Distortion in the ISAR image of a target is known to cause by non-uniform rotational motion of the target during image formation. The conventional explanation describes the image distortion as a quadratic phase distortion effect. This quadratic phase distortion effect is significant only when the target image is integrated over an extended period of time; i.e., over a large angular rotation by ...

Introduction: In recent years, the use of magnetic resonance (MR) images in radiation treatment planning has drawn considerable attention. However, although the extent of a tumor can be determined in great detail on MR images, the geometric accuracy of these images is limited by distortions stemming from the inhomogeneity of the static background magnetic field, the nonlineari...

For user convenience, document image processing captured with a digital camera instead of a scanner has been researched. However, existing methods of document image processing are not usable for a perspective document image captured by a digital camera because most of them are designed for the one captured by a scanner. Thus, we have to rectify the perspective of the document image and obtain t...

Many computer vision algorithms rely on the assumption of the pinhole camera model, but lens distortion with off-the-shelf cameras is significant enough to violate this assumption. Many methods for radial distortion estimation have been proposed, but they all have limitations. Robust automatic radial distortion estimation from a single natural image would be extremely useful for some applicatio...

The aim of this article was to study the effect of virtual-reality exposure to situations that are emotionally significant for patients with eating disorders (ED) on the stability of body-image distortion and body-image dissatisfaction. A total of 85 ED patients and 108 non-ED students were randomly exposed to four experimental virtual environments: a kitchen with low-calorie food, a kitchen wi...

The quality of images may be severely degraded in various situations such as imaging during motion, sensing through a diffusive medium, and low signal to noise. Often in such cases, the ideal un-degraded image is not available (no reference exists). This paper overviews past methods that dealt with no-reference (NR) image quality assessment, and then proposes a new NR method for the identificat...

So many skillful techniques are present for protection of confidential images from unauthorized access. Visual cryptography and data hiding are mainly used methods for secure transmission. But main problem of this method is that, during recovering stage exact image that send will not be retrieved. Small amount of distortion may occur. Some areas like medicine, military fields; small distortion ...

OBJECTIVE Preoperative magnetic resonance imaging (MRI), functional MRI, diffusion tensor MRI, magnetic resonance spectroscopy, and positron-emission tomographic scans may be aligned to intraoperative MRI to enhance visualization and navigation during image-guided neurosurgery. However, several effects (both machine- and patient-induced distortions) lead to significant geometric distortion of i...

Correction of radial distortion of the image is a very important process during the calibration of non-metric camera intrinsic parameters. The paper treats the topic of estimation of coefficients and the centre of radial distortion of the image. A new method of coefficients and coordinates of the centre of radial distortion estimation in the image is presented. It is based on the iterative corr...

The paper presents an analysis of the effects of lossy compression algorithms applied to images affected by geometrical distortion. It will be shown that the encoding-decoding process results in a nonhomogeneous image degradation in the geometrically corrected image, due to the different amount of information associated to each pixel. A distortion measure named quadtree distortion map (QDM) abl...