Spatially variant defocus blur map estimation and deblurring from a single image

The security of digital medical images has attracted much attention recently, especially when these images are sent through the communication networks. An image encryption technique tries to convert an image to another image that is hard to understand. In this communication, we propose an encryption method for gray scale medical images based on the features of genetic algorithms. Performance analysis show that the proposed scheme has good statistical character, key sensitivity and can resist brute-force attack, differential attack, plaintext attack and entropy attack efficiently.

Medical image protection using genetic algorithm operations

Visual secret sharing (VSS), also called visual cryptography, allows a secret image to be divided into several shares and the secret image can only be recovered through the collaboration of the shares. Due to high security and low computational complexity, VSS has been widely used in secure communications. In this paper, we propose the first turtle shell (TS)-based VSS scheme that shares the secret information into two meaningful shares. Firstly, a TS reference matrix is established. Then, secret information is hidden in a cover image to construct two meaningful shares with the help of TS reference matrix. The hidden secret information can be extracted without distortion if both shares are gathered and the cover image can be correctly restored by solving the location conflict problem. Moreover, an invalid share can easily be detected by the proposed scheme. Experimental results indicate that the proposed scheme provides excellent visual quality and is superior to state-of-the-art VSS schemes.

A turtle shell-based visual secret sharing scheme with reversibility and authentication

In recent years, especially when these images are transmitted via a network, digital image security has attracted attention. The 2D barcode is designed to encrypt patient information. In this paper, we proposed a grayscale medical image encryption technology based on the characteristics of genetic algorithm (GAS) using LSB technology. The patient information will be converting into 2D barcode and after that, the original image is embedded with 2D barcode using LSB technique. The LSB technique is more suitable for medical imaging. The resulting image is subjected to a genetic algorithm. In this purpose design, we combined the genetic with LSB technique to make the patient image and its information more secured.

A Pixel-Based Digital Medical Images Protection Using Genetic Algorithm with LSB Watermark Technique

Random-grid based progressive visual secret sharing scheme with adaptive priority

Friendly progressive random-grid-based visual secret sharing with adaptive contrast

Multi-factor cheating prevention in visual secret sharing by hybrid codebooks

In an image secret sharing scheme (ISSS), two main categories are discussed. One is the polynomial-style image secret sharing scheme (PISSS), and the other is the visual secret sharing (VSS). It is interesting to combine the main properties of these two schemes. When the encoded secret images are received, we can decode them by combining these two schemes’ properties, utilizing the VSS property to seek the secret immediately by human visual system (HVS) and the PISSS property to recover the secret perfectly with a decoding machine. This paper combines PISSS and random grids-based VSS to remove all the drawbacks existing in the previous works including 1) distortion by compressing a secret image, 2) non-perfect reconstructed image, 3) distortion of pixel expansion, and 4) size-reduced halftone image. The experimental results demonstrate the proposed scheme does work well.

On the design of a two-decoding-option image secret sharing scheme

Visual secret sharing (VSS) schemes are classified into two categories-visual cryptography-based (VC) and random grid-based (RG)-with the purpose of encoding a secret into several meaningless shared images that can be superimposed to reveal the secret again. VC-based VSS suffers from the problems of pixel expansion and difficulty in alignment. Although the first problem has been solved by RG-based VSS, the latter remains. This paper proposes a new deviation-tolerant RG-based VSS method without pixel expansion. To demonstrate its feasibility, experiments are conducted to show that the reconstructed secret image is still recognizable visually when one shared image shifts by one or more pixels. Compared with related works, the proposed scheme not only has higher misalignment tolerance but also avoids the significant drawbacks in the related work. Recover the secret image without the need to align the shares precisely.A deviation-tolerant RG-based VSS method without pixel expansion.The proposed scheme has higher misalignment tolerance.

On the difficulty of aligning VSS random grids

With the advance in the medical image from photographic i¬lm (analogy) to digital i¬le, how to avoid medical image modii¬ed by malice and hide the patient's information into their medical image has become the promising research issue It is difi¬cult to embed the information of patient to medical images because most pixels of this kind of images are close to black or white In this paper, an effective method based on singular value decomposition (SVD) is presented to hide the patient's information into medical images which can be used to protect and authenticate their images, called Non-ROI Hidding Algorithm (NRHA) More precisely, the SVD is i¬rst employed to i¬nd the features of medical image, and then the information of patient will be hidden in the non-ROI area of the image To evaluate the performance of the proposed algorithm, we use it to hide the information of patient to several digital medical images Our experimental results indicate that the proposed method can be used to avoid malicious attacks because it provides an effective way to distinguish good images from malicious ones As a result, the patient information can be protected by using the proposed method

Chih-Hung Lin

Papers

Friendly progressive random-grid-based visual secret sharing with adaptive contrast

Multi-factor cheating prevention in visual secret sharing by hybrid codebooks

On the design of a two-decoding-option image secret sharing scheme

On the difficulty of aligning VSS random grids

An Efficient Algorithm for Protecting and Authenticating Medical Image