International Journal of Computer Applications (0975 – 8887) Volume 154 – No.6, November 2016 37 An Overview of Image Security Techniques Madhu B. Dept. of CSE,Dr.AIT Visvesvaraya Technological Univesrity, Belagavi, Bengaluru India Ganga Holi Dept. of ISE, GAT Visvesvaraya Technological Univesrity, Belagavi, Bengaluru India Srikanta Murthy K. Dept. of CSE, NCET Visvesvaraya Technological Univesrity, Belagavi, Bengaluru India ABSTRACT Today, the world is going to be digitalized in all the ways. Every business units, government and private sectors, research units are using the digital image as transferring mode for every critical data. These images over the internet which will not be secure. Therefore there is a need of image security. Currently, there exists various image security techniques like encryption, watermarking, steganography, etc. This paper discusses the basic image security techniques, the survey of the recent research in the field of image securities like ANN Based Approach, Genetic Algorithm Based Approach, DCT based approach, chaos-based approach, SVD based approach, Steganographic based approach, DWT based approach, visual cryptography based approach, watermarking based approach. The paper provides the future scope of image security. Keywords ANN, Chaos method, DCT, Digital signature, DWT, Genetic algorithm, Image Processing, Image security. 1. INTRODUCTION The image is most widely used communication mode in the different areas like medical area, research area, business area, military area, etc. The important image transfer will takes place over an unsecured Internet network. Thus there is need of proper security for the image to avoid the unauthorized person's access the important information. The advantage of the image is that it covers more multimedia data, and it needs protection [1]. The cryptography is a kind of image security method; that offers the secure transmission and storage method for the image over the internet. Security is the major concern for any system to maintain the integrity, confidentiality and image authenticity. Although the cryptography is the effective method but it also faces the problem in providing the security if the data with grayscale is more [2]. In today's rapid growth of digital communication and electronic data exchange, many of us communicate in cyber space without thinking about the security of the same. The need for exchanging a lot of our private information and secrets in cyberspace. In today's highly computerized and interconnected world, the security of digital image/video has become increasingly more significant in applications such as pay-per-view TV, confidential video conferencing, medical imaging and in industrial or military imaging systems, online transactions, passwords, digital signatures legal’s, etc. These applications need to control access to images and provide the means to verify the integrity of images. In many cases, such information leakage seriously invades personal privacy, example: the malicious spread of photos in personal online albums or patients' medical diagnosis images, and further more it may cause uncountable losses for a company or a nation, e.g. a secret product design for a company or a governmental classified scanned document. However, such convenience could also be used by malicious/unauthorized users to spread the image information rapidly that it may cause uncountable losses for the owner. The encryption for an image is performed to achieve the secure image transmission over the internet. The encryption mechanism is widely used in many areas like image/video transmission, medical image transmission over the insecure network by which the protection against the unauthorized access can be provided. The encryption also has its applicability in military communication and tele-medication. Even the future point of view the encryption has more scope. In the case of image security, where the image has huge and a data properties like high redundancy, bulk capability, and high pixel correlation. The techniques used for encryption can be said as the protection tool for secret data. The encryption is the mechanism where the plain data can be converted to cipher or protected data, and it can read only by decrypting it. The reverse process of encryption is known as decryption that uses an encryption key to decrypt the original data. The data encryption has become the most for all the secret data especially using over the internet, extranets or intranets. The encryption is done by applying the mathematical function which generates a key later the key is used to get the encrypted/ciphered data. Again the mathematical key is used to get the original data. The security management is used to have the user’s authentication, accuracy in data security [4]. The image encryption methods can be classified as value transformation, visual transformation, position permutation algorithm. The common encryption mechanisms are Advanced Encryption Standard (AES), Data Encryption Standard (DES), Triple DES (3DES), Rivest, Shamir and Adelman (RSA) algorithm, and the Scalable encryption algorithm (SEA) and International Data Encryption Algorithm (IDEA). These mechanisms are widely used for images, videos, etc. This paper discusses the survey over the image security techniques. The organized sections of the paper are: Section 2 describes the image processing and applications of image processing. Section 3 describes the security issues and existing image security methods. Section 4 discusses the existing research work in image security from ANN Based Approach, Genetic Algorithm Based Approach, DCT based approach, chaos-based approach, SVD based approach, Steganographic based approach, DWT based approach, visual cryptography based approach, watermarking based approach and Digital Signature based approach. Section 5 discusses the research gap,and illustrates the scope of future research and Section 6 gives the conclusion, Section 7 references. 2. IMAGE APPLICATIONS The recent feasibility of much computer-based technologies has brought multimedia data transformation over the internet. The multimedia data can be included with image or video or audio or graphical objects that contain much important