Edge enhancement

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

Edge enhancement for thermal-visible combined images and cameras

Abstract: Systems and methods directed toward combining visible light and infrared images can include processing visible light image data to determine an edge factor value for a plurality of visible light pixels corresponding to the strength of an edge at that location The edge factor value can be determined using features from the visible light image data and an edge gain input, which may be adjustable by a user The edge factor values are combined with an edge midscale value to create a first set of modified visible light image data including pixels emphasized based on the strength of the edge in the visible light image The modified visible light image data is combined with infrared image data to create combined image data having contribution from the infrared image data and the edge factor values from the visible light image data

Edge enhancement by negative Poincare–Hopf index filters

Abstract: Phase and polarization are interrelated quantities, and hence polarization elements that perform like phase elements can be designed. In this Letter, we show that a polarizing element producing a negative Poincare–Hopf (PH) index beam can be used as a spatial filter to perform edge enhancement. Either isotropic or anisotropic edge enhancement can be achieved by polarization selection of the light that illuminates the sample. A conventional microscope imaging system is modified into a polarization-selective optical Fourier processor. Experimental results are presented to show that negative PH index filters, producing a set of orthogonal polarization distribution and their superpositions, can also be used for edge enhancement in optical signal processing.

An effecive night video enhancement algorithm

Abstract: Night video enhancement is important for video surveillance since many objects or activities of interest occur in a dark environment which cannot be seen easily without enhancement. In this paper, we discuss several problems of existing techniques for illumination-fusion based night video enhancement, which fuses video frames from day-time backgrounds and night-time video. We then present a simple enhancement algorithm without these problems. The algorithm uses an additive enhancement term with foreground object extraction and constrained low-passed object illumination to avoid light-inversion and sensitivity problems and to reduce ghost patterns. Experimental results show the effectiveness and robustness of the proposed algorithm.

Image enhancement using warping technique

Abstract: An image enhancement algorithm based on a warping technique is presented. The warping map is chosen in order to sharpen the edges of the image. In contrast to other algorithms, enhancement is performed without introducing overshoot in sharp edges and without amplifying the noise present in the original image.

Guided Image Filtering with Arbitrary Window Function

Abstract: In this paper, we propose an extension of guided image filtering to support arbitrary window functions. The guided image filtering is a fast edge-preserving filter based on a local linearity assumption. The filter supports not only image smoothing but also edge enhancement and image interpolation. The guided image filter assumes that an input image is a local linear transformation of a guidance image, and the assumption is supported in a local finite region. For realizing the supposition, the guided image filtering consists of a stack of box filtering. The limitation of the guided image filtering is flexibilities of kernel shape setting. Therefore, we generalize the formulation of the guide image filter by using the idea of window functions in image signal processing to represent arbitrary kernel shapes. Also, we reveal the relationship between the guided image filtering and the variants of this filter.