Add signal module with signal resampling function

modules/README.md

@@ -72,6 +72,8 @@ $ cmake -D OPENCV_EXTRA_MODULES_PATH=<opencv_contrib>/modules -D BUILD_opencv_<r
 
 - **saliency**: Saliency API -- Where humans would look in a scene. Has routines for static, motion and "objectness" saliency.
 
+- **signal**: Signal processing algorithms
+
 - **sfm**: Structure from Motion -- This module contains algorithms to perform 3d reconstruction from 2d images. The core of the module is a light version of Libmv.
 
 - **shape**: Shape Distance and Matching

modules/signal/CMakeLists.txt

@@ -0,0 +1,2 @@
+set(the_description "Signal processing algorithms")
+ocv_define_module(signal opencv_core WRAP python)

modules/signal/README.md

@@ -0,0 +1,4 @@
+Signal Processing algorithms
+================================================
+
+Signal resampling done with cubic interpolation and low-pass filtering

modules/signal/include/opencv2/signal.hpp

@@ -0,0 +1,17 @@
+// 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
+#ifndef OPENCV_SIGNAL_HPP
+#define OPENCV_SIGNAL_HPP
+
+/**
+* @defgroup signal Signal Processing
+* @{
+* This module includes signal processing algorithms.
+* @}
+*/
+
+#include "opencv2/core.hpp"
+#include "opencv2/signal/signal_resample.hpp"
+
+#endif

modules/signal/include/opencv2/signal/signal_resample.hpp

@@ -0,0 +1,32 @@
+// 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
+#ifndef OPENCV_SIGNAL_SIGNAL_RESAMPLE_HPP
+#define OPENCV_SIGNAL_SIGNAL_RESAMPLE_HPP
+
+#include <opencv2/core.hpp>
+
+namespace cv {
+namespace signal {
+
+//! @addtogroup signal
+//! @{
+
+/** @brief Signal resampling
+ *
+ * @param[in]  inputSignal              Array with input signal.
+ * @param[out] outSignal                Array with output signal
+ * @param[in]  inFreq                   Input signal frequency.
+ * @param[in]  outFreq                  Output signal frequency.
+ * Signal resampling implemented a cubic interpolation function and a filtering function based on Kaiser window and Bessel function, used to construct a FIR filter.
+ * Result is similar to `scipy.signal.resample`.
+
+Detail: https://en.wikipedia.org/wiki/Sample-rate_conversion
+*/
+CV_EXPORTS_W void resampleSignal(InputArray inputSignal, OutputArray outSignal, const int inFreq, const int outFreq);
+
+//! @}
+
+}
+}
+#endif

modules/signal/perf/perf_main.cpp

@@ -0,0 +1,6 @@
+// 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 "perf_precomp.hpp"
+
+CV_PERF_TEST_MAIN(signal)

modules/signal/perf/perf_precomp.hpp

@@ -0,0 +1,15 @@
+// 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.
+#ifndef __OPENCV_PERF_PRECOMP_HPP__
+#define __OPENCV_PERF_PRECOMP_HPP__
+
+#include "opencv2/ts.hpp"
+#include "opencv2/signal.hpp"
+
+namespace opencv_test {
+using namespace perf;
+using namespace cv::signal;
+}
+
+#endif

modules/signal/perf/perf_resample.cpp

@@ -0,0 +1,37 @@
+// 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 "perf_precomp.hpp"
+
+using namespace std;
+using namespace cv;
+using namespace perf;
+
+namespace opencv_test { namespace {
+
+typedef TestBaseWithParam< tuple<uint32_t, uint32_t, uint32_t> > TestResampleFunc;
+
+PERF_TEST_P( TestResampleFunc, resample_sin_signal,
+             testing::Combine(
+                testing::Values(1234U, 12345U, 123456U, 1234567U, 12345678U),
+                testing::Values(16000U, 32000U, 44100U, 48000U),
+                testing::Values(48000U, 44100U, 32000U, 16000U))
+)
+{
+    uint32_t sample_signal_size = GET_PARAM(0);
+    uint32_t inFreq = GET_PARAM(1);
+    uint32_t outFreq = GET_PARAM(2);
+
+    Mat1f sample_signal(Size(sample_signal_size,1U));
+    Mat1f outSignal(Size(1U, 1U));
+    for (uint32_t i = 0U; i < (uint32_t)sample_signal.cols; ++i)
+    {
+        sample_signal.at<float>(0, i) = sinf(float(i));
+    }
+    declare.in(sample_signal).out(outSignal);
+    TEST_CYCLE() resampleSignal(sample_signal, outSignal, inFreq, outFreq);
+    SANITY_CHECK_NOTHING();
+}
+
+}}

modules/signal/src/precomp.hpp

@@ -0,0 +1,10 @@
+// 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
+
+#ifndef __OPENCV_SIGNAL_PRECOMP__
+#define __OPENCV_SIGNAL_PRECOMP__
+
+#include <opencv2/core.hpp>
+
+#endif