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Image registration for bridge defect growth tracking
Published in Joan-Ramon Casas, Dan M. Frangopol, Jose Turmo, Bridge Safety, Maintenance, Management, Life-Cycle, Resilience and Sustainability, 2022
J. Bush, J. Ninić, G. Thermou, L. Tachtsi, P. Hill, S. Denton, J. Bennetts
Geometric transformations can be expressed as matrices. For 2D images, the 3 ×3 matrix homogeneous representation is typically used. Figure 1 (b)-(e) illustrates the different types of linear transformations. Equations 1 to 4 provide the corresponding matrix representations. Note that such matrices may be multiplied together to combine any number of such transformations, where the resulting combination is known as an affine transformation TRSC=A, which may be represented by a single matrix (Figure 1(f) and Eq. 5).T=10tx01ty001
Copyright Protection of Digital Images of Cultural Heritage
Published in Filippo Stanco, Sebastiano Battiato, Giovanni Gallo, Digital Imaging for Cultural Heritage Preservation, 2017
Filippo Stanco, Sebastiano Battiato, Giovanni Gallo
Translation/Rotation/Uniform Scaling. These simple geometric transformations are commonly used in Computer Graphics to position a 3D model inside a scene. In fact, usually a virtual scene is composed by hundreds of objects that must be rotated, scaled, and translated to obtain the final results. So, this is a basic non-malicious attack to consider. Other more complex geometric transformations such as affine and projective transformations may be used to attack the model, even if they are less common than plain translations, rotations, and isotropic scaling.
Geometric Transformations
Published in Aditi Majumder, M. Gopi, Introduction to Visual Computing, 2018
Geometric transformation, in general, means transforming a geometric entity (e.g. point, line, object) to another. This can happen in any dimension. For example, a 2D image can be transformed to another by translating it or scaling it or applying a unique transformation to each of its pixels. Or, a 3D object like a cube can be transformed into a parallelepiped or sphere. All of these will be considered as geometric transformations. Often a 2D image transformation is also called an image warp.
Calculating the k-Eigenvalue Sensitivity to Typical Geometric Perturbations with the Adjoint-Weighted Method in the Continuous-Energy Reactor Monte Carlo Code RMC
Published in Nuclear Science and Engineering, 2019
Hao Li, Ganglin Yu, Shanfang Huang, Mengfei Zhou, Guanlin Shi, Kan Wang
The geometric factor is the most important term, so this section focuses on that factor. The geometric factors of several typical geometric perturbations are listed in Table IV. The surface types include the planar surface P, spherical surface S, cylindrical surface C/X, and conical surface K/X. The equations and the required parameters of these surface types are listed in Table III. The geometric transformation types include translation along an arbitrary direction, fixed-axis rotation, and uniform isotropic/anisotropic expansion.
A Self-Adaptive Chimp-Driven Modified Deep Learning Framework for Autonomous Vehicles to Obtain Autonomous Object Classification
Published in Electric Power Components and Systems, 2023
Geometric transformations, conversely, involve changing the size, orientation, and position of an image to correct distortions and align it with other images or reference frames. These transformations can include scaling, rotation, translation, and skew correction, among others. Both of these stages are important in the preprocessing of images, as they can improve the quality of the input image and facilitate further analysis and processing. However, the specific techniques used in each stage may vary depending on the nature of the input image and the goals of the processing.