Sir, I read with interest the article ‘Enhancing digital images using unsharp-mask’ by Taneja.[1] The author has discussed a really interesting aspect of dermatological photography. The use of a sharpening tool is definitely helpful in enhancing communication via images, especially in the context of seeing images on the monitor screens, like in teledermatology, but whether and to what extent th...

Blurred edges appear sharper in motion than when they are stationary. We (Vision Research 38 (1998) 2108) have previously shown how such distortions in perceived edge blur may be accounted for by a model which assumes that luminance contrast is encoded by a local contrast transducer whose response becomes progressively more compressive as speed increases. If the form of the transducer is fixed ...

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.

Pan-sharpening aims to sharpen a low spatial resolution multispectral (MS) image by combining the spatial detail information extracted from a panchromatic (PAN) image. An effective pan-sharpening method should produce a high spatial resolution MS image while preserving more spectral information. Unlike traditional intensity-hue-saturation (IHS)and principal component analysis (PCA)-based multis...

Image data sharpening is a challenging field of remote sensing science, which has become more relevant as high spatial-resolution satellites and superspectral sensors have emerged. Although the spectral property is crucial for mineral mapping, spatial resolution is also important as it allows targeted minerals/rocks to be identified/interpreted in a spatial context. Therefore, improving the spa...

This paper presents the Adaptive Sharpening with Overshoot Control (ASOC), an algorithm for digital image contrast enhancement. The ASOC exploits a properly defined band-pass filter in order to better discriminate the "uniform/not uniform" zones of the input (blurred) image. A more aggressive sharpening is then performed on the textured zones, whilst the homogeneous regions are preserved.