Giovanni Ramponi

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The problem of image interpolation using linear techniques is dealt with in this paper. Conventional space-invariant methods are revisited and changed into space-variant ones, by introducing the concept of the warped distance among the pixels of an image. A better perceptual rendition of the image details is obtained in this way; this effect is proved both(More)
3-D RATIONAL FILTER FOR EDGE PRESERVING SMOOTHING Francesco Cocchia, Sergio Carrato, and Giovanni Ramponi D.E.E.I., University of Trieste, via Valerio, 10, 34100 Trieste, Italy tel.: +39.40.6767147; fax: +39.40.6763460 ABSTRACT | A nonlinear spatio-temporal lter capable of signi cantly attenuating noise in image sequences without corrupting image details is(More)
In the unsharp masking approach for image enhancement, a fraction of the highpass filtered version of the image is added to the original image to form the enhanced version. The method is simple, but it suffers from two serious drawbacks. First, it enhances the contrast in the darker areas perceptually much more strongly than that in the lighter areas.(More)
A frame interpolation algorithm for frame rate up-conversion of progressive image sequences is proposed. The algorithm is based on simple motion compensation and linear interpolation. A motion vector is searched for each pixel in the interpolated image and the resulting motion eld is median ltered to remove inconsistent vectors. Averaging along the motion(More)
The Cubic Unsharp Masking method is introduced in this paper. It is demonstrated, through both a statistical study and some computer simulations, that the proposed method has a much reduced noise sensitivity with respect to the linear unsharp masking technique and it permits to obtain perceptually pleasant results. The proposed operator also compares(More)