A Digital Watermarking of Detecting the Image Integrity Based on DWT

The paper designs an image authentication method of semi-fragile watermarking technique based on DWT.The watermark bits are embedded in the average value of the four adjacent wavelet coefficients with quantization since the average value has better stability than single wavelet coefficient.The experiment results show this method is robust to common image process and fragile to malicious attack,i.e.this method can detect the tampered portions.