es in the training dataset as a regularization. This prevents overfitting to the the given target image. The following flags enable the regularization with_prior_preservation, real_prior with prior_loss_weight=1..
The class_prompt should be the category name same as target image. The collected real images are with text captions similar to the class_prompt. The retrieved image are saved in class_data_dir. You can disable real_prior to use genera