为什么深度学习图像预处理都采用mean=[0.485, 0.45

Using the mean and std of Imagenet is a common practice. They are calculated based on millions of images. If you want to train from scratch on your own dataset, you can calculate the new mean and std. Otherwise, using the Imagenet pretrianed model with its own mean and std is recommended.

所以由此看来，是因为imagenet的自然图像的一个统计特征，对于我们特定数据集，如遥感图像或者医学图像不采用该处理方式。