captcha_cnn_model.py

# -*- coding: UTF-8 -*-
import torch.nn as nn
import captcha_setting


# CNN Model (2 conv layer)
class CNN(nn.Module):
    def __init__(self):
        super(CNN, self).__init__()
        self.layer1 = nn.Sequential(
            nn.Conv2d(1, 32, kernel_size=3, padding=1),
            nn.BatchNorm2d(32),
            nn.Dropout(0.5),  # drop 50% of the neuron
            nn.ReLU(),
            nn.MaxPool2d(2))
        self.layer2 = nn.Sequential(
            nn.Conv2d(32, 64, kernel_size=3, padding=1),
            nn.BatchNorm2d(64),
            nn.Dropout(0.5),  # drop 50% of the neuron
            nn.ReLU(),
            nn.MaxPool2d(2))
        self.layer3 = nn.Sequential(
            nn.Conv2d(64, 64, kernel_size=3, padding=1),
            nn.BatchNorm2d(64),
            nn.Dropout(0.5),  # drop 50% of the neuron
            nn.ReLU(),
            nn.MaxPool2d(2))
        self.fc = nn.Sequential(
            nn.Linear((captcha_setting.IMAGE_WIDTH//8)*
                      (captcha_setting.IMAGE_HEIGHT//8)*64,1024),
            nn.Dropout(0.25),  # drop 25% of the neuron
            nn.ReLU())
        self.rfc = nn.Sequential(
            nn.Linear(1024, captcha_setting.MAX_CAPTCHA*
                      captcha_setting.ALL_CHAR_SET_LEN),
        )

    def forward(self, x):
        out = self.layer1(x)
        out = self.layer2(out)
        out = self.layer3(out)
        out = out.view(
            out.size(0), -1)
        out = self.fc(out)
        out = self.rfc(out)
        return out