The Photo CD system, originally aimed at consumers, has also been used by cultural institutions to store digital images from scanned photographic film, prints, and documents. With improvements in technology and anticipated adoption of new digital image standards, e.g., JPEG 2000, retention of image fidelity during migration of digital collections is often a concern. In a previous report (Archiv...

In this paper, we present a unifying framework for retinex that is able to reproduce many of the existing retinex implementations within a single model. The fundamental assumption, as shared with many retinex models, is that the observed image is a multiplication between the illumination and the true underlying reflectance of the object. Starting from Morel’s 2010 PDE model for retinex, where i...

Total Variation (TV) is an effective and popular prior model in the field of regularization-based image processing. This paper focuses on TV for image restoration in the presence of impulse noise. This type of noise frequently arises in data acquisition and transmission due to many reasons, e.g. a faulty sensor or analog-to-digital converter errors. Removing this noise is an important task in i...

In this paper, we propose a variational segmentation model to deal with intensity inhomogeneity and Poisson noise. An energy functional is first proposed, which uses a data-fidelity term deduced from Poisson distribution instead of the usual L2 norm as a measure of fidelity. Due to the new data-fidelity measure, this energy functional can fit the image intensity more accurately while it can dim...

We present an adaptive regularization scheme for optimizing composite energy functionals arising in image analysis problems. The scheme automatically trades off data fidelity and regularization depending on the current data fit during the iterative optimization, so that regularization is strongest initially, and wanes as data fidelity improves, with the weight of the regularizer being minimized...

We report on a numerical evaluation of the statistical bootstrap as a technique for radio-interferometric imaging fidelity assessment. The development of a fidelity assessment technique is an important scientific prerequisite for automated pipeline reduction of data from modern radio interferometers. We evaluate the statistical performance of two bootstrap methods, the model-based bootstrap and...

We propose and state a novel scheme for image magnification. It is formulated as a minimization problem which incorporates a data fidelity and a regularization term. Data fidelity is modeled using a wavelet transformation operator while the Total Generalized Variation functional of second order is applied for regularization. Well-posedness is obtained in a function space setting and an efficien...

Traditional visual quality metrics measure fidelity instead of quality, even though fidelity, i.e. the accuracy of the reproduction of the original on the display, is just one of the many factors determining the overall perceived quality. In this paper, the addition of image appeal attributes is investigated in order to bridge this gap. Sharpness and colorfulness are identified among these attr...

Traditional visual quality metrics measure fidelity instead of quality, even though fidelity, i.e. the accuracy of the reproduction of the original on the display, is just one of the many factors determining the overall perceived quality. In this paper, the addition of image appeal attributes is investigated in order to bridge this gap. Sharpness and colorfulness are identified among these attr...

We present wave-optics calculations of the temporal and spatial evolution from random noise of a double phase-conjugate mirror in photorefractive media that show its image exchange and phase-reversal properties. The calculations show that for values of coupling coefficient times length greater than two the process exhibits excellent conjugation fidelity, behaves as an oscillator, and continues ...