local_max_sub_pixT_local_max_sub_pixLocalMaxSubPixLocalMaxSubPixlocal_max_sub_pix (算子)
名称
local_max_sub_pixT_local_max_sub_pixLocalMaxSubPixLocalMaxSubPixlocal_max_sub_pix — 图像中局部最大值的亚像素精度检测。
签名
void LocalMaxSubPix(const HObject& Image, const HTuple& Filter, const HTuple& Sigma, const HTuple& Threshold, HTuple* Row, HTuple* Column)
void HImage::LocalMaxSubPix(const HString& Filter, double Sigma, double Threshold, HTuple* Row, HTuple* Column) const
void HImage::LocalMaxSubPix(const char* Filter, double Sigma, double Threshold, HTuple* Row, HTuple* Column) const
void HImage::LocalMaxSubPix(const wchar_t* Filter, double Sigma, double Threshold, HTuple* Row, HTuple* Column) const
(
Windows only)
def local_max_sub_pix(image: HObject, filter: str, sigma: float, threshold: float) -> Tuple[Sequence[float], Sequence[float]]
描述
local_max_sub_pixlocal_max_sub_pixLocalMaxSubPixLocalMaxSubPixLocalMaxSubPixlocal_max_sub_pix extracts local maxima from the image
ImageImageImageImageimageimage with subpixel precision.
To do so, in each point the input image is approximated by a quadratic
polynomial in x and y and subsequently the polynomial is examined for
local maxima. The partial derivatives, which are
necessary for setting up the polynomial, are calculated either with various
Gaussian derivatives or using the facet model, depending on FilterFilterFilterFilterfilterfilter.
In the first case, SigmaSigmaSigmaSigmasigmasigma determines the size of the Gaussian
kernels, while in the second case, before being processed the input image is
smoothed by a Gaussian whose size is determined by SigmaSigmaSigmaSigmasigmasigma.
Therefore, 'facet'"facet""facet""facet""facet""facet" results in a faster extraction at the expense
of slightly less accurate results. A point is accepted to be a local maximum
if both eigenvalues of the Hessian matrix are smaller than
-ThresholdThresholdThresholdThresholdthresholdthreshold. The eigenvalues correspond to the curvature of the gray
value surface.
注意
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)。
- 在内部数据级别上自动并行化。
参数
ImageImageImageImageimageimage (输入对象) singlechannelimage → objectHImageHObjectHImageHobject (byte / int1 / int2 / uint2 / int4 / real)
输入图像。
FilterFilterFilterFilterfilterfilter (输入控制) string → HTuplestrHTupleHtuple (string) (string) (HString) (char*)
Method for the calculation of the partial derivatives.
默认值:
'facet'
"facet"
"facet"
"facet"
"facet"
"facet"
值列表:
'facet'"facet""facet""facet""facet""facet", 'gauss'"gauss""gauss""gauss""gauss""gauss"
ThresholdThresholdThresholdThresholdthresholdthreshold (输入控制) real → HTuplefloatHTupleHtuple (real) (double) (double) (double)
Minimum absolute value of the eigenvalues of the
Hessian matrix.
默认值:
5.0
建议值:
2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0
限制:
Threshold >= 0.0
RowRowRowRowrowrow (输出控制) point.y-array → HTupleSequence[float]HTupleHtuple (real) (double) (double) (double)
Row coordinates of the detected maxima.
ColumnColumnColumnColumncolumncolumn (输出控制) point.x-array → HTupleSequence[float]HTupleHtuple (real) (double) (double) (double)
Column coordinates of the detected maxima.
结果
local_max_sub_pixlocal_max_sub_pixLocalMaxSubPixLocalMaxSubPixLocalMaxSubPixlocal_max_sub_pix returns 2 (
H_MSG_TRUE)
if all parameters are correct
and no error occurs during the execution. 如果输入为空则可设置行为通过 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。
可能的后继
gen_cross_contour_xldgen_cross_contour_xldGenCrossContourXldGenCrossContourXldGenCrossContourXldgen_cross_contour_xld,
disp_crossdisp_crossDispCrossDispCrossDispCrossdisp_cross
替代
critical_points_sub_pixcritical_points_sub_pixCriticalPointsSubPixCriticalPointsSubPixCriticalPointsSubPixcritical_points_sub_pix,
local_min_sub_pixlocal_min_sub_pixLocalMinSubPixLocalMinSubPixLocalMinSubPixlocal_min_sub_pix,
saddle_points_sub_pixsaddle_points_sub_pixSaddlePointsSubPixSaddlePointsSubPixSaddlePointsSubPixsaddle_points_sub_pix
另见
local_maxlocal_maxLocalMaxLocalMaxLocalMaxlocal_max,
plateausplateausPlateausPlateausPlateausplateaus,
plateaus_centerplateaus_centerPlateausCenterPlateausCenterPlateausCenterplateaus_center
模块
基础