Bilateral filter

About: Bilateral filter is a research topic. Over the lifetime, 3500 publications have been published within this topic receiving 75582 citations.

A method and a system for processing images

Abstract: The present invention relates to a method and a system for processing images. The invention relates in particular to a method and a system for processing an image using interpolating. The method determines a variation value for different sets of pixels in a CCD, and the set of pixels with the highest correlation (lowest numeric value) is selected. A missing colour at a given pixel is expressed in terms of the information contained in the selected set of pixels. If the variation value is below a certain threshold, due to noise or other factors, an alternative set of pixels using a different variation method may be selected. The missing colour is estimated as a weighted sum of e.g. the green samples divided by the weighted sum of e.g. the red samples multiplied by the sampled value from the pixel to be estimated.

Digital image forming apparatus using subdivided pixels

Abstract: In a method of forming an image in a form of pixels, the density distribution around a target pixel is obtained by processing image signals of pixels neighboring the target pixel. The target pixel is sub-divided into a plurality of sub-pixels which form of matrix of n rows×m columns. The sub density distribution of the sub-pixels in the target pixel is assumed from the density distribution of the neighboring pixels. The density of each of sub-pixels is determined by multiplying the density of the target pixel, by a constant P and a density ratio of the corresponding sub-pixels in the sub density distribution.

Depth map enhancement method based on joint bilateral filter

Abstract: Considering the emergence of Microsoft Kinect has attracted attention not only from customers but also from researchers in the field of computer vision. Nonetheless, Kinect-generated depth maps usually contain various holes, especially at the edges of the front ground. In order to fill in the holes existing in the depth map, some methods that adopted color map guided in-painting or joint bilateral filter have been proposed to obtain missing depth pixels. However, these methods often caused edge blur. In this paper, the method is proposed that the holes and noises of the depth map are filled by the weighted joint bilateral filter and the fast marching algorithm based on the edge priority is further used to keep the edges smooth. To efficiently validate our method, we perform experiments on both the Kinect data and the Middlebury dataset, which provide qualitative and quantitative results. Experimental results show that our method has obtained the best performance of improvement of depth map for the smooth and edge regions and can perform real-time processing.

Content adaptive bilateral filtering

Abstract: Bilateral filter is perhaps the most popular and simplest edge-preserving local filter. However, it may produce halos near some edges due to unwanted smoothing of the edges. In this paper, a content adaptive bilateral filter is proposed to overcome this problem. Both spatial similarity and range similarity parameters of the proposed bilateral filter are adaptive to the content of an image to be filtered rather than being fixed as in the existing bilateral filter. The proposed filter preserves edges and smoothes flat areas better than the existing bilateral filter. It is applied to design a local tone mapping algorithm for high dynamic range images as well as a noise reduction algorithm for low dynamic range color images. Experimental results show that the resultant tone mapping algorithm produces images with better visual quality and at the same time halo artifacts are avoided from appearing in the tone mapped image. The resultant noise reduction algorithm can also produce images with higher structural similarity index values and better visual quality. Noise in smooth regions are more reduced and edges are preserved better in the de-noised image.