Abstrakt

An Improved Edge Adaptive Grid Technique To Authenticate Grey Scale Images

Ishwarya.M, Mary shamala.L

As digital images can be easily altered electronically without any traces left, a security concern is how to verify their integrity and how to detect malicious tampering. The main challenge is to invariantly establish the Edge Adaptive Grid (EAG) and to select the Data Carrying Pixel Locations (DCPLs) because flipping the selected edge pixels for data hiding can interfere with the local image. An improved Edge Adaptive Grid technique is proposed to authenticate grey scale images through Contour Tracer. Contour tracer is used to select the good Data Carrying Pixel Locations associated with L-shape patterns. By maintaining and updating a location status map, a protective mechanism is applied to preserve the context of each DCPL and their corresponding outcomes. Edge adaptive grid techniques is robust against the interferences caused by contours, image noises, and invariantly select the same sequence of data carrying pixel locations in grey scale image. The main advantage of the proposed technique is to keep the size of the cover image as constant as the secret message increased in size and also provides good trade-off between large payload and minimal visual distortion.