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)
This paper presents a new method for unsharp masking for contrast enhancement of images. The approach employs an adaptive filter that controls the contribution of the sharpening path in such a way that contrast enhancement occurs in high detail areas and little or no image sharpening occurs in smooth areas.
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)
Rule-based fuzzy operators are a novel class of operators specifically designed in order to apply the principles of approximate reasoning to digital image processing. This paper shows how a fuzzy operator that is able to perform detail sharpening but is insensitive to noise can be designed. The results obtainable by the proposed technique in the enhancement… (More)
New electronic imaging devices and products, such as cameras or image retouch software, demand new solutions for image correction and enhancement. In this paper we describe significant modifications to the Retinex approach, a human vision based model proposed by Land, introducing nonlinear filtering and functions to obtain improvements in both local and… (More)
We propose a new algorithm to digitally restore vintage photographic prints affected by foxing and water blotches. It semi-automatically recovers the defects utilizing the features of the stains. The restoration process enhances the residual image information still present in the area. It is composed of three different steps: in-painting,… (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)
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)
A novel scheme for edge-preserving image interpolation is introduced, which is based on the use of a simple non-linear fillter which accurately reconstructs sharp edges. Simulation results show the superior performances of the proposed approach with respect to other interpolation techniques.