IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE. VOL. II. NO. 6. JUNE 1989 567 Principal Warps: Thin-Plate Splines and the Decomposition of Deformations
Spatial Transformer Networks (2015, methodology): “ all use bilinear sampling, but variants use different transformation functions: an affine transformation (Aff), projective transformation (Proj), and a 16-point thin plate spline transformation (TPS) [2]. The CNN models include two max-pooling layers. All networks have approximately the same number ”
Bird Species Categorization Using Pose Normalized Deep Convolutional Nets (2014, neutral): “The above transformations
Name W (y,w) Solve w∗t p # Pts Translation y = yt +T T = µi−µt |S| ≥ 1
2D Similarity y = sRyt + t R =V diag(1,det(VU>))U>, s = tr(M̄>i RM̄t) tr(M̄>t M̄t) , T = µi− sRµt |S| ≥ 2
2D Affine y = Ayht A = MiM h> t (M h t M h> t ) −1 |S| ≥ 3
Table 1: Computation of warping…”
Learning Video Object Segmentation from Static Images (2016, positive): “To simulate the noise of the previous frame output, during offline training, we generate input masks by deforming the annotations via affine transformation as well as non-rigid deformations via thin-plate splines [4], followed by a coarsening step (dilation morphological operation) to remove details”
Iris Segmentation Using Geodesic Active Contours (2009, methodology): “In the future, the center of the iris and its radius can be coarsely estimated using a faster technique and the GAC may be initialized near the estimated iris boundary to determine the exact shape of the iris.”
Trajectory-Based Skill Learning Using Generalized Cylinders (2018, methodology): “Their proposed trajectory transfer method is based on the classic Thin Plate Splines (TPS) registration algorithm (Bookstein, 1989) extended to 3D Cartesian space, which we also utilize here.”
Active Contours (2000, background): “Splines, common in computer graphics, have also been used in computer vision for some years, for shape-warping (Bookstein, 1988), representing corners and edges in static scenes (Medioni and Yasumoto, 1986; Arbogast and Mohr, 1990) and for shape approximation (Menet et al.”
Large Scale 3D Morphable Models (2017, methodology): “To overcome this limitation, Patel and Smith (2009) proposed to manually annotate the cylindrical face projections with a set of sparse annotations, employing a thin plate splines (TPS) warp (Bookstein 1989) to register the UV images of the meshes into a common reference frame.”
Visualizations in geometric morphometrics: How to read and how to make graphs showing shape changes (2013, methodology): “…shape changes into different geometric components: a component of uniform (or affine) shape change that is the same throughout the entire configuration and a nonuniform component of shape change that is localized to various degrees (Bookstein, 1989, 1991, 1996c; Rohlf and Bookstein, 2003).”
Survey of Medical Image Registration (2013, background): “The „„thin-plate‟‟ spline [52,53] has been used extensively to investigate subtle morphometric variation in schizophrenia [54].”