Research On Large-capacity Visual Security Image Hiding Methods

With the development of Internet technology,users can easily share multimedia data.Digital image is regarded as a good carrier of information exchange because it contains rich information such as color,texture and brightness.However,once the image transmitted in the public channel is illegally tampered,it will cause serious consequences.In order to solve the security problem of the image content in the network environment,researchers initially used encryption technology to rearrange the image data and communicate with the scrambled images,which protected the image content to a certain extent.But the chaotic ciphertext image will cause attackers to suspect.What’s more,the traditional information hiding technology can not meet the needs of large capacity information embedding.In order to achieve more secure image transmission while maintaining high embedding capacity,large capacity image hiding technology emerges as the times require.The main idea of large capacity image hiding is to hide the original image into another carrier image to form a encrypted image with visual security.But there are still some problems in this technology,such as the visual quality of the encrypted image is not high,the original image can not be restored losslessly and so on.So,this paper proposes two improved image hiding methods for large capacity and visual security,and the detailed researches are as follows:(1)A visual security image hiding scheme based on integer wavelet transform and rhombus prediction is proposed.In this method,integer wavelet transform is used to decompose the carrier image.The human visual system is insensitive to the high-frequency components of the image,which can be used to embed information and effectively protect the visual security of the encrypted image.Compared with spatial domain,embedding information in frequency domain is more efficient and robust,so the security of image is further improved.Experimental results show that the quality of the encrypted in this method is better than other methods in recent years.(2)A multi-round visual security image hiding scheme based on reversible image transformation is proposed.The gray level co-occurrence matrix and standard deviation are selected as features to match the original block with the target block.In the multi round transformation,the transformed image generated in the previous round is embedded into the target image again,and then the correlation between the transformed image and the target image is analyzed to adjust the parameters in the transformation process.Experimental results show that the method can effectively improve the matching accuracy between the original image block and the target sub-block,and maintain good visual quality in the case of multi round image transformation.To sum up,this paper takes the image as the carrier,and through the analysis of the experimental results of the proposed scheme,it proves that the high-capacity image hiding method has higher visual quality than the traditional image hiding method.