Name
points_harris_binomialT_points_harris_binomialPointsHarrisBinomialpoints_harris_binomialPointsHarrisBinomialPointsHarrisBinomial — Detect points of interest using the binomial approximation of the Harris
operator.
Herror points_harris_binomial(Hobject Image, const HTuple& MaskSizeGrad, const HTuple& MaskSizeSmooth, const HTuple& Alpha, const HTuple& Threshold, const HTuple& Subpix, HTuple* Row, HTuple* Column)
HTuple HImage::PointsHarrisBinomial(const HTuple& MaskSizeGrad, const HTuple& MaskSizeSmooth, const HTuple& Alpha, const HTuple& Threshold, const HTuple& Subpix, HTuple* Column) const
void PointsHarrisBinomial(const HObject& Image, const HTuple& MaskSizeGrad, const HTuple& MaskSizeSmooth, const HTuple& Alpha, const HTuple& Threshold, const HTuple& Subpix, HTuple* Row, HTuple* Column)
void HImage::PointsHarrisBinomial(Hlong MaskSizeGrad, Hlong MaskSizeSmooth, double Alpha, const HTuple& Threshold, const HString& Subpix, HTuple* Row, HTuple* Column) const
void HImage::PointsHarrisBinomial(Hlong MaskSizeGrad, Hlong MaskSizeSmooth, double Alpha, double Threshold, const HString& Subpix, HTuple* Row, HTuple* Column) const
void HImage::PointsHarrisBinomial(Hlong MaskSizeGrad, Hlong MaskSizeSmooth, double Alpha, double Threshold, const char* Subpix, HTuple* Row, HTuple* Column) const
void HOperatorSetX.PointsHarrisBinomial(
[in] IHUntypedObjectX* Image, [in] VARIANT MaskSizeGrad, [in] VARIANT MaskSizeSmooth, [in] VARIANT Alpha, [in] VARIANT Threshold, [in] VARIANT Subpix, [out] VARIANT* Row, [out] VARIANT* Column)
VARIANT HImageX.PointsHarrisBinomial(
[in] Hlong MaskSizeGrad, [in] Hlong MaskSizeSmooth, [in] double Alpha, [in] VARIANT Threshold, [in] BSTR Subpix, [out] VARIANT* Column)
static void HOperatorSet.PointsHarrisBinomial(HObject image, HTuple maskSizeGrad, HTuple maskSizeSmooth, HTuple alpha, HTuple threshold, HTuple subpix, out HTuple row, out HTuple column)
void HImage.PointsHarrisBinomial(int maskSizeGrad, int maskSizeSmooth, double alpha, HTuple threshold, string subpix, out HTuple row, out HTuple column)
void HImage.PointsHarrisBinomial(int maskSizeGrad, int maskSizeSmooth, double alpha, double threshold, string subpix, out HTuple row, out HTuple column)
points_harrispoints_harrisPointsHarrispoints_harrisPointsHarrisPointsHarris extracts points of interest from an image
ImageImageImageImageImageimage. The Harris operator is based upon the smoothed matrix
/ \
| 2 |
| Ix Ix Iy |
M = G * | |,
| 2 |
| Ix Iy Iy |
\ /
where G stands for a Binomial smoothing of size
MaskSizeSmoothMaskSizeSmoothMaskSizeSmoothMaskSizeSmoothMaskSizeSmoothmaskSizeSmooth and Ix and Iy are
the first derivatives of the image, computed with a Sobel
filter of size MaskSizeGradMaskSizeGradMaskSizeGradMaskSizeGradMaskSizeGradmaskSizeGrad. The resulting points are the
positive local extrema of
2
Det(M) - AlphaAlphaAlphaAlphaAlphaalpha*(Trace(M)) .
If necessary, they can be restricted to points with a minimum filter
response of ThresholdThresholdThresholdThresholdThresholdthreshold. By default the coordinates of the points
are calculated with subpixel accuracy. This can be turned off by setting
the parameter SubpixSubpixSubpixSubpixSubpixsubpix to 'off'.
- Multithreading type: reentrant (runs in parallel with non-exclusive operators).
- Multithreading scope: global (may be called from any thread).
- Automatically parallelized on internal data level.
Amount of binomial smoothing used for the calculation
of the gradient.
Default value: 5
Suggested values: 3, 5, 7, 9, 11, 15, 21, 31
Typical range of values: 3
≤
MaskSizeGrad
MaskSizeGrad
MaskSizeGrad
MaskSizeGrad
MaskSizeGrad
maskSizeGrad
≤
50
Recommended increment: 2
Restriction: MaskSizeGrad > 0
Amount of smoothing used for the integration of the
gradients.
Default value: 15
Suggested values: 3, 5, 7, 9, 11, 15, 21, 31
Typical range of values: 3
≤
MaskSizeSmooth
MaskSizeSmooth
MaskSizeSmooth
MaskSizeSmooth
MaskSizeSmooth
maskSizeSmooth
≤
50
Recommended increment: 2
Restriction: MaskSizeSmooth > 0
Weight of the squared trace of the squared gradient
matrix.
Default value: 0.08
Suggested values: 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08
Typical range of values: 0.001
≤
Alpha
Alpha
Alpha
Alpha
Alpha
alpha
≤
0.1
Minimum increment: 0.001
Recommended increment: 0.01
Restriction: Alpha > 0.0
Minimum filter response for the points.
Default value: 1000.0
Restriction: Threshold >= 0.0
Turn on or off subpixel refinement.
Default value:
'on'
"on"
"on"
"on"
"on"
"on"
List of values: 'off'"off""off""off""off""off", 'on'"on""on""on""on""on"
Row coordinates of the detected points.
Column coordinates of the detected points.
points_harrispoints_harrisPointsHarrispoints_harrisPointsHarrisPointsHarris returns 2 (H_MSG_TRUE) if all parameters are correct
and no error occurs during the execution. If the input is empty the
behavior can be set via
set_system('no_object_result',<Result>)set_system("no_object_result",<Result>)SetSystem("no_object_result",<Result>)set_system("no_object_result",<Result>)SetSystem("no_object_result",<Result>)SetSystem("no_object_result",<Result>). If
necessary, an exception is raised.
gen_cross_contour_xldgen_cross_contour_xldGenCrossContourXldgen_cross_contour_xldGenCrossContourXldGenCrossContourXld
points_foerstnerpoints_foerstnerPointsFoerstnerpoints_foerstnerPointsFoerstnerPointsFoerstner,
points_harrispoints_harrisPointsHarrispoints_harrisPointsHarrisPointsHarris,
points_lepetitpoints_lepetitPointsLepetitpoints_lepetitPointsLepetitPointsLepetit,
points_sojkapoints_sojkaPointsSojkapoints_sojkaPointsSojkaPointsSojka
C. Harris, M. Stephens: “A combined corner and edge
detector”. Proceedings of the 4th Alvey Vision Conference,
pp. 147-151, 1988.
V. Gouet, N.Boujemaa: “Object-based queries using color points of
interest”. IEEE Workshop on Content-Based Access of Image and Video
Libraries, CVPR/CBAIVL 2001, Hawaii, USA, 2001.
Foundation