Java中带有openCV的matchTemplate [英] matchTemplate with openCV in java

问题描述

我有这样的代码:

Mat img = Highgui.imread(inFile);
Mat templ = Highgui.imread(templateFile);
int result_cols = img.cols() - templ.cols() + 1;
int result_rows = img.rows() - templ.rows() + 1;
Mat result = new Mat(result_rows, result_cols, CvType.CV_32FC1);
Imgproc.matchTemplate(img, templ, result, Imgproc.TM_CCOEFF);
/////Core.normalize(result, result, 0, 1, Core.NORM_MINMAX, -1, new Mat());
for (int i = 0; i < result_rows; i++)
for (int j = 0; j < result_cols; j++) 
  if(result.get(i, j)[0]>?)

     //match!

我需要解析输入图像以查找模板图像的多次出现.我想要这样的结果:

I need to parse the input image to find multiple occurrencies of the template image. I want to have a result like this:

result[0][0]= 15%
result[0][1]= 17%
result[x][y]= 47%

如果我使用TM_COEFF，则所有结果均为[-xxxxxxxx.xxx，+ xxxxxxxx.xxx]

If i use TM_COEFF all results are [-xxxxxxxx.xxx,+xxxxxxxx.xxx]

如果我使用TM_SQDIFF，则所有结果均为xxxxxxxx.xxx

If i use TM_SQDIFF all results are xxxxxxxx.xxx

如果我使用TM_CCORR，则所有结果均为xxxxxxxx.xxx

If i use TM_CCORR all results are xxxxxxxx.xxx

如何检测匹配或不匹配? if的正确条件是什么? 如果我将矩阵归一化，则应用程序会将值设置为1，并且我将无法检测到模板是否未存储到图像中(全部不匹配).

How can i detect a match or a mismatch? What is the right condition into the if? If i normalized the matrix the application set a value to 1 and i can't detect if the template isn't stored into the image (all mismatch).

预先感谢

推荐答案

您可以在方法名称后附加"_NORMED"(例如，在C ++中为CV_TM_COEFF_NORMED；在Java中可能略有不同)，以获取适合您目的的值

You can append "_NORMED" to the method names (For instance: CV_TM_COEFF_NORMED in C++; could be slightly different in Java) to get a sensible value for your purpose.

明智"是指您将获得0到1范围内的值，该值可以乘以100以达到您的目的.

By 'sensible', I mean that you will get values in the range of 0 to 1 which can be multiplied by 100 for your purpose.

注意:对于CV_TM_SQDIFF_NORMED，它将在-1到0的范围内，并且您必须从1中减去该值才能理解它，因为在此方法中使用的是最低值.

Note: For CV_TM_SQDIFF_NORMED, it will be in the range -1 to 0, and you will have to subtract the value from 1 in order to make sense of it, because the lowest value if used in this method.

提示:您可以使用Java的minMaxLoc()等效项来获取最小值和最大值.与matchtemplate结合使用时，此功能非常有用. 我相信位于类Core内的"minMaxLoc".

Tip: you can use the java equivalent of minMaxLoc() in order to get the minimum and maximum values. It's very useful when used in conjunction with matchtemplate. I believe 'minMaxLoc' that is located inside the class Core.

这是一个C ++实现:

Here's a C++ implementation:

matchTemplate( input_mat, template_mat, result_mat, method_NORMED );

double minVal, maxVal; 

double percentage;

Point minLoc; Point maxLoc;

minMaxLoc( result, &minVal, &maxVal, &minLoc, &maxLoc, Mat() );
if( method_NORMED == CV_TM_SQDIFF_NORMED )
{
   percentage=1-minVal;
}
else
{
   percentage=maxVal;
}

有用的C ++文档: 匹配模板描述以及可用方法: http://docs.opencv.org/modules /imgproc/doc/object_detection.html MinMaxLoc文档: http://docs.opencv.org/modules/core /doc/operations_on_arrays.html?highlight=minmaxloc#minmaxloc

Useful C++ docs: Match template description along with available methods: http://docs.opencv.org/modules/imgproc/doc/object_detection.html MinMaxLoc documentation: http://docs.opencv.org/modules/core/doc/operations_on_arrays.html?highlight=minmaxloc#minmaxloc

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