Blind Image Watermarking Based on Adaptive Data Spreading in n-Level DWT Subbands

Table 4

Specifications of the existing schemes for comparison.

Items	Proposed	[17]	[16]	[15]	[14]	[9]
# of test images	60	11	1	164	4	3
watermark data	-	32×16	32×32	64×64	64×64	32×32
Q-step	3~10	12	42.5	270~; 24,500	23+p	20
Payload	49,152~163,840; for 32×32 data	6,114	43,520	1,105,920~; 100,352,000	94,208+P	20,480