This paper addresses feature-based image watermarking methods for digital contents. Most previous watermarking algorithms suffer from geometric distortion attacks that desynchronize the location of the inserted watermark. In order to synchronize the watermark location, watermark synchronization should be performed. One solution for watermark synchronization is to use image features. This paper ...

Human perception of image distortions has been widely explored in recent years, however, research has not dealt with distortions due to geometric operations. In this paper, we present the results we obtained by means of psychovisual experiments aimed at evaluating the way the human visual system perceives geometric distortions in images. A mathematical model of the geometric distortions is firs...

A main challenge for tasks on panorama lies in the distortion of objects among images. In this work, we propose a Distortion-Aware Monocular Omnidirectional (DAMO) dense depth estimation network to address indoor panoramas with two steps. First, introduce distortion-aware module extract calibrated semantic features from omnidirectional Specifically, exploit deformable convolution adjust its sam...

Visual distortions of perceived lengths, angles, or forms, are generally known as “geometric–optical illusions” (GOI). In the present paper we focus on a class of GOIs where the distortion of a straight line segment (the “target” stimulus) is induced by an array of non-intersecting curvilinear elements (“context” stimulus). Assuming local target– context interactions in a vector field represent...

The majority of computer vision applications assume the pin-hole camera model. However, most optics will introduce some undesirable effects, rendering the assumption of the pin-hole camera model invalid. This is particularly evident in cameras with wide fields-of-view. The aim of distortion correction is, therefore, to transform the distorted view of wide-angle cameras to the pin-hole perspecti...

Due to magnetic field inhomogeneities, EPI images are geometrically distorted, predominantly along the phase-encoding direction. Currently, the distortion is either ignored or compensated manually using a warping function defined through a set of landmarks. We propose an automatic method to unwarp the geometric distortion of EPI images by registering them with corresponding undistorted anatomic...

stract--Magnetic Resonance (MR) images can have sig.qcant geometric distortion due to unintended errors in e magnetic fields used in the scanners. We present a w method to quantify the extent of the misregistration used by magnetic field inhomogeneities in MR images to bpixel accuracy. This method does not require an ex:nal standard such as Computed Tomography (CT) nor es it require that the ge...

This paper presents a new technique for estimating and correcting the geometric distortion produced by common offthe-shelf lenses. The taks of recovering the three most important parameters modeling the lens distortion of a digital camera is formulated as a problem of image warping where the distorted image of a planar calibration plate taken by the camera has to be registered onto the virtual ...