nonmax_suppression_dirnonmax_suppression_dirNonmaxSuppressionDirNonmaxSuppressionDirnonmax_suppression_dir (算子名称)

名称

nonmax_suppression_dirnonmax_suppression_dirNonmaxSuppressionDirNonmaxSuppressionDirnonmax_suppression_dir — Suppress non-maximum points on an edge using a direction image.

参数签名

nonmax_suppression_dir(ImgAmp, ImgDir : ImageResult : Mode : )

描述

nonmax_suppression_dirnonmax_suppression_dirNonmaxSuppressionDirNonmaxSuppressionDirNonmaxSuppressionDirnonmax_suppression_dir suppresses all points in the regions of the image ImgAmpImgAmpImgAmpImgAmpimgAmpimg_amp whose gray values are not local (directed) maxima. ImgDirImgDirImgDirImgDirimgDirimg_dir is a direction image giving the direction perpendicular to the local maximum (Unit: 2 degrees, i.e., 50 degrees are coded as 25 in the image). Such images are returned, for example, by edges_imageedges_imageEdgesImageEdgesImageEdgesImageedges_image. Two modes of operation can be selected:

'nms': Each point in the image is tested whether its gray value is a local maximum perpendicular to its direction. In this mode only the two neighbors closest to the given direction are examined. If one of the two gray values is greater than the gray value of the point to be tested, it is suppressed (i.e., removed from the input region. The corresponding gray value remains unchanged).
'inms': Like 'nms'"nms""nms""nms""nms""nms". However, the two gray values for the test are obtained by interpolation from four adjacent points.

运行信息

多线程类型:可重入(与非独占操作符并行运行)。
多线程作用域:全局(可以从任何线程调用)。
在元组级别自动并行化。

参数表

ImgAmpImgAmpImgAmpImgAmpimgAmpimg_amp (input_object) singlechannelimage(-array) → object (byte / uint2 / real)

Amplitude (gradient magnitude) image.

ImgDirImgDirImgDirImgDirimgDirimg_dir (input_object) singlechannelimage(-array) → object (direction)

Direction image.

ImageResultImageResultImageResultImageResultimageResultimage_result (output_object) image(-array) → object (byte / uint2 / real)

Image with thinned edge regions.

ModeModeModeModemodemode (input_control) string → (string)

Select non-maximum-suppression or interpolating NMS.

Default: 'nms' "nms" "nms" "nms" "nms" "nms"

List of values: 'inms'"inms""inms""inms""inms""inms", 'nms'"nms""nms""nms""nms""nms"

结果

nonmax_suppression_dirnonmax_suppression_dirNonmaxSuppressionDirNonmaxSuppressionDirNonmaxSuppressionDirnonmax_suppression_dir returns 2 ( H_MSG_TRUE) if all parameters are correct. The behavior with respect to the input images and output regions can be determined by setting the values of the flags 'no_object_result'"no_object_result""no_object_result""no_object_result""no_object_result""no_object_result", 'empty_region_result'"empty_region_result""empty_region_result""empty_region_result""empty_region_result""empty_region_result", and 'store_empty_region'"store_empty_region""store_empty_region""store_empty_region""store_empty_region""store_empty_region" with set_systemset_systemSetSystemSetSystemSetSystemset_system. 如有必要，将引发异常。

可能的前置算子

edges_imageedges_imageEdgesImageEdgesImageEdgesImageedges_image, sobel_dirsobel_dirSobelDirSobelDirSobelDirsobel_dir, frei_dirfrei_dirFreiDirFreiDirFreiDirfrei_dir

可能的后置算子

thresholdthresholdThresholdThresholdThresholdthreshold, hysteresis_thresholdhysteresis_thresholdHysteresisThresholdHysteresisThresholdHysteresisThresholdhysteresis_threshold

可替代算子

nonmax_suppression_ampnonmax_suppression_ampNonmaxSuppressionAmpNonmaxSuppressionAmpNonmaxSuppressionAmpnonmax_suppression_amp

参考其它

skeletonskeletonSkeletonSkeletonSkeletonskeleton

References

S.Lanser: “Detektion von Stufenkanten mittels rekursiver Filter nach Deriche”; Diplomarbeit; Technische Universität München, Institut für Informatik, Lehrstuhl Prof. Radig; 1991.
J.Canny: “Finding Edges and Lines in Images”; Report, AI-TR-720; M.I.T. Artificial Intelligence Lab., Cambridge; 1983.

模块

Foundation

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