Deep Learning Hash for Wireless Multimedia Image Content Security

Table 2

Summary of notations.

Symbol	Definition
	the gray value of the image pixels
	mean pixels
U	an arbitrary orthogonal matrix and defines in the ZCA whitening
J(W,b)	the quantization loss between the learned binary values and the real values
	a weight attenuation parameter
	set
a, b	two thresholds
D	dimensionality of data points
M, K	number of candidate images
E	the objective function