text: // This file is part of OpenCV project.
  // It is subject to the license terms in the LICENSE file found in the top-level directory
  // of this distribution and at http://opencv.org/license.html.
  
  #include "test_precomp.hpp"
  
  #define TEST_CASE_NAME CV_Quality_SSIM
  
  namespace opencv_test
  {
  namespace quality_test
  {
  
  // ssim per channel
  const cv::Scalar
      SSIM_EXPECTED_1 = { .1501 }
      , SSIM_EXPECTED_2 = { .7541, .7742, .8095 }
      ;
  
  // static method
  TEST(TEST_CASE_NAME, static_)
  {
      std::vector<cv::Mat> qMats = {};
      quality_expect_near(quality::QualitySSIM::compute(get_testfile_1a(), get_testfile_1a(), qMats), cv::Scalar(1.)); // ref vs ref == 1.
      EXPECT_EQ(qMats.size(), 1U );
  }
  
  // single channel, with/without opencl
  TEST(TEST_CASE_NAME, single_channel)
  {
      auto fn = []() { quality_test(quality::QualitySSIM::create(get_testfile_1a()), get_testfile_1b(), SSIM_EXPECTED_1); };
      OCL_OFF(fn());
      OCL_ON(fn());
  }
  
  // multi-channel
  TEST(TEST_CASE_NAME, multi_channel)
  {
      quality_test(quality::QualitySSIM::create(get_testfile_2a()), get_testfile_2b(), SSIM_EXPECTED_2);
  }
  
  // multi-frame test
  TEST(TEST_CASE_NAME, multi_frame)
  {
      // result == average of all frames
      cv::Scalar expected;
      cv::add(SSIM_EXPECTED_1, SSIM_EXPECTED_2, expected);
      expected /= 2.;
  
      quality_test(quality::QualitySSIM::create(get_testfile_1a2a()), get_testfile_1b2b(), expected, 2U );
  }
  
  // internal a/b test
  /*
  TEST(TEST_CASE_NAME, performance)
  {
      auto ref = get_testfile_1a();
      auto cmp = get_testfile_1b();
      quality_performance_test("SSIM", [&]() { cv::quality::QualitySSIM::compute(ref, cmp, cv::noArray()); });
  }
  */
  }
  } // namespace