Abstract
This research article provides an up-to-date review of spatial-domain steganography. Maintaining the communication as secure as possible when transmitting secret data through any available communication channels is the target of steganography. Currently, image steganography is the most developed field, with several techniques are provided for different image formats. Therefore, the general image steganography including the fundamental concepts, the terminology, and the applications are highlighted in this paper. Further, the paper depicts the essential characteristics between information hiding and cryptography systems. In addition, recent well-known techniques in the spatial-domain steganography, such as LSB and pixel value differencing, are discussed in detail and several comparisons are provided to show the merits and the demerits of the discussed techniques. Furthermore, to aid the steganography researchers in developing efficient spatial-domain embedding techniques, the future research of the spatial-domain steganography is discussed and a set of recommendations are suggested.