data_transforms = {'train':transforms.Compose([transform.RandomRotation(45),#随机旋转,-45到45度之间随机选
transforms.CenterCrop(224),#从中心开始裁剪
transforms.RandomHorizontalFlip(p=0.5),#随机垂直翻转
transforms.ColorJitter(brightness=0.2,contrast=0.1),#参数1为亮度
transforms.RandomGrayscale(p=0.025),#概率转换成灰度率
transforms.ToTensor(),
transforms.Normalize([0.485, 0.456, 0.406], [0.229, 0.224, 0.225])#均值,标准差]),
'valid':transforms.Compose([transforms.Resize(256),
transforms.CenterCrop(224),transforms.ToTensor(),
transforms.Normalize([0.485, 0.456, 0.406], [0.229, 0.224, 0.225])],
}