message: imgproc(perf): update getPerspectiveTransform perf test
  Function is very fast, so 0.000 ms results are useless.
  1000 runs requires 25ms on i7-6700K.
diff: @@ -271,7 +271,7 @@ void update_map(const Mat& src, Mat& map_x, Mat& map_y, const int remapMode )
  }
  }
  -PERF_TEST(Transform, getPerspectiveTransform)
  +PERF_TEST(Transform, getPerspectiveTransform_1000)
  {
  unsigned int size = 8;
  Mat source(1, size/2, CV_32FC2);
  @@ -280,12 +280,14 @@ PERF_TEST(Transform, getPerspectiveTransform)
  declare.in(source, destination, WARMUP_RNG);
  - TEST_CYCLE()
  + PERF_SAMPLE_BEGIN()
  + for (int i = 0; i < 1000; i++)
  {
  transformCoefficient = getPerspectiveTransform(source, destination);
  }
  + PERF_SAMPLE_END()
  - SANITY_CHECK(transformCoefficient, 1e-5);
  + SANITY_CHECK_NOTHING();
  }
  } // namespace
  