get_grayvalT_get_grayvalGetGrayvalGetGrayvalget_grayval (算子)

名称

get_grayvalT_get_grayvalGetGrayvalGetGrayvalget_grayval — 访问图像对象的灰度值。

签名

描述

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

注意

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_grayvalGetGrayvalGetGrayvalGetGrayvalget_grayval produces quite some overhead. Typically, it is used to get single gray values of an image (e.g., get_mpositionget_mpositionGetMpositionGetMpositionGetMpositionget_mposition followed by get_grayvalget_grayvalGetGrayvalGetGrayvalGetGrayvalget_grayval). 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_pointer1GetImagePointer1GetImagePointer1GetImagePointer1get_image_pointer1 and to directly use the C or C++ interface for integrating own procedures.

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）。
• 未采用并行化处理。

参数

结果

If the state of the parameters is correct, the operator get_grayvalget_grayvalGetGrayvalGetGrayvalGetGrayvalget_grayval 返回值 2 ( H_MSG_TRUE )。当输入为空（无可用输入图像）时可设置行为通过算子 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。

可能的前趋

read_imageread_imageReadImageReadImageReadImageread_image

替代

get_image_pointer1get_image_pointer1GetImagePointer1GetImagePointer1GetImagePointer1get_image_pointer1, get_grayval_interpolatedget_grayval_interpolatedGetGrayvalInterpolatedGetGrayvalInterpolatedGetGrayvalInterpolatedget_grayval_interpolated, get_grayval_contour_xldget_grayval_contour_xldGetGrayvalContourXldGetGrayvalContourXldGetGrayvalContourXldget_grayval_contour_xld

另见

set_grayvalset_grayvalSetGrayvalSetGrayvalSetGrayvalset_grayval

模块

基础