator
+from .discriminators.builder import build_discriminator
+from .losses import GANLoss
+
+from ..solver import build_optimizer
+from ..modules.init import init_weights
+
+
+@MODELS.register()
+class DCGANModel(BaseModel):
+    """ This class implements the DCGAN model, for learning a distribution from input images.
+
+    The model training requires dataset.
+    By default, it uses a '--netG DCGenerator' generator,
+    a '--netD DCDiscriminator' discriminator,
+    and a vanilla GAN loss (the cross-entropy objective used in the orignal GAN paper).
+
+    DCGAN paper: https://arxiv.org/pdf/1511.06434
+    """
+    def __init__(self, cfg):
+        """Initialize the DCGAN class.
+
+        Parameters:
+            opt (config dict)-- stores all the experiment flags; needs to be a subclass of Dict
+        """
+        super(DCGANModel, self).__init__(cfg)
+        # define networks (both generator and discriminator)
+        self.nets['netG'] = build_generator(cfg.model.generator)
+        init_weights(self.nets['netG'])
+        self.cfg = cfg
+        if self.is_train:
+            self.nets['netD'] = build_discriminator(cfg.model.discriminator)
+            init_weights(self.nets['netD'])
+
+        if self.is_train:
+            self.losses = {}
+            # define loss functions
+            self.criterionGAN = GANLoss(cfg.model.gan_mode)
+
+            # build optimizers
+            self.build_lr_scheduler()
+            self.optimizers['optimizer_G'] = build_optimizer(
+                cfg.optimizer,
+                self.lr_scheduler,
+                parameter_list=self.nets['netG'].parameters())
+            self.optimizers['optimizer_D'] = build_optimizer(
+                cfg.optimizer,
+                self.lr_scheduler,
+                parameter_list=self.nets['netD'].parameters())
+
+    def set_input(self, input):
+        """Unpack input data from the dataloader and perform necessary pre-processing steps.
+
+        Parameters:
+            input (dict): include the data itself and its metadata information.
+        """
+        # get 1-channel gray image, or 3-channel color image
+        self.real = paddle.to_tensor(input['A'][:,0:self.cfg.model.generator.input_nc,:,:])
+        self.image_paths = input['A_paths']
+
+    def forward(self):
+        """Run forward pass; called by both functions <optimize_parameters> and <test>."""
+
+        # generate random noise and fake image
+        self.z = paddle.rand(shape=(self.real.shape[0],self.cfg.model.generator.input_nz,1,1))
+        self.fake = self.nets['netG'](self.z) 
+
+        # put items to visual dict
+        self.visual_items['real'] = self.real
+        self.visual_items['fake'] = self.fake
+
+    def backward_D(self):
+        """Calculate GAN loss for the discriminator"""
+        # Fake; stop backprop to the generator by detaching fake
+        pred_fake = self.nets['netD'](self.fake.detach())
+        self.loss_D_fake = self.criterionGAN(pred_fake, False)
+
+        pred_real = self.nets['netD'](self.real)
+        self.loss_D_real = self.criterionGAN(pred_real, True)
+
+        # combine loss and calculate gradients
+        self.loss_D = (self.loss_D_fake + self.loss_D_real) * 0.5
+
+        self.loss_D.backward()
+
+        self.losses['D_fake_loss'] = self.loss_D_fake
+        self.losses['D_real_loss'] = self.loss_D_real
+
+    def backward_G(self):
+        """Calculate GAN loss for the generator"""
+        # G(A) should fake the discriminator
+        pred_fake = self.nets['netD'](self.fake)
+        self.loss_G_GAN = self.criterionGAN(pred_fake, True)
+
+        # combine loss and calculate gradients
+        self.loss_G = self.loss_G_GAN
+
+        self.loss_G.backward()
+
+        self.losses['G_adv_loss'] = self.loss_G_GAN
+
+    def optimize_parameters(self):
+        # compute fake images: G(A)
+        self.forward()
+
+        #update D
+        self.set_requires_grad(self.nets['netD'], True)
+        self.set_requires_grad(self.nets['netG'], False)
+        self.optimizers['optimizer_D'].clear_grad()
+        self.backward_D()
+        self.optimizers['optimizer_D'].step()
+
+        # update G
+        self.set_requires_grad(self.nets['netD'], False)
+        self.set_requires_grad(self.nets['netG'], True)
+        self.optimizers['optimizer_G'].clear_grad()
+        self.backward_G()
+        self.optimizers['optimizer_G'].step()

ppgan/models/discriminators/__init__.py

@@ -13,3 +13,4 @@
 # limitations under the License.
 
 from .nlayers import NLayerDiscriminator
+from .dcdiscriminator import DCDiscriminator

ppgan/models/discriminators/dcdiscriminator.py

@@ -0,0 +1,103 @@
+# Copyright (c) 2020 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 functools
+import numpy as np
+import paddle.nn as nn
+import paddle.nn.functional as F
+
+from paddle.nn import BatchNorm2D
+from ...modules.norm import build_norm_layer
+
+from .builder import DISCRIMINATORS
+
+
+@DISCRIMINATORS.register()
+class DCDiscriminator(nn.Layer):
+    """Defines a DCGAN discriminator"""
+    def __init__(self, input_nc, ndf=64, norm_type='instance'):
+        """Construct a DCGAN discriminator
+
+        Parameters:
+            input_nc (int)  -- the number of channels in input images
+            ndf (int)       -- the number of filters in the last conv layer
+            norm_type (str)      -- normalization layer type
+        """
+        super(DCDiscriminator, self).__init__()
+        norm_layer = build_norm_layer(norm_type)
+        if type(
+                norm_layer
+        ) == functools.partial:  # no need to use bias as BatchNorm2d has affine parameters
+            use_bias = norm_layer.func == nn.BatchNorm2D
+        else:
+            use_bias = norm_layer == nn.BatchNorm2D
+
+        kw = 4
+        padw = 1
+
+        sequence = [
+                nn.Conv2D(input_nc,
+                          ndf,
+                          kernel_size=kw,
+                          stride=2,
+                          padding=padw,
+                          bias_attr=use_bias),
+                nn.LeakyReLU(0.2)
+            ]
+
+        nf_mult = 1
+        nf_mult_prev = 1
+        n_downsampling = 4
+
+        for n in range(1, n_downsampling):  # gradually increase the number of filters
+            nf_mult_prev = nf_mult
+            nf_mult = min(2**n, 8)
+            if norm_type == 'batch':
+                sequence += [
+                    nn.Conv2D(ndf * nf_mult_prev,
+                                  ndf * nf_mult,
+                                  kernel_size=kw,
+                                  stride=2,
+                                  padding=padw),
+                    BatchNorm2D(ndf * nf_mult),
+                    nn.LeakyReLU(0.2)
+                ]
+            else:
+                sequence += [
+                    nn.Conv2D(ndf * nf_mult_prev,
+                              ndf * nf_mult,
+                              kernel_size=kw,
+                              stride=2,
+                              padding=padw,
+                              bias_attr=use_bias),
+                    norm_layer(ndf * nf_mult),
+                    nn.LeakyReLU(0.2)
+                ]
+
+        nf_mult_prev = nf_mult
+
+        sequence += [
+                nn.Conv2D(ndf * nf_mult_prev,
+                          1,
+                          kernel_size=kw,
+                          stride=1,
+                          padding=0)
+            ]  # output 1 channel prediction map
+
+        self.model = nn.Sequential(*sequence)
+
+    def forward(self, input):
+        """Standard forward."""
+        return self.model(input)

ppgan/models/generators/__init__.py

@@ -16,3 +16,4 @@
 from .unet import UnetGenerator
 from .rrdb_net import RRDBNet
 from .makeup import GeneratorPSGANAttention
+from .dcgenerator import DCGenerator