dots_imagedots_imageDotsImageDotsImage (Operator)


dots_imagedots_imageDotsImageDotsImage — Enhance circular dots in an image.


dots_image(Image : DotImage : Diameter, FilterType, PixelShift : )

Herror dots_image(const Hobject Image, Hobject* DotImage, const Hlong Diameter, const char* FilterType, const Hlong PixelShift)

Herror T_dots_image(const Hobject Image, Hobject* DotImage, const Htuple Diameter, const Htuple FilterType, const Htuple PixelShift)

void DotsImage(const HObject& Image, HObject* DotImage, const HTuple& Diameter, const HTuple& FilterType, const HTuple& PixelShift)

HImage HImage::DotsImage(Hlong Diameter, const HString& FilterType, Hlong PixelShift) const

HImage HImage::DotsImage(Hlong Diameter, const char* FilterType, Hlong PixelShift) const

HImage HImage::DotsImage(Hlong Diameter, const wchar_t* FilterType, Hlong PixelShift) const   (Windows only)

static void HOperatorSet.DotsImage(HObject image, out HObject dotImage, HTuple diameter, HTuple filterType, HTuple pixelShift)

HImage HImage.DotsImage(int diameter, string filterType, int pixelShift)


dots_imagedots_imageDotsImageDotsImageDotsImage enhances circular dots of diameter DiameterDiameterDiameterDiameterdiameter in the input image ImageImageImageImageimage. Hence, dots_imagedots_imageDotsImageDotsImageDotsImage is especially suited for the segmentation of dot prints, e.g., in OCR applications. The enhancement is performed by using matched filters with filter masks that are tuned for a particular dot size. For example, for DiameterDiameterDiameterDiameterdiameter = 5 the filter mask is given by: The parameter FilterTypeFilterTypeFilterTypeFilterTypefilterType selects whether 'dark'"dark""dark""dark""dark", 'light'"light""light""light""light", or 'all'"all""all""all""all" dots in the image should be enhanced. The PixelShiftPixelShiftPixelShiftPixelShiftpixelShift can be used either to increase the contrast of the output image (PixelShiftPixelShiftPixelShiftPixelShiftpixelShift > 0) or to dampen the values in extremely bright areas that would be cut off otherwise (PixelShiftPixelShiftPixelShiftPixelShiftpixelShift = -1).


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

Execution Information


ImageImageImageImageimage (input_object)  (multichannel-)image(-array) objectHImageHImageHobject (byte / uint2)

Input image.

DotImageDotImageDotImageDotImagedotImage (output_object)  (multichannel-)image(-array) objectHImageHImageHobject * (byte / uint2)

Output image.

DiameterDiameterDiameterDiameterdiameter (input_control)  integer HTupleHTupleHtuple (integer) (int / long) (Hlong) (Hlong)

Diameter of the dots to be enhanced.

Default value: 5

List of values: 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23

FilterTypeFilterTypeFilterTypeFilterTypefilterType (input_control)  string HTupleHTupleHtuple (string) (string) (HString) (char*)

Enhance dark, light, or all dots.

Default value: 'light' "light" "light" "light" "light"

List of values: 'all'"all""all""all""all", 'dark'"dark""dark""dark""dark", 'light'"light""light""light""light"

PixelShiftPixelShiftPixelShiftPixelShiftpixelShift (input_control)  integer HTupleHTupleHtuple (integer) (int / long) (Hlong) (Hlong)

Shift of the filter response.

Default value: 0

List of values: -1, 0, 1, 2

Possible Successors



laplacelaplaceLaplaceLaplaceLaplace, laplace_of_gausslaplace_of_gaussLaplaceOfGaussLaplaceOfGaussLaplaceOfGauss, diff_of_gaussdiff_of_gaussDiffOfGaussDiffOfGaussDiffOfGauss, derivate_gaussderivate_gaussDerivateGaussDerivateGaussDerivateGauss, convol_imageconvol_imageConvolImageConvolImageConvolImage