The computational model we propose deals with the measurement of image distortion in such a way that the comparison of a pair of images is performed by matching the corresponding integral features registered within the same xation point which a spatial sensitivity function directs about the images. An integral feature refers to the resultant of recombining the separable representations (color, ...

Image distortion due to field gradient eddy currents can create image artifacts in diffusion-weighted MR images. These images, acquired by measuring the attenuation of NMR signal due to directionally dependent diffusion, have recently been shown to be useful in the diagnosis and assessment of acute stroke and in mapping of tissue structure. This work presents an improvement on the spin-echo (SE...

An image quality investigation in visible spectral imaging was performed. Spectral images were simulated using different number of imaging channels, wavelength steps, and noise levels based on practical spectral imaging systems. A mean opinion score (MOS) was determined from a subjective visual assessment scale experiment for image quality of spectral images rendered to a three-channel display....

This paper presents an optimal subband bit allocation based on a new rate distortion (R-D) model for multi-view image coding with disparity-compensated wavelet lifting. First, the distortion prediction of the reconstructed multi-view image with lifting scheme is presented. A new rate distortion model combining the exponential and power model is developed. Then, the analyzed prediction error and...

Lens distortion causes difficulties for 3D reconstruction, when uncalibrated image sets with weak geometry are used. We show that the largest part of lens distortion, known as the radial distortion, can be estimated along with the center of distortion from the epipolar constraint separately and before bundle adjustment without any calibration rig. The estimate converges as more image pairs are ...

Rate-distortion optimization is the key technique in video coding standards to efficiently determine a set of coding parameters. In the R-D optimization for H.264 I-frame encoder, the distortion (D) is measured as the sum of the squared differences (SSD) between the reconstructed and the original blocks, which is same as MSE. Recently, a new image measurement called Structural Similarity (SSIM)...

The problem of how one stores and transmits a digital image has been a topic of research for more than 40 years and was initially driven by military applications and NASA. The problem, simply stated, is how does one efficiently represent an image in binary form? This is the image compression problem. It is a special case of the source coding problem addressed by Shannon in his landmark paper [1...

Accurate prediction of local distortion visibility thresholds is critical in many image and video processing applications. Existing methods require an accurate modeling of the human visual system, and are derived through pshycophysical experiments with simple, artificial stimuli. These approaches, however, are difficult to generalize to natural images with complex types of distortion. In this p...

The criteria applied on the choice of the compression algorithm is generally based on distortion, compression rate, processing time and hardware limitation. On most cases, the energy expenditure is not considered, however, in some applications, the energy expenditure is a good parameter for choosing the algorithms (E.g. embedded systems that apply the use of batteries). Thus, this article propo...

This paper describes a real-time system for image acquisition, where images are corrected for lensdistortion. Three kinds of distortion can be corrected by the system: barrel, pincushion and pocket-handkerchief. Applications can be found in very high light-efficient systems where lenses with a large numerical aperture produce barrelor pincushion distortion. Examples are medical X-ray systems, w...