Quantized table based data hiding for concealing data in images

Security to data can be provided using encryption techniques or by hiding it into some cover. Data hiding provides a means for covert type of communication. Although its main purpose is hiding the data, the data can be hidden for personal use or can be used to hide secret messages and send it to the intended recipient. Performance of a data hiding technique based on quantization table is evaluated. An image is divided into 16×16 non-overlapping blocks instead of conventional 8×8 block size. Two-dimensional discrete cosine transform is applied on each block. The obtained frequency coefficients are then used to hide the secret data. Different parameters are chosen to evaluate the quality of image produced after hiding the data. Chosen data can be provided security to the extent upto which the opponent is unable of detecting the secret message by perception. The more the stego-image resembles the carrier image, more secure is the data hiding technique.