Table 1 Comparison between different loss functions and NWDLOSS.

From: A detection method for small casting defects based on bidirectional feature extraction

CIOU

Weaknesses

Cannot optimize when there is no overlap

Advantages of NWDLOSS

More robust, handles non-overlapping cases and adapts to small object detection

GIoU

Weaknesses

Insensitive to subtle changes

Advantages of NWDLOSS

Performs better in detail capturing and multi-object scenarios

DIoU

Weaknesses

Ignores aspect ratio influence

Advantages of NWDLOSS

Considers both position and shape differences, excelling with complex targets

CIoU

Weaknesses

Not sensitive enough to small objects

Advantages of NWDLOSS

Better suited for small object detection, especially in complex background scenarios

Smooth L1 Loss

Weaknesses

Lacks consideration of box overlap or shape

Advantages of NWDLOSS

Quantifies box differences with Wasserstein distance, ideal for high-precision tasks