Zero-Watermarking Algorithm for Medical Image Based on VGG19 Deep Convolution Neural Network

Table 8

The images under rotation distortion attack.

	Medical image A	Medical image B	Medical image C	Medical image D	Medical image E
The smallest NC value	0.94054	0.62698	0.5621	0.90682	0.8182
The restored watermarking image
Medical image to be tested