Digital Image Quality Evaluation for Spatial Domain Text Steganography

Steganography is one of the techniques that can be used to hide information in any file types such as audio, image, text and video format. The image steganography is about concealing the hidden data into digital images that alter the pixel of the image. This paper will examine how steganography affect the quality of digital images. Two types of images were selected and different capacities of text documents from 4 kB to 45 kB were used as secret messages. The secret message is embedded in the least significant bits of the images and the distortion is measured using peak signal to noise ratio (PSNR). The results show that for small capacity, it is possible to embed in the second most significant bit (LSB 6) while maintaining a good quality image of more than 30 dB, while for a bigger capacity up to 45 kB, embedding in the fourth least significant bit is possible.