3.4.1. Reconstruction Loss

Reconstruction loss is a straightforward method that can measure pixel-wise differences between the predicted region and the associated surroundings. We prefer to adopt L1 distance to calculate the reconstruction loss rather than L2 distance as the latter will produce images with much blurriness [29]. We will verify this conclusion in the ablation studies. In our two-stage model, the overall reconstruction losses can be expressed as follows:

The pixel reconstruction loss can guarantee the consistency of contents in the generated area and the background area. Moreover, this function can benefit to reconstruct initial structural information while some high-frequency details will be ignored.