ClassesClassesClassesClasses | | | | Operators

get_grayvalget_grayvalGetGrayvalget_grayvalGetGrayvalGetGrayval (Operator)


get_grayvalget_grayvalGetGrayvalget_grayvalGetGrayvalGetGrayval — Access the gray values of an image object.


get_grayval(Image : : Row, Column : Grayval)

Herror get_grayval(const Hobject Image, const Hlong Row, const Hlong Column, double* Grayval)

Herror T_get_grayval(const Hobject Image, const Htuple Row, const Htuple Column, Htuple* Grayval)

Herror get_grayval(Hobject Image, const HTuple& Row, const HTuple& Column, double* Grayval)

Herror get_grayval(Hobject Image, const HTuple& Row, const HTuple& Column, HTuple* Grayval)

HTuple HImage::GetGrayval(const HTuple& Row, const HTuple& Column) const

void GetGrayval(const HObject& Image, const HTuple& Row, const HTuple& Column, HTuple* Grayval)

HTuple HImage::GetGrayval(const HTuple& Row, const HTuple& Column) const

double HImage::GetGrayval(Hlong Row, Hlong Column) const

void HOperatorSetX.GetGrayval(
[in] IHUntypedObjectX* Image, [in] VARIANT Row, [in] VARIANT Column, [out] VARIANT* Grayval)

VARIANT HImageX.GetGrayval(
[in] VARIANT Row, [in] VARIANT Column)

static void HOperatorSet.GetGrayval(HObject image, HTuple row, HTuple column, out HTuple grayval)

HTuple HImage.GetGrayval(HTuple row, HTuple column)

double HImage.GetGrayval(int row, int column)


The parameter GrayvalGrayvalGrayvalGrayvalGrayvalgrayval is a tuple of floating point numbers or integer numbers which returns the gray values of several pixels of ImageImageImageImageImageimage. For a multi-channel image, a group of elements, in particular one value for each channel (or two values for each channel for complex or vector field images), is returned for each pixel. The row coordinates of the pixels are specified in the tuple RowRowRowRowRowrow, the column coordinates are specified in the tuple ColumnColumnColumnColumnColumncolumn.

Note that get_grayvalget_grayvalGetGrayvalget_grayvalGetGrayvalGetGrayval does not take the domain of the image into account, i.e., if the domain has been reduced, e.g., with reduce_domainreduce_domainReduceDomainreduce_domainReduceDomainReduceDomain, gray values are returned even for points that lie outside the domain.


The type of the values of GrayvalGrayvalGrayvalGrayvalGrayvalgrayval depends on the type of the gray values of the channels of the image ImageImageImageImageImageimage. The operator get_grayvalget_grayvalGetGrayvalget_grayvalGetGrayvalGetGrayval produces quite some overhead. Typically, it is used to get single gray values of an image (e.g., get_mpositionget_mpositionGetMpositionget_mpositionGetMpositionGetMposition followed by get_grayvalget_grayvalGetGrayvalget_grayvalGetGrayvalGetGrayval). It is not suitable for programming image processing operations such as filters. In this case it is more useful to use the operator get_image_pointer1get_image_pointer1GetImagePointer1get_image_pointer1GetImagePointer1GetImagePointer1 and to directly use the C or C++ interface for integrating own procedures.



ImageImageImageImageImageimage (input_object)  (multichannel-)image objectHImageHImageHImageHImageXHobject (byte / direction / cyclic / int1 / int2 / uint2 / int4 / int8 / real / complex / vector_field)

Image whose gray value is to be accessed.

RowRowRowRowRowrow (input_control)  point.y(-array) HTupleHTupleHTupleVARIANTHtuple (integer) (int / long) (Hlong) (Hlong) (Hlong) (Hlong)

Row coordinates of pixels to be viewed.

Default value: 0

Suggested values: 0, 64, 128, 256, 512, 1024

Typical range of values: 0 ≤ Row Row Row Row Row row ≤ 32768 (lin)

Minimum increment: 1

Recommended increment: 1

Restriction: 0 <= Row && Row < height(Image)

ColumnColumnColumnColumnColumncolumn (input_control)  point.x(-array) HTupleHTupleHTupleVARIANTHtuple (integer) (int / long) (Hlong) (Hlong) (Hlong) (Hlong)

Column coordinates of pixels to be viewed.

Number of elements: Column == Row

Default value: 0

Suggested values: 0, 64, 128, 256, 512, 1024

Typical range of values: 0 ≤ Column Column Column Column Column column ≤ 32768 (lin)

Minimum increment: 1

Recommended increment: 1

Restriction: 0 <= Column && Column < width(Image)

GrayvalGrayvalGrayvalGrayvalGrayvalgrayval (output_control)  grayval(-array) HTupleHTupleHTupleVARIANTHtuple (real / integer) (double / int / long) (double / Hlong) (double / Hlong) (double / Hlong) (double / Hlong)

Gray values of indicated pixels.


If the state of the parameters is correct, the operator get_grayvalget_grayvalGetGrayvalget_grayvalGetGrayvalGetGrayval returns the value 2 (H_MSG_TRUE). The behavior in case of empty input (no input images available) is set via the operator 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.

Possible Predecessors



get_image_pointer1get_image_pointer1GetImagePointer1get_image_pointer1GetImagePointer1GetImagePointer1, get_grayval_interpolatedget_grayval_interpolatedGetGrayvalInterpolatedget_grayval_interpolatedGetGrayvalInterpolatedGetGrayvalInterpolated, get_grayval_contour_xldget_grayval_contour_xldGetGrayvalContourXldget_grayval_contour_xldGetGrayvalContourXldGetGrayvalContourXld

See also




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