Patent ID: 7529384

Claim:
A method of extracting hidden data from a received stego-image, comprising the steps of: receiving the stego-image; determining a first number of blocks used to hide data in an original version of the stego-image; computing, by a processor, an optimum block size for extracting the hidden data from the received stego-image based upon said first number of blocks; computing, by said processor, optimal locations in said first number of blocks of said received stego-image for extracting data therefrom; and extracting, by said processor, the hidden data from said optimal locations using said optimum block size, wherein said step of computing an optimum block size further includes the steps of: determining the current pixel dimensions M w ×N w of the received stego-image; calculating a first temporary variable b x *, wherein b x * = M W n x ; calculating a second temporary variable b y *, wherein b y * = N W n y ; calculating a first floor value B x *, wherein B x *=b x * when b x * is an integer and B x *=└b x *┘ when b x * contains a fractional component; calculating a second floor value B y *, wherein B y *=b y * when b y * is an integer and B y *=└b y *┘ when b y * contains a fractional component; and setting dimensions of said optimum block size to B x *×B y *.