Detection of Stego Images with Adaptively Embedded Data by Component Analysis Methods

Ensuring the effective protection of personal and corporate sensitive data is topical task today. The special interest is taken at sensitive data leakage prevention during files transmission in communication systems. In most cases, these leakages are conducted by usage of advance adaptive steganographic methods. These methods are aimed at minimizing distortions of cover files, such as digital images, during data hiding that negatively impact on detection accuracy of formed stego images. For overcoming this shortcoming, it was proposed to pre-process (calibrate) analyzed images for increasing stego- to-cover ratio. The modern paradigm of image calibration is based on usage of enormous set of high-pass filters. However, selection of filter(s) that maximizes the probability of stego images detection is non-trivial task, especially in case of limited a prior knowledge about embedding methods. For solving this task, we proposed to use component analysis methods for image calibration, namely principal components analysis. Results of comparative analysis of novel maxSRMd2 cover rich model and proposed solution showed that principal component analysis allows increasing detection accuracy up to 1.5% even in the most difficult cases (low cover image payload and absence of cover- stego images pairs in training set).

Two-Dimensional Analysis of Digital Images through Vector Graphic Editors in Dentistry: New Calibration and Analysis Protocol Based on a Scoping Review

This review was carried out to analyse the functions of three Vector Graphic Editor applications (VGEs) applicable to clinical or research practice, and through this we propose a two-dimensional image analysis protocol in a VGE. We adapted the review method from the PRISMA-ScR protocol. Pubmed, Embase, Web of Science, and Scopus were searched until June 2020 with the following keywords: Vector Graphics Editor, Vector Graphics Editor Dentistry, Adobe Illustrator, Adobe Illustrator Dentistry, Coreldraw, Coreldraw Dentistry, Inkscape, Inkscape Dentistry. The publications found described the functions of the following VGEs: Adobe Illustrator, CorelDRAW, and Inkscape. The possibility of replicating the procedures to perform the VGE functions was analysed using each study’s data. The search yielded 1032 publications. After the selection, 21 articles met the eligibility criteria. They described eight VGE functions: line tracing, landmarks tracing, linear measurement recording, angular measurement recording, image calibration, image overlay, file transfer, and vector graphics development. The features offered by the VGEs bring great precision and objectivity to two-dimensional image analysis. The image analysis and editing procedures are currently not protocolised. Thus, a protocol for image calibration and measurement recording is proposed in order to guarantee the protocol’s replication.

Evaluation of Solving Methods for the Fundamental Matrix Computation

Solving the fundamental matrix is a key step in many image calibration and 3D reconstruction systems. The goal of this paper is to study the performance of non-linear solvers for estimating the fundamental matrix in projector-camera calibration. To prevent measurements errors from distorting our understanding, synthetic data are created from ground-truth camera and projector parameters and then used for the assessment of four nonlinear solving strategies.