sigma_imagesigma_imageSigmaImageSigmaImagesigma_image（算子）

名称

sigma_imagesigma_imageSigmaImageSigmaImagesigma_image — 使用西格玛滤波器进行非线性平滑。

签名

描述

算子 sigma_imagesigma_imageSigmaImageSigmaImageSigmaImagesigma_image carries out a non-linear smoothing of the gray values of all input images (ImageImageImageImageimageimage). All pixels in a rectangular window (MaskHeight x MaskWidth) are used to determine the new gray value of the central pixel of this window. First, the gray value standard deviation of all pixels in the window is calculated. Then, all pixels of the window with a gray value that differs from the gray value of the central pixel by less than SigmaSigmaSigmaSigmasigmasigma times this standard deviation are used to calculate the new gray value of the central pixel. The gray value of the central pixel is the average of the gray values of the selected pixels. If no pixel could be selected for the averaging of the gray values, the gray value of the central pixel remains unchanged.

有关平滑滤波器概念的说明，请参阅 滤波器 / 平滑 一章的引言。

注意

If even values instead of odd values are given for MaskHeightMaskHeightMaskHeightMaskHeightmaskHeightmask_height or MaskWidthMaskWidthMaskWidthMaskWidthmaskWidthmask_width, the routine uses the next larger odd values instead (this way the center of the filter mask is always explicitly determined).

请注意，若使用域缩减后的图像作为输入，滤波器算子可能会返回意外结果。请参阅 滤波器 一章

执行信息

• 多线程类型：可重入（与非独占算子并行运行）。
• 多线程作用域：全局（可从任何线程调用）。
• 在元组级别上自动并行化。
• 在通道级别上自动并行化。
• 在域级别上自动并行化。

参数

read_image(Image,'fabrik')
sigma_image(Image,ImageSigma,5,5,3)
dev_display(ImageSigma)

read_image(&Image,"fabrik");
sigma_image(Image,&ImageSigma,5,5,3);
disp_image(ImageSigma,WindowHandle);

read_image(Image,'fabrik')
sigma_image(Image,ImageSigma,5,5,3)
dev_display(ImageSigma)

read_image(Image,'fabrik')
sigma_image(Image,ImageSigma,5,5,3)
dev_display(ImageSigma)

read_image(Image,'fabrik')
sigma_image(Image,ImageSigma,5,5,3)
dev_display(ImageSigma)

复杂度

For each pixel: O(MaskHeight*MaskWidth).

结果

如果参数值正确，算子 sigma_imagesigma_imageSigmaImageSigmaImageSigmaImagesigma_image 返回值 2 (H_MSG_TRUE)。当输入为空（无可用输入图像）时，可设置行为通过算子 set_system('no_object_result',<Result>)set_system("no_object_result",<Result>)SetSystem("no_object_result",<Result>)SetSystem("no_object_result",<Result>)SetSystem("no_object_result",<Result>)set_system("no_object_result",<Result>)。如有必要，则抛出异常。

可能的前趋

read_imageread_imageReadImageReadImageReadImageread_image

可能的后继

thresholdthresholdThresholdThresholdThresholdthreshold, dyn_thresholddyn_thresholdDynThresholdDynThresholdDynThresholddyn_threshold, regiongrowingregiongrowingRegiongrowingRegiongrowingRegiongrowingregiongrowing

替代

anisotropic_diffusionanisotropic_diffusionAnisotropicDiffusionAnisotropicDiffusionAnisotropicDiffusionanisotropic_diffusion, rank_imagerank_imageRankImageRankImageRankImagerank_image

另见

smooth_imagesmooth_imageSmoothImageSmoothImageSmoothImagesmooth_image, binomial_filterbinomial_filterBinomialFilterBinomialFilterBinomialFilterbinomial_filter, gauss_filtergauss_filterGaussFilterGaussFilterGaussFiltergauss_filter, mean_imagemean_imageMeanImageMeanImageMeanImagemean_image

参考文献

R. Haralick, L. Shapiro; “Computer and Robot Vision”; Addison-Wesley, 1992, Seite 325

模块

基础