Chair: Aggelos K. Katsaggelos, Northwestern University, USA
Min-Cheol Hong, Northwestern University (U.S.A.)
Tania Stathaki, Imperial College (U.K.)
Aggelos K. Katsaggelos, Northwestern University (U.S.A.)
In this paper, we propose a spatially adaptive image restoration algorithm, using local statistics. The local variance, mean and maximum value are utilized to constraint the solution space. These parameters axe computed at each iteration step using partially restored image. A parameter defined by the user determines the degree of local smoothness imposed on the solution. The resulting iterative algorithm exhibits increased convergence speed when compared with the nonadaptive algorithm. In addition, a smooth solution with a controlled degree of smoothness is obtained. Experimental results demonstrate the capability of the proposed algorithm.
Michalis Pappas, Aristotle University of Thessaloniki (Greece)
Ioannis Pitas, Aristotle University of Thessaloniki (Greece)
Many old paintings suffer from the effects of certain physicochemical phenomena, that can seriously degrade their overall visual appearance. Cleaning methods, that utilize chemical treatment substances, can not always be used, due to possible deterioration of the painting surface or reduction of the painting artistic value. Digital image processing techniques can be utilized for the purpose of restoring the original appearance of a painting, with minimal physical interaction with the painting surface. In this paper, a number of methods are presented which can yield satisfactory results. Indeed, simulation results indicate that acceptable restoration performance may be attained, despite the small size of painting surface data utilized
Pauli Kuosmanen, Tampere University of Technology (Finland)
Jaakko T. Astola, Tampere University of Technology (Finland)
Kari Daviosson, Tampere University of Technology (Finland)
Katriina Halonen, Tampere University of Technology (Finland)
A new method for signature embedding and detection for digital signals is introduced. The method uses local characteristics in the signal to conceal the signature, also called the watermark in the signal. The watermark follows therefore closely the signal characteristics and is difficult to detect without knowing the right parameters of the embedding procedure.
Joseph Y. Pai, University of Minnesota (U.S.A.)
Lori Lucke, University of Minnesota (U.S.A.)
Color image expansion is necessary for printing images on large format printers. A new Viewing Effect Algorithm is introduced for image expansion in this paper. The algorithm is developed to measure the viewing quality of the expansion results from various image expansion techniques. The principle behind the algorithm is based on viewing angle and distance to the image to calculate a viewing effect number. The viewing effect number is used to compare the expansion quality among various popular expansion techniques. Simulation results show this algorithm can provide qualitative comparisons for the various expansion techniques.
Jennifer Guani Dy, Purdue University (U.S.A.)
Jan P. Allebach, Purdue University (U.S.A.)
This paper presents an algorithm for interpolating binary images. More specifically it deals with a factor of two interpolation in the horizontal and vertical direction. The algorithm uses a look-up table built on a training set of high and low resolution images. The conditional probabilities of the high resolution pixels based on a corresponding neighborhood of low resolution pixels axe used to predict the interpolated image. Then a nonlinear smoothing filter is applied to enhance the resulting image. Since the algorithm is look-up table based, it facilitates simple implementation suitable for printers.
Daisuke Sekiwa, Musashi Institute of Technology (Japan)
Akira Taguchi, Musashi Institute of Technology (Japan)
A neural network for edge-preserving image interpolation is introduced, which is based on the non-linear procedure which is presented by Greenspan [21. Simulation results show the superior performances of the proposed approach with respect to other interpolation techniques.