Abstract
Information hiding embeds secret data inside a cover format such as text, image, audio or video. The present study examines the feasibility of hiding secret data in a greyscale still image. The proposed method uses the secret data bits content, the difference between the target pixel value and the mean of some neighbour pixel values to determine how many secret data bits should be embedded in the target pixel. The present study first notes some limitations in Chang and Tseng's method and then proposes a generalised method that provides better stego image quality and embedding capacity than that of Chang and Tseng's method.