Edge enhancement

About: Edge enhancement is a research topic. Over the lifetime, 2324 publications have been published within this topic receiving 30962 citations.

Image subtraction using fixed holograms in photorefractive Bi 12 TiO 20 crystals

Abstract: A simple method for image subtraction by two-wave mixing in photorefractive cubic Bi12 TiO20 crystals is proposed and demonstrated. Intensity inversion and edge enhancement are also achieved.

Non-local edge enhanced imaging with incoherent thermal light

Abstract: Spiral phase contrast imaging is an effective technique for the edge enhancement of a phase object. The spiral phase filter is the core component of the system and it provides sensitivity to the phase and amplitude gradients of the object. General spiral phase contrast imaging depends on the 4f imaging system in a single light beam with the coherent light source of visible or infrared wavelengths. Here, we constructed a non-local edge enhanced imaging system using an incoherent thermal light source. The detected object and the adopted spiral phase filter were non-locally placed in two separated light beams. The edge enhanced ghost image of the phase object can then be achieved through second-order intensity correlation measurements. The classical nature of the spatial degree of freedom of our proposed edge enhanced ghost imaging system was also demonstrated through the measurement of Bell-type inequality.

Directional Unsharp Masking-Based Approach for Color Image Enhancement

Abstract: In this paper, we present an unsharp masking-based approach for noise smoothing and edge enhancing in multichannel images. The proposed structure is similar to the conventional unsharp masking structure, however, the enhancement is allowed only in the direction of maximal change and the enhancement parameter is computed as a nonlinear function of the rate of change. The proposed scheme enhances the true details, limits the overshoot near sharp edges and attenuates noise in flat areas. Moreover the use of the control function eliminates the need for the subjective coefficient λ used in the conventional unsharp masking technique.

Pattern recognition using incoherent OTF synthesis and edge enhancement.

Abstract: This paper describes a system for pattern recognition using an incoherent-optical correlator. The system uses optical transfer function synthesis to perform correlations with an edge-enhanced image of the object or pattern being sought. The resulting correlations are free of bias and show good discrimination between objects. In addition, the difficult or time-consuming computations are performed before the operation of the system; this reduces the amount of postprocessing by computer and should allow real-time operation at video rates.