In image processing, Guided Image Filter is a non-linear filter that can smooth the image.
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In order to achieve the effect of smoothing the image, that is, removing noise, first define the output result image as the result of subtracting noise from the input image; at the same time, in order to make the output image meet the image boundary of the guide image, the output image is determined as Guide the linear combination of pictures.
The following is the basic model of the guided image filter
Guide picture
By the characteristics of the guide picture filter, several functions can be extended in addition to the original smoothing.
Guide image filtering detail enhancement
When an image image is both an output image and a guide image, it can be known that the base layer and the detail layer based on the boundary of the image will be obtained; therefore, to enhance the details according to the image, the energy of the detail layer can be enlarged After n times, it is superimposed back to the base layer to achieve the effect of enhancing details.
Guide image filtering depth map trimming
Regardless of the depth map produced by using light field technology or focal-stack, there will often be some holoes when the production is completed; and if guidance is used then An image filter, taking the original image as the guide image and the depth image as the input image, can obtain a complete , pit-free depth image.