以下是LeNet网络模型及训练:
from PIL import Image
import cv2
import os
import random
import paddle
import numpy as np
from paddle.nn import Conv2D, MaxPool2D, Linear, Dropout
import paddle.nn.functional as F
DATADIR = 'F:\pythonProject2\yanji\PALM-Training400\PALM-Training400'
# 文件名以N开头的是正常眼底图片,以P开头的是病变眼底图片
file1 = 'N0012.jpg'
file2 = 'P0095.jpg'
# 读取图片
img1 = Image.open(os.path.join(DATADIR, file1))
img1 = np.array(img1)
img2 = Image.open(os.path.join(DATADIR, file2))
img2 = np.array(img2)
# 对读入的图像数据进行预处理
def transform_img(img):
# 将图片尺寸缩放道 224x224
img = cv2.resize(img, (224, 224))
# 读入的图像数据格式是[H, W, C]
# 使用转置操作将其变成[C, H, W]
img = np.transpose(img, (2, 0, 1))
img = img.astype('float32')
# 将数据范围调整到[-1.0, 1.0]之间
img = img / 255.
img = img * 2.0 - 1.0
return img
# 定义训练集数据读取器
def data_loader(datadir, batch_size=10, mode='train'):
# 将datadir目录下的文件列出来,每条文件都要读入
filenames = os.listdir(datadir)
def reader():
if mode == 'train':
# 训练时随机打乱数据顺序
random.shuffle(filenames)
batch_imgs = []
batch_labels = []
for name in filenames:
filepath = os.path.join(datadir, name)
img = cv2.imread(filepath)
img = transform_img(img)
if name[0] == 'H' or name[0] == 'N':
# H开头的文件名表示高度近似,N开头的文件名表示正常视力
# 高度近视和正常视力的样本,都不是病理性的,属于负样本,标签为0
label = 0
elif name[0] == 'P':
# P开头的是病理性近视,属于正样本,标签为1
label = 1
else:
raise ('Not excepted file name')
# 每读取一个样本的数据,就将其放入数据列表中
batch_imgs.append(img)
batch_labels.append(label)
if len(batch_imgs) == batch_size:
# 当数据列表的长度等于batch_size的时候,
# 把这些数据当作一个mini-batch,并作为数据生成器的一个输出
imgs_array = np.array(batch_imgs).astype('float32')
labels_array = np.array(batch_labels).astype('float32').reshape(-1, 1)
yield imgs_array, labels_array
batch_imgs = []
batch_labels = []
if len(batch_imgs) > 0:
# 剩余样本数目不足一个batch_size的数据,一起打包成一个mini-batch
imgs_array = np.array(batch_imgs).astype('float32')
labels_array = np.array(batch_labels).astype('float32').reshape(-1, 1)
yield imgs_array, labels_array
return reader
# 定义验证集数据读取器
def valid_data_loader(datadir, csvfile, batch_size=10, mode='valid'):
# 训练集读取时通过文件名来确定样本标签,验证集则通过csvfile来读取每个图片对应的标签
# 请查看解压后的验证集标签数据,观察csvfile文件里面所包含的内容
# csvfile文件所包含的内容格式如下,每一行代表一个样本,
# 其中第一列是图片id,第二列是文件名,第三列是图片标签,
# 第四列和第五列是Fovea的坐标,与分类任务无关
# ID,imgName,Label,Fovea_X,Fovea_Y
# 1,V0001.jpg,0,1157.74,1019.87
# 2,V0002.jpg,1,1285.82,1080.47
# 打开包含验证集标签的csvfile,并读入其中的内容
filelists = open(csvfile).readlines()
# valid_loader = valid_data_loader(DATADIR2, CSVFILE)
def reader():
batch_imgs = []
batch_labels = []
for line in filelists[1:]:
line = line.strip().split(',')
name = line[1]
label = int(float(line[2]))
# 根据图片文件名加载图片,并对图像数据作预处理
filepath = os.path.join(datadir, name)
img = cv2.imread(filepath)
img = transform_img(img)
# 每读取一个样本的数据,就将其放入数据列表中
batch_imgs.append(img)
batch_labels.append(label)
if len(batch_imgs) == batch_size:
# 当数据列表的长度等于batch_size的时候,
# 把这些数据当作一个mini-batch,并作为数据生成器的一个输出
imgs_array = np.array(batch_imgs).astype('float32')
labels_array = np.array(batch_labels).astype('float32').reshape(-1, 1)
yield imgs_array, labels_array
batch_imgs = []
batch_labels = []
if len(batch_imgs) > 0:
# 剩余样本数目不足一个batch_size的数据,一起打包成一个mini-batch
imgs_array = np.array(batch_imgs).astype('float32')
labels_array = np.array(batch_labels).astype('float32').reshape(-1, 1)
yield imgs_array, labels_array
return reader
train_loader = data_loader(DATADIR,
batch_size=10, mode='train')
data_reader = train_loader()
data = next(data_reader)
# print(data[0].shape, data[1].shape)
eval_loader = data_loader(DATADIR,
batch_size=10, mode='eval')
data_reader = eval_loader()
data = next(data_reader)
# print(data[0].shape, data[1].shape)
DATADIR2 = 'F:\pythonProject2\yanji\PALM-Validation400'
CSVFILE = 'F:\pythonProject2\yanji\PALM-Validation-GT\labels.csv'
# 设置迭代轮数
EPOCH_NUM = 5
# 定义训练过程
def train_pm(model, optimizer):
# 开启0号GPU训练
# use_gpu = True
# paddle.set_device('gpu:0') if use_gpu else paddle.set_device('cpu')
print('start training ... ')
model.train()
# 定义数据读取器,训练数据读取器和验证数据读取器
train_loader = data_loader(DATADIR, batch_size=10, mode='train')
valid_loader = valid_data_loader(DATADIR2, CSVFILE)
for epoch in range(EPOCH_NUM):
for batch_id, data in enumerate(train_loader()):
x_data, y_data = data
img = paddle.to_tensor(x_data)
label = paddle.to_tensor(y_data)
# 运行模型前向计算,得到预测值
logits = model(img)
loss = F.binary_cross_entropy_with_logits(logits, label)
avg_loss = paddle.mean(loss)
if batch_id % 20 == 0:
print("epoch: {}, batch_id: {}, loss is: {:.4f}".format(epoch, batch_id, float(avg_loss.numpy())))
# 反向传播,更新权重,清除梯度
avg_loss.backward()
optimizer.step()
optimizer.clear_grad()
model.eval()
accuracies = []
losses = []
for batch_id, data in enumerate(valid_loader()):
x_data, y_data = data
img = paddle.to_tensor(x_data)
label = paddle.to_tensor(y_data)
# 运行模型前向计算,得到预测值
logits = model(img)
# 二分类,sigmoid计算后的结果以0.5为阈值分两个类别
# 计算sigmoid后的预测概率,进行loss计算
pred = F.sigmoid(logits)
loss = F.binary_cross_entropy_with_logits(logits, label)
# 计算预测概率小于0.5的类别
pred2 = pred * (-1.0) + 1.0
# 得到两个类别的预测概率,并沿第一个维度级联
pred = paddle.concat([pred2, pred], axis=1)
acc = paddle.metric.accuracy(pred, paddle.cast(label, dtype='int64'))
accuracies.append(acc.numpy())
losses.append(loss.numpy())
print("[validation] accuracy/loss: {:.4f}/{:.4f}".format(np.mean(accuracies), np.mean(losses)))
model.train()
paddle.save(model.state_dict(), 'palm.pdparams')
paddle.save(optimizer.state_dict(), 'palm.pdopt')
def evaluation(model, params_file_path):
# 开启0号GPU预估
# use_gpu = True
# paddle.set_device('gpu:0') if use_gpu else paddle.set_device('cpu')
print('start evaluation .......')
# 加载模型参数
model_state_dict = paddle.load(params_file_path)
model.load_dict(model_state_dict)
model.eval()
eval_loader = data_loader(DATADIR,
batch_size=10, mode='eval')
acc_set = []
avg_loss_set = []
for batch_id, data in enumerate(eval_loader()):
x_data, y_data = data
img = paddle.to_tensor(x_data)
label = paddle.to_tensor(y_data)
y_data = y_data.astype(np.int64)
label_64 = paddle.to_tensor(y_data)
# 计算预测和精度
prediction, acc = model(img, label_64)
# 计算损失函数值
loss = F.binary_cross_entropy_with_logits(prediction, label)
avg_loss = paddle.mean(loss)
acc_set.append(float(acc.numpy()))
avg_loss_set.append(float(avg_loss.numpy()))
# 求平均精度
acc_val_mean = np.array(acc_set).mean()
avg_loss_val_mean = np.array(avg_loss_set).mean()
print('loss={:.4f}, acc={:.4f}'.format(avg_loss_val_mean, acc_val_mean))
# 定义 LeNet 网络结构
class LeNet(paddle.nn.Layer):
def __init__(self, num_classes=1):
super(LeNet, self).__init__()
# 创建卷积和池化层块,每个卷积层使用Sigmoid激活函数,后面跟着一个2x2的池化
self.conv1 = Conv2D(in_channels=3, out_channels=6, kernel_size=5)
self.max_pool1 = MaxPool2D(kernel_size=2, stride=2)
self.conv2 = Conv2D(in_channels=6, out_channels=16, kernel_size=5)
self.max_pool2 = MaxPool2D(kernel_size=2, stride=2)
# 创建第3个卷积层
self.conv3 = Conv2D(in_channels=16, out_channels=120, kernel_size=4)
# 创建全连接层,第一个全连接层的输出神经元个数为64
self.fc1 = Linear(in_features=300000, out_features=64)
# 第二个全连接层输出神经元个数为分类标签的类别数
self.fc2 = Linear(in_features=64, out_features=num_classes)
# 网络的前向计算过程
def forward(self, x, label=None):
x = self.conv1(x)
x = F.sigmoid(x)
x = self.max_pool1(x)
x = self.conv2(x)
x = F.sigmoid(x)
x = self.max_pool2(x)
x = self.conv3(x)
x = F.sigmoid(x)
x = paddle.reshape(x, [x.shape[0], -1])
x = self.fc1(x)
x = F.sigmoid(x)
x = self.fc2(x)
if label is not None:
acc = paddle.metric.accuracy(input=x, label=label)
return x, acc
else:
return x
# 创建模型
model = LeNet(num_classes=1)
# # 启动训练过程
# opt = paddle.optimizer.Momentum(learning_rate=0.001, momentum=0.9, parameters=model.parameters())
# train_pm(model, optimizer=opt)
# evaluation(model, params_file_path="palm.pdparams")
求模型测试代码