Table 4 NCC of watermark images extracted from different attacks.

No attack

1

1

1

1

1

1

Salt and pepper noise (m = 0, v = 0.01)

0.9920

0.9968

0.9929

0.9947

0.9969

0.9951

Salt and pepper noise (m = 0, v = 0.05)

0.9337

0.9740

0.9451

0.9508

0.9600

0.9616

Gaussian noise (m = 0, v = 0.01)

0.9772

0.9855

0.9681

0.9812

0.9859

0.9779

Gaussian noise (m = 0, v = 0.05)

0.8380

0.8927

0.8545

0.8746

0.8824

0.9086

Speckle noise (m = 0, v = 0.01)

0.9841

0.9947

0.9919

0.9925

0.9968

0.9981

Speckle noise (m = 0, v = 0.05)

0.8653

0.9643

0.9367

0.9300

0.9540

0.9812

Sharpening

0.9733

0.8996

0.9583

0.9591

0.9429

0.9711

Gaussian filter (3\(\times \)3)

0.9963

0.9599

0.9933

0.9930

0.9896

0.9961

Gaussian filter (5\(\times \)5)

0.9932

0.9347

0.9879

0.9867

0.9806

0.9930

Mean filter (3\(\times \)3)

0.9948

0.9466

0.9905

0.9902

0.9852

0.9946

Mean filter (5\(\times \)5)

0.9818

0.8775

0.9690

0.9645

0.9496

0.9816

Rotation (5\(^\circ \))

0.8984

0.9658

0.9445

0.9315

0.9622

0.9886

Rotation (10\(^\circ \))

0.8445

0.8771

0.8463

0.8412

0.8913

0.9763

Flip vertical

1

1

1

1

1

1

Cropping (10%)

0.9870

0.9975

0.9979

0.9920

0.9936

0.9975

Cropping (20%)

0.9239

0.9664

0.9831

0.9642

0.9155

0.9859

JPEG (QF=90)

0.9988

0.9965

0.9991

0.9999

0.9996

0.9999

JPEG2000 (QF=90)

0.9986

0.9624

0.9954

0.9968

0.9921

0.9984

Gamma correction (gama=0.8)

0.9800

0.9748

0.9883

0.9839

0.9821

0.9860