corner_responsecorner_responseCornerResponseCornerResponsecorner_response (算子)

名称

corner_responsecorner_responseCornerResponseCornerResponsecorner_response — 在图像中搜索角落。

签名

描述

算子 corner_responsecorner_responseCornerResponseCornerResponseCornerResponsecorner_response extracts gray value corners in an image. The formula for the calculation of the response is: where I is the input image and R the output image of the filter. The operator gauss_imagegauss_imageGaussImageGaussImageGaussImagegauss_image is used for smoothing (W), the operator sobel_ampsobel_ampSobelAmpSobelAmpSobelAmpsobel_amp is used for calculating the derivative。

The corner response function is invariant with regard to rotation. In order to achieve a suitable dependency of the function R(x,y) on the local gradient, the parameter WeightWeightWeightWeightweightweight must be set to 0.04. With this, only gray value corners will return positive values for R(x,y), while straight edges will receive negative values. The output image type is identical to the input image type. Therefore, the negative output values are set to 0 if byte images are used as input images. If this is not desired, the input image should be converted into a real or int2 image with convert_image_typeconvert_image_typeConvertImageTypeConvertImageTypeConvertImageTypeconvert_image_type。

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）。
• 在元组级别上自动并行化。
• 在通道级别上自动并行化。
• 在域级别上自动并行化。

参数

示例（C）

read_image(&Fabrik,"fabrik");
corner_response(Fabrik,&CornerResponse,3,0.04);
local_max(CornerResponse,&LocalMax);
disp_image(Fabrik,WindowHandle);
set_color(WindowHandle,"red");
disp_region(LocalMax,WindowHandle);

可能的后继

local_maxlocal_maxLocalMaxLocalMaxLocalMaxlocal_max, thresholdthresholdThresholdThresholdThresholdthreshold

另见

gauss_filtergauss_filterGaussFilterGaussFilterGaussFiltergauss_filter, sobel_ampsobel_ampSobelAmpSobelAmpSobelAmpsobel_amp, convert_image_typeconvert_image_typeConvertImageTypeConvertImageTypeConvertImageTypeconvert_image_type

参考文献

C.G. Harris, M.J. Stephens, “A combined corner and edge detector”'; Proc. of the 4th Alvey Vision Conference; August 1988; pp. 147-152.
H. Breit, “Bestimmung der Kameraeigenbewegung und Gewinnung von Tiefendaten aus monokularen Bildfolgen”; Diplomarbeit am Lehrstuhl für Nachrichtentechnik der TU München; 30. September 1990.

模块

基础