points_lepetitT_points_lepetitPointsLepetitPointsLepetitpoints_lepetit (算子名称)

名称

points_lepetitT_points_lepetitPointsLepetitPointsLepetitpoints_lepetit — Detect points of interest using the Lepetit operator.

参数签名

描述

points_lepetitpoints_lepetitPointsLepetitPointsLepetitPointsLepetitpoints_lepetit extracts points of interest like corners or blob-like structures from ImageImageImageImageimageimage. The ImageImageImageImageimageimage is first smoothed with a median of size 3x3. Then, all the gray values on a circle with radius RadiusRadiusRadiusRadiusradiusradius around an interest point candidate (m) are examined. The absolute differences of two diagonally opposed gray values (m1,m2) on the circle to the central pixel m is computed. At least one of these differences has to be larger than MinCheckNeighborDiffMinCheckNeighborDiffMinCheckNeighborDiffMinCheckNeighborDiffminCheckNeighborDiffmin_check_neighbor_diff. All diagonally opposed pixels on the circle must fulfill that condition. To suppress detection of points at edges that have a small curvature (aliasing), it is possible to compute CheckNeighborCheckNeighborCheckNeighborCheckNeighborcheckNeighborcheck_neighbor further differences of circle point neighbors of m1 and m2 to the center, that as well fulfill the above criteria. By computing all gray value differences of the circle points to the center, a mean gray value difference is determined. That value has to be larger than MinScoreMinScoreMinScoreMinScoreminScoremin_score and allows to restrict the results to points with high contrast. By computing the score of all eight neighbors of m, it is possible to fit a quadratic equation to that. The maxima of that equation determines a subpixel accurate interest point position. By setting the parameter SubpixSubpixSubpixSubpixsubpixsubpix to 'interpolation' (default) or 'none', it is possible to turn that refinement step on or off. The resulting points are returned in RowRowRowRowrowrow and ColumnColumnColumnColumncolumncolumn. 该算子 points_lepetitpoints_lepetitPointsLepetitPointsLepetitPointsLepetitpoints_lepetit can especially be used for very fast interest point extraction. The results are however less robust than points extracted by points_harrispoints_harrisPointsHarrisPointsHarrisPointsHarrispoints_harris for example.

注意

Note that filter operators may return unexpected results if an image with a reduced domain is used as input. Please refer to the chapter 过滤器.

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)。
• Automatically parallelized on domain level.

参数表

可能的前置算子

gauss_filtergauss_filterGaussFilterGaussFilterGaussFiltergauss_filter

可替代算子

points_foerstnerpoints_foerstnerPointsFoerstnerPointsFoerstnerPointsFoerstnerpoints_foerstner, points_harrispoints_harrisPointsHarrisPointsHarrisPointsHarrispoints_harris, points_harris_binomialpoints_harris_binomialPointsHarrisBinomialPointsHarrisBinomialPointsHarrisBinomialpoints_harris_binomial, points_sojkapoints_sojkaPointsSojkaPointsSojkaPointsSojkapoints_sojka

模块

Foundation

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