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Improve the documentation.
Add demo code for cv::reduce, cv::merge and cv::split.
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‎modules/core/include/opencv2/core.hpp

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@@ -847,6 +847,13 @@ obtained. For example, the function can be used to compute horizontal and vertic
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raster image. In case of REDUCE_MAX and REDUCE_MIN , the output image should have the same type as the source one.
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In case of REDUCE_SUM and REDUCE_AVG , the output may have a larger element bit-depth to preserve accuracy.
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And multi-channel arrays are also supported in these two reduction modes.
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The following code demonstrates its usage for a single channel matrix.
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@snippet snippets/core_reduce.cpp example
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And the following code demonstrates its usage for a two-channel matrix.
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@snippet snippets/core_reduce.cpp example2
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@param src input 2D matrix.
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@param dst output vector. Its size and type is defined by dim and dtype parameters.
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@param dim dimension index along which the matrix is reduced. 0 means that the matrix is reduced to
@@ -866,6 +873,10 @@ elements of i-th input array are treated as mv[i].channels()-element vectors.
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The function cv::split does the reverse operation. If you need to shuffle channels in some other
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advanced way, use cv::mixChannels.
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The following example shows how to merge 3 single channel matrices into a single 3-channel matrix.
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@snippet snippets/core_merge.cpp example
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@param mv input array of matrices to be merged; all the matrices in mv must have the same
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size and the same depth.
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@param count number of input matrices when mv is a plain C array; it must be greater than zero.
@@ -889,6 +900,10 @@ The function cv::split splits a multi-channel array into separate single-channel
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\f[\texttt{mv} [c](I) = \texttt{src} (I)_c\f]
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If you need to extract a single channel or do some other sophisticated channel permutation, use
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mixChannels .
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The following example demonstrates how to split a 3-channel matrix into 3 single channel matrices.
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@snippet snippets/core_split.cpp example
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@param src input multi-channel array.
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@param mvbegin output array; the number of arrays must match src.channels(); the arrays themselves are
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reallocated, if needed.

‎modules/ts/include/opencv2/ts.hpp

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@@ -392,22 +392,22 @@ class CV_EXPORTS TS
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FAIL_MEMORY_CORRUPTION_BEGIN=-7,
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FAIL_MEMORY_CORRUPTION_END=-8,
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// the tested function (or test ifself) do not deallocate some memory
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// the tested function (or test itself) do not deallocate some memory
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FAIL_MEMORY_LEAK=-9,
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// the tested function returned invalid object, e.g. matrix, containing NaNs,
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// structure with NULL or out-of-range fields (while it should not)
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FAIL_INVALID_OUTPUT=-10,
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// the tested function returned valid object, but it does not match to
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// the tested function returned valid object, but it does not match
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// the original (or produced by the test) object
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FAIL_MISMATCH=-11,
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// the tested function returned valid object (a single number or numerical array),
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// but it differs too much from the original (or produced by the test) object
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FAIL_BAD_ACCURACY=-12,
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// the tested function hung. Sometimes, can be determined by unexpectedly long
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// the tested function hung. Sometimes, it can be determined by unexpectedly long
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// processing time (in this case there should be possibility to interrupt such a function
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FAIL_HANG=-13,
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@@ -448,7 +448,7 @@ class CV_EXPORTS TS
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std::vector<std::string> data_search_subdir;
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protected:
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// these are allocated within a test to try keep them valid in case of stack corruption
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// these are allocated within a test to try to keep them valid in case of stack corruption
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RNG rng;
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// information about the current test

‎samples/cpp/tutorial_code/snippets/core_merge.cpp

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/**
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* @file core_merge.cpp
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* @brief It demonstrates the usage of cv::merge.
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*
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* It shows how to merge 3 single channel matrices into a 3-channel matrix.
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*
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* @author KUANG Fangjun
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* @date August 2017
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*/
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#include <iostream>
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#include <opencv2/core.hpp>
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using namespace std;
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using namespace cv;
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int main()
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{
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//! [example]
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Mat m1 = (Mat_<uchar>(2,2) << 1,4,7,10);
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Mat m2 = (Mat_<uchar>(2,2) << 2,5,8,11);
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Mat m3 = (Mat_<uchar>(2,2) << 3,6,9,12);
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Mat channels[3] = {m1, m2, m3};
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Mat m;
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merge(channels, 3, m);
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/*
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m =
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[ 1, 2, 3, 4, 5, 6;
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7, 8, 9, 10, 11, 12]
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m.channels() = 3
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*/
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//! [example]
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return 0;
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}

‎samples/cpp/tutorial_code/snippets/core_reduce.cpp

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/**
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* @file core_reduce.cpp
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* @brief It demonstrates the usage of cv::reduce .
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*
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* It shows how to compute the row sum, column sum, row average,
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* column average, row minimum, column minimum, row maximum
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* and column maximum of a cv::Mat.
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*
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* @author KUANG Fangjun
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* @date August 2017
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*/
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#include <iostream>
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#include <opencv2/core.hpp>
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using namespace std;
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using namespace cv;
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int main()
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{
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{
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//! [example]
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Mat m = (Mat_<uchar>(3,2) << 1,2,3,4,5,6);
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Mat col_sum, row_sum;
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reduce(m, col_sum, 0, CV_REDUCE_SUM, CV_32F);
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reduce(m, row_sum, 1, CV_REDUCE_SUM, CV_32F);
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/*
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m =
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[ 1, 2;
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3, 4;
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5, 6]
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col_sum =
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[9, 12]
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row_sum =
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[3;
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7;
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11]
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*/
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//! [example]
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Mat col_average, row_average, col_min, col_max, row_min, row_max;
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reduce(m, col_average, 0, CV_REDUCE_AVG, CV_32F);
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cout << "col_average =\n" << col_average << endl;
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reduce(m, row_average, 1, CV_REDUCE_AVG, CV_32F);
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cout << "row_average =\n" << row_average << endl;
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reduce(m, col_min, 0, CV_REDUCE_MIN, CV_8U);
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cout << "col_min =\n" << col_min << endl;
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reduce(m, row_min, 1, CV_REDUCE_MIN, CV_8U);
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cout << "row_min =\n" << row_min << endl;
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reduce(m, col_max, 0, CV_REDUCE_MAX, CV_8U);
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cout << "col_max =\n" << col_max << endl;
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reduce(m, row_max, 1, CV_REDUCE_MAX, CV_8U);
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cout << "row_max =\n" << row_max << endl;
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/*
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col_average =
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[3, 4]
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row_average =
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[1.5;
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3.5;
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5.5]
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col_min =
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[ 1, 2]
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row_min =
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[ 1;
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3;
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5]
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col_max =
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[ 5, 6]
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row_max =
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[ 2;
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4;
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6]
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*/
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}
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{
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//! [example2]
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// two channels
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char d[] = {1,2,3,4,5,6};
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Mat m(3, 1, CV_8UC2, d);
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Mat col_sum_per_channel;
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reduce(m, col_sum_per_channel, 0, CV_REDUCE_SUM, CV_32F);
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/*
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col_sum_per_channel =
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[9, 12]
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*/
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//! [example2]
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}
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return 0;
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}

‎samples/cpp/tutorial_code/snippets/core_split.cpp

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/**
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* @file core_split.cpp
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* @brief It demonstrates the usage of cv::split .
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*
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* It shows how to split a 3-channel matrix into a 3 single channel matrices.
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*
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* @author KUANG Fangjun
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* @date August 2017
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*/
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#include <iostream>
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#include <opencv2/core.hpp>
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using namespace std;
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using namespace cv;
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int main()
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{
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//! [example]
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char d[] = {1,2,3,4,5,6,7,8,9,10,11,12};
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Mat m(2, 2, CV_8UC3, d);
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Mat channels[3];
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split(m, channels);
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/*
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channels[0] =
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[ 1, 4;
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7, 10]
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channels[1] =
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[ 2, 5;
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8, 11]
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channels[2] =
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[ 3, 6;
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9, 12]
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*/
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//! [example]
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return 0;
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}

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