Edge enhancement

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

Anisotropic edge enhancement with spiral zone plate under femtosecond laser illumination.

Abstract: Fractional and de-centered phase spiral zone plates (SZPs) are proposed for anisotropic edge enhancement using a femtosecond laser. The transmission functions of the two types of phase SZPs are deduced and the diffraction distributions are theoretically analyzed and simulated as well. By setting the fractional topological charge p and the orientation angle ϑ of a fractional SZP (FSZP), the intensity and the direction of the anisotropic edge enhancement can be controlled. A de-centered SZP (DSZP) can be obtained by shifting the coordinates of the traditional phase SZP while the topological charge equals to 1. The intensity and direction of the anisotropic edge enhancement can be controlled by setting the displacement distance r0 and the azimuthal angle φ0 of a DSZP. The anisotropic edge enhancement of the two phase SZPs was experimentally demonstrated with a phase pattern and living biological cells under femtosecond laser illumination.

Multichannel Object Detection for Detecting Suspected Trees With Pine Wilt Disease Using Multispectral Drone Imagery

Abstract: In this article, a multichannel convolutional neural network (CNN) based object detection was used to detect suspected trees of pine wilt disease after acquiring aerial photographs through a rotorcraft drone equipped with a multispectral camera. The acquired multispectral aerial photographs consist of RGB, green, red, NIR, and red edge spectral bands per shooting point. The aerial photographs for each band performed image calibration to correct radiation distortion, image alignment to correct the distance error of the lenses of a multispectral camera, and image enhancement to edge enhancement to highlight the features of objects in the image. After that, a large amount of data obtained through data augmentation were put into multichannel CNN-based object detection for training and test. As a result of verifying the detection performance of the trained model, excellent detection results were obtained with mAP 86.63% and average intersection over union 71.47%.

Stain detection and classification method and device for sensor of digital camera

Abstract: The invention discloses a stain detection method for a sensor of a digital camera, and a method and a device for classifying the sensor of the camera based on the detection method, wherein the method comprises the following steps: (1) inputting original image data and obtaining luminance component via interpolation, (2) low-pass filtering, (3) edge enhancement, (4) band-pass filtering, (5) image binaryzation operation and morphological dilation, (6) connectivity area abstraction, (7) marking stain in an original image, (8) classifying the sensor and outputting image level. The invention is divided as two function modules which are used for detecting the stain and classifying the sensor. A contiguous item of a classification decision function is from features such as quantity, area, and color depth of the stain detected in a shooting image. The method and the device of the invention is simple and efficient and can be used for fast detecting stain position on the sensor and carrying out accurate level evaluation to current sensor according to the feature of theses stains.

Fast image super-resolution using Connected Component enhancement

Abstract: The paper focuses on reconstructing the discontinuity between homogenous color regions in an interpolated image to improve its perceptual quality. A low-resolution input image is firstly interpolated and then decomposed into several patches. Each patch is then segmented into multiple homogenous regions using connected component analysis technique. Then a spatial-filter is applied to enhance the color/intensity transition between neighboring components. The designed spatial-filter combines the advantages of both bilateral-filtering and unsharp masking methods, with high computational efficiency. The proposed method can be used for image/video super-resolution applications. Experimental results are promising.

Picture enhancement in video and block-coded image sequences

Abstract: We propose a sharpness enhancement technique for video and decoded image sequences. Basically, the enhancement is accomplished by adding overshoot to luminance edges in an unsharp masking-like way. However, the optimal amount of overshoot added for a high image quality depends on the local image statistics. For this purpose, controls are introduced, to improve the performances and to adapt the operator to moving sequences with different characteristics. Both spatial and temporal information is used to enhance details, avoiding blocking artifacts and noise.