图像滤波

App

 图像区域分析器 Browse and filter connected components in an image

函数

 `fspecial` 创建预定义的二维滤波器 `fspecial3` Create predefined 3-D filter `convmtx2` 2-D convolution matrix
 `imfilter` 多维图像的 N 维滤波 `roifilt2` Filter region of interest (ROI) in image `nlfilter` General sliding-neighborhood operations `imgaussfilt` 图像的二维高斯滤波 `imgaussfilt3` 3-D Gaussian filtering of 3-D images `wiener2` 二维自适应去噪滤波 `medfilt2` 二维中位数滤波 `medfilt3` 3-D median filtering `modefilt` 2-D and 3-D mode filtering `ordfilt2` 2-D order-statistic filtering `stdfilt` Local standard deviation of image `rangefilt` Local range of image `entropyfilt` Local entropy of grayscale image `imboxfilt` 2-D box filtering of images `imboxfilt3` 3-D box filtering of 3-D images `fibermetric` Enhance elongated or tubular structures in image `maxhessiannorm` Maximum of Frobenius norm of Hessian of matrix `padarray` 填充数组
 `imbilatfilt` Bilateral filtering of images with Gaussian kernels `imdiffuseest` Estimate parameters for anisotropic diffusion filtering `imdiffusefilt` Anisotropic diffusion filtering of images `imguidedfilter` Guided filtering of images `imnlmfilt` Non-local means filtering of image `burstinterpolant` Create high-resolution image from set of low-resolution burst mode images
 `gabor` Create Gabor filter or Gabor filter bank `imgaborfilt` 将 Gabor 滤波器或滤波器组应用于二维图像
 `bwareafilt` 按大小从二值图像中提取对象 `bwpropfilt` Extract objects from binary image using properties
 `integralImage` Calculate 2-D integral image `integralImage3` Calculate 3-D integral image `integralBoxFilter` 2-D box filtering of integral images `integralBoxFilter3` 3-D box filtering of 3-D integral images
 `freqspace` 频率响应的频率间距 `freqz2` 2-D frequency response `fsamp2` 2-D FIR filter using frequency sampling `ftrans2` 2-D FIR filter using frequency transformation `fwind1` 2-D FIR filter using 1-D window method `fwind2` 2-D FIR filter using 2-D window method

主题

空间域中的图像滤波入门

Filter Grayscale and Truecolor (RGB) Images using imfilter Function

This example shows how to filter an image with a 5-by-5 averaging filter containing equal weights.

Filter Images Using Predefined Filter

This example shows how to create a type of special filter called an unsharp masking filter, which makes edges and detail in an image appear sharper.

imfilter 边界填充选项

去噪滤波

Reduce Noise in Image Gradients

This example shows how to reduce noise associated with computing image gradients.

边缘保持滤波

Perform Flash/No-flash Denoising with Guided Filter

This example shows how to reduce noise from an image while using a guidance image to preserve the sharpness of edges.

Segment Thermographic Image after Edge-Preserving Filtering

This example shows how to segment a hot object from the background in a thermographic image.

积分图像域滤波

Integral Image

Integral images are a quick way to represent images for filtering. In an integral image, the value of each pixel is the summation of the pixels above and to the left of it.

Apply Multiple Filters to Integral Image

This example shows how to smooth an image by different amounts by applying box filters of varying sizes to the integral image.

频域滤波

Design Linear Filters in the Frequency Domain

You can design filters that modify the frequency content of images. Filtering in the frequency domain is often faster than filtering in the spatial domain.