Capacity Increase for Information Hiding Using Maximum Edged Pixel Value Differencing

Steganography is a transmitting secret messages through innocuous cover carriers in such a manner that the existence of the embedded messages is undetectable. In this Paper, the existing Pixel Value Differencing method is modified so as to increase the embedding capacity for a Digital Image. The proposed method involves examining 2X2 pixel group and finding the direction of max slope. This direction is selected for embedding the secret message. In this case since we are selecting the maximum slope the capacity is increased by as much as 6-7% at the cost of slight increase in MSE and AFCPV. However this does not affect the perceptibility and stego image appears to be as good as the original image.