Merge pull request #1750 from LaurentBerger:oilpainting

* Oil painting effect

* license

* try auto

* Insert test

* template

* review

* indentation in namespace

* remove back to future

modules/xphoto/doc/xphoto.bib

@@ -14,3 +14,9 @@
   pages={1000--1008},
   year={2015}
 }
+
+@book{Holzmann1988,
+  title={Beyond Photography: The Digital Darkroom},
+  author={GerPublished by ard J. Holzmann},
+  publisher={Prentice Hall in 1988}
+}
\ No newline at end of file

modules/xphoto/include/opencv2/xphoto.hpp

@@ -50,4 +50,5 @@
 #include "xphoto/white_balance.hpp"
 #include "xphoto/dct_image_denoising.hpp"
 #include "xphoto/bm3d_image_denoising.hpp"
+#include "xphoto/oilpainting.hpp"
 #endif

modules/xphoto/include/opencv2/xphoto/oilpainting.hpp

+// 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_OIL_PAINTING_HPP__
+#define __OPENCV_OIL_PAINTING_HPP__
+
+#include <opencv2/core.hpp>
+#include <opencv2/imgproc.hpp>
+
+namespace cv
+{
+namespace xphoto
+{
+
+//! @addtogroup xphoto
+//! @{
+
+/** @brief oilPainting
+See the book @cite Holzmann1988 for details.
+@param src Input three-channel or one channel image (either CV_8UC3 or CV_8UC1)
+@param dst Output image of the same size and type as src.
+@param size neighbouring size is 2-size+1
+@param dynRatio image is divided by dynRatio before histogram processing
+@param code	color space conversion code(see ColorConversionCodes). Histogram will used only first plane
+*/
+CV_EXPORTS_W void oilPainting(InputArray src, OutputArray dst, int size, int dynRatio, int code);
+/** @brief oilPainting
+See the book @cite Holzmann1988 for details.
+@param src Input three-channel or one channel image (either CV_8UC3 or CV_8UC1)
+@param dst Output image of the same size and type as src.
+@param size neighbouring size is 2-size+1
+@param dynRatio image is divided by dynRatio before histogram processing
+*/
+CV_EXPORTS_W void oilPainting(InputArray src, OutputArray dst, int size, int dynRatio);
+//! @}
+}
+}
+
+#endif // __OPENCV_OIL_PAINTING_HPP__

modules/xphoto/samples/oil.cpp

+#include <opencv2/core.hpp>
+#include <opencv2/highgui.hpp>
+#include <opencv2/imgproc.hpp>
+#include <opencv2/xphoto.hpp>
+#include "opencv2/xphoto/oilpainting.hpp"
+#include <iostream>
+
+using namespace cv;
+using namespace std;
+
+static void TrackSlider(int , void *);
+static void addSlider(String sliderName, String windowName, int minSlider, int maxSlider, int valDefault, int *valSlider, void(*f)(int, void *), void *r);
+vector<int> colorSpace = { COLOR_BGR2GRAY,COLOR_BGR2HSV,COLOR_BGR2YUV,COLOR_BGR2XYZ };
+
+struct OilImage {
+    String winName = "Oil painting";
+    int size;
+    int dynRatio;
+    int colorSpace;
+    Mat img;
+};
+
+const String keys =
+"{Help h usage ? help  |     | Print this message   }"
+"{v                    | 0   | video index }"
+"{a                    | 700   | API index }"
+"{s                    | 10   | neighbouring size }"
+"{d                    | 1   | dynamic ratio }"
+"{c                    | 0   | color space }"
+"{@arg1                |     | file path}"
+;
+
+
+int main(int argc, char* argv[])
+{
+    CommandLineParser parser(argc, argv, keys);
+
+    if (parser.has("help"))
+    {
+        parser.printMessage();
+        return 0;
+    }
+    String filename = parser.get<String>(0);
+    OilImage p;
+    p.dynRatio = parser.get<int>("d");
+    p.size = parser.get<int>("s");
+    p.colorSpace = parser.get<int>("c");
+    if (p.colorSpace < 0 || p.colorSpace >= static_cast<int>(colorSpace.size()))
+    {
+        std::cout << "Color space must be >= 0 and <"<< colorSpace.size()<<"\n";
+        return EXIT_FAILURE;
+    }
+    if (!filename.empty())
+    {
+        p.img = imread(filename);
+        if (p.img.empty())
+        {
+            std::cout << "Check file path!\n";
+            return EXIT_FAILURE;
+        }
+        Mat dst;
+        xphoto::oilPainting(p.img, dst, p.size, p.dynRatio, colorSpace[p.colorSpace]);
+        imshow("oil painting effect", dst);
+        waitKey();
+        return 0;
+    }
+    VideoCapture v(parser.get<int>("v")+ parser.get<int>("a"));
+    v>> p.img;
+    p.winName="Oil Painting";
+    namedWindow(p.winName);
+    addSlider("DynRatio", p.winName, 1,127,p.dynRatio,&p.dynRatio, TrackSlider, &p);
+    addSlider("Size", p.winName, 1, 100, p.size, &p.size, TrackSlider, &p);
+    addSlider("ColorSpace", p.winName, 0, static_cast<int>(colorSpace.size()-1), p.colorSpace, &p.colorSpace, TrackSlider, &p);
+    while (waitKey(20) != 27)
+    {
+        v>>p.img;
+        imshow("Original", p.img);
+        TrackSlider(0, &p);
+        waitKey(10);
+    }
+    return 0;
+}
+
+void addSlider(String sliderName, String windowName, int minSlider, int maxSlider, int valDefault, int *valSlider, void(*f)(int, void *), void *r)
+{
+    createTrackbar(sliderName, windowName, valSlider, 1, f, r);
+    setTrackbarMin(sliderName, windowName, minSlider);
+    setTrackbarMax(sliderName, windowName, maxSlider);
+    setTrackbarPos(sliderName, windowName, valDefault);
+}
+
+void TrackSlider(int , void *r)
+{
+    OilImage *p = (OilImage *)r;
+    Mat dst;
+    p->img = p->img / p->dynRatio;
+    p->img = p->img*p->dynRatio;
+    xphoto::oilPainting(p->img, dst, p->size, p->dynRatio,colorSpace[p->colorSpace]);
+    if (!dst.empty())
+    {
+        imshow(p->winName, dst);
+    }
+}

modules/xphoto/src/oilpainting.cpp

+// 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 "opencv2/xphoto.hpp"
+#include <opencv2/core.hpp>
+#include <opencv2/imgproc.hpp>
+
+template<class T>
+class Vec3fTo {
+public :
+    cv::Vec3f a;
+    Vec3fTo(cv::Vec3f x) {
+        a = x;
+    };
+    T extract();
+    cv::Vec3f make(int);
+};
+
+template<>
+uchar Vec3fTo<uchar>::extract()
+{
+    return static_cast<uchar>(a[0]);
+}
+
+template<>
+cv::Vec3b Vec3fTo<cv::Vec3b>::extract()
+{
+    return a;
+}
+
+template<>
+cv::Vec3f Vec3fTo<uchar>::make(int x)
+{
+    return cv::Vec3f((a*x)/x);
+}
+
+template<>
+cv::Vec3f Vec3fTo<cv::Vec3b>::make(int x)
+{
+    return cv::Vec3f(static_cast<float>(static_cast<int>(a[0]*x)/x),
+        static_cast<float>(static_cast<int>(a[1] * x) / x),
+        static_cast<float>(static_cast<int>(a[2] * x) / x));
+}
+
+namespace cv
+{
+namespace xphoto
+{
+template<typename Type>
+class ParallelOilPainting : public ParallelLoopBody
+{
+private:
+    Mat & imgSrc;
+    Mat &dst;
+    Mat &imgLuminance;
+    int halfsize;
+    int dynRatio;
+
+public:
+    ParallelOilPainting<Type>(Mat& img, Mat &d, Mat &iLuminance, int r,int k) :
+        imgSrc(img),
+        dst(d),
+        imgLuminance(iLuminance),
+        halfsize(r),
+        dynRatio(k)
+    {}
+    virtual void operator()(const Range& range) const CV_OVERRIDE
+    {
+        std::vector<int> histogram(256);
+        std::vector<Vec3f> meanBGR(256);
+
+        for (int y = range.start; y < range.end; y++)
+        {
+            Type *vDst = dst.ptr<Type>(y);
+            for (int x = 0; x < imgSrc.cols; x++, vDst++)
+            {
+                if (x == 0)
+                {
+                    histogram.assign(256, 0);
+                    meanBGR.assign(256, Vec3f(0,0,0));
+                    for (int yy = -halfsize; yy <= halfsize; yy++)
+                    {
+                        if (y + yy >= 0 && y + yy < imgSrc.rows)
+                        {
+                            Type *vPtr = imgSrc.ptr<Type>(y + yy) + x - 0;
+                            uchar *uc = imgLuminance.ptr(y + yy) + x - 0;
+                            for (int xx = 0; xx <= halfsize; xx++, vPtr++, uc++)
+                            {
+                                if (x + xx >= 0 && x + xx < imgSrc.cols)
+                                {
+                                    histogram[*uc]++;
+                                    meanBGR[*uc] += Vec3fTo<Type>(*vPtr).make(dynRatio);
+                                }
+                            }
+                        }
+                    }
+
+                }
+                else
+                {
+                    for (int yy = -halfsize; yy <= halfsize; yy++)
+                    {
+                        if (y + yy >= 0 && y + yy < imgSrc.rows)
+                        {
+                            Type *vPtr = imgSrc.ptr<Type>(y + yy) + x - halfsize - 1;
+                            uchar *uc = imgLuminance.ptr(y + yy) + x - halfsize - 1;
+                            int xx = -halfsize - 1;
+                            if (x + xx >= 0 && x + xx < imgSrc.cols)
+                            {
+                                histogram[*uc]--;
+                                meanBGR[*uc] -= Vec3fTo<Type>(*vPtr).make(dynRatio);
+                            }
+                            vPtr = imgSrc.ptr<Type>(y + yy) + x + halfsize;
+                            uc = imgLuminance.ptr(y + yy) + x + halfsize;
+                            xx = halfsize;
+                            if (x + xx >= 0 && x + xx < imgSrc.cols)
+                            {
+                                histogram[*uc]++;
+                                meanBGR[*uc] += Vec3fTo<Type>(*vPtr).make(dynRatio);
+                            }
+                        }
+                    }
+                }
+                auto pos = distance(histogram.begin(), std::max_element(histogram.begin(), histogram.end()));
+                *vDst = Vec3fTo<Type>(meanBGR[pos] / histogram[pos]).extract();
+            }
+        }
+    }
+};
+
+void oilPainting(InputArray src, OutputArray dst, int size, int dynValue)
+{
+    oilPainting(src, dst, size, dynValue, COLOR_BGR2GRAY);
+}
+
+void oilPainting(InputArray _src, OutputArray _dst, int size, int dynValue,int code)
+{
+    CV_CheckType(_src.type(), _src.type() == CV_8UC1 || _src.type() == CV_8UC3, "only 1 or 3 channels (CV_8UC)");
+    CV_Assert(_src.kind() == _InputArray::MAT);
+    CV_Assert(size >= 1);
+    CV_CheckGT(dynValue , 0,"dynValue must be  0");
+    CV_CheckLT(dynValue, 128, "dynValue must less than 128 ");
+    Mat src = _src.getMat();
+    Mat lum,dst(_src.size(),_src.type());
+    if (src.type() == CV_8UC3)
+    {
+        cvtColor(_src, lum, code);
+        if (lum.channels() > 1)
+        {
+            extractChannel(lum, lum, 0);
+        }
+    }
+    else
+        lum = src.clone();
+    double dratio = 1 / double(dynValue);
+    lum.forEach<uchar>([=](uchar &pixel, const int * /*position*/) { pixel = saturate_cast<uchar>(cvRound(pixel * dratio)); });
+    if (_src.type() == CV_8UC1)
+    {
+        ParallelOilPainting<uchar> oilAlgo(src, dst, lum, size, dynValue);
+        parallel_for_(Range(0, src.rows), oilAlgo);
+    }
+    else
+    {
+        ParallelOilPainting<Vec3b> oilAlgo(src, dst, lum, size, dynValue);
+        parallel_for_(Range(0, src.rows), oilAlgo);
+    }
+    dst.copyTo(_dst);
+    dst = (dst  / dynValue) * dynValue;
+}
+}
+}

modules/xphoto/test/test_oil_painting.cpp

+// 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"
+
+namespace opencv_test { namespace {
+
+Mat testOilPainting(Mat imgSrc, int halfSize, int dynRatio, int colorSpace)
+{
+    vector<int> histogramme;
+    vector<Vec3f> moyenneRGB;
+    Mat dst(imgSrc.size(), imgSrc.type());
+    Mat lum;
+    if (imgSrc.channels() != 1)
+    {
+        cvtColor(imgSrc, lum, colorSpace);
+        if (lum.channels() > 1)
+        {
+            extractChannel(lum, lum, 0);
+        }
+    }
+    else
+        lum = imgSrc.clone();
+    lum = lum / dynRatio;
+    if (dst.channels() == 3)
+        for (int y = 0; y < imgSrc.rows; y++)
+        {
+            Vec3b *vDst = dst.ptr<Vec3b>(y);
+            for (int x = 0; x < imgSrc.cols; x++, vDst++) //for each pixel
+            {
+                Mat mask(lum.size(), CV_8UC1, Scalar::all(0));
+                Rect r(Point(x - halfSize, y - halfSize), Size(2 * halfSize + 1, 2 * halfSize + 1));
+                r = r & Rect(Point(0, 0), lum.size());
+                mask(r).setTo(255);
+                int histSize[] = { 256 };
+                float hranges[] = { 0, 256 };
+                const float* ranges[] = { hranges };
+                Mat hist;
+                int channels[] = { 0 };
+                calcHist(&lum, 1, channels, mask, hist, 1, histSize, ranges, true, false);
+                double maxVal = 0;
+                Point pMin, pMax;
+                minMaxLoc(hist, 0, &maxVal, &pMin, &pMax);
+                mask.setTo(0, lum != static_cast<int>(pMax.y));
+                Scalar v = mean(imgSrc, mask);
+                *vDst = Vec3b(static_cast<uchar>(v[0]), static_cast<uchar>(v[1]), static_cast<uchar>(v[2]));
+            }
+        }
+    else
+        for (int y = 0; y < imgSrc.rows; y++)
+        {
+            uchar *vDst = dst.ptr<uchar>(y);
+            for (int x = 0; x < imgSrc.cols; x++, vDst++) //for each pixel
+            {
+                Mat mask(lum.size(), CV_8UC1, Scalar::all(0));
+                Rect r(Point(x - halfSize, y - halfSize), Size(2 * halfSize + 1, 2 * halfSize + 1));
+                r = r & Rect(Point(0, 0), lum.size());
+                mask(r).setTo(255);
+                int histSize[] = { 256 };
+                float hranges[] = { 0, 256 };
+                const float* ranges[] = { hranges };
+                Mat hist;
+                int channels[] = { 0 };
+                calcHist(&lum, 1, channels, mask, hist, 1, histSize, ranges, true, false);
+                double maxVal = 0;
+                Point pMin, pMax;
+                minMaxLoc(hist, 0, &maxVal, &pMin, &pMax);
+                mask.setTo(0, lum != static_cast<int>(pMax.y));
+                Scalar v = mean(imgSrc, mask);
+                *vDst = static_cast<uchar>(v[0]);
+            }
+        }
+    return dst;
+}
+
+TEST(xphoto_oil_painting, regression)
+{
+    string folder = string(cvtest::TS::ptr()->get_data_path()) + "cv/inpaint/";
+    Mat orig = imread(folder+"exp1.png", IMREAD_COLOR);
+    ASSERT_TRUE(!orig.empty());
+    resize(orig, orig, Size(100, 100));
+    Mat dst1, dst2, dd;
+    xphoto::oilPainting(orig, dst1, 3, 5, COLOR_BGR2GRAY);
+    dst2 = testOilPainting(orig, 3, 5, COLOR_BGR2GRAY);
+    absdiff(dst1, dst2, dd);
+    vector<Mat> plane;
+    split(dd, plane);
+    for (auto p : plane)
+    {
+        double maxVal;
+        Point pIdx;
+        minMaxLoc(p, NULL, &maxVal, NULL, &pIdx);
+        ASSERT_LE(p.at<uchar>(pIdx), 2);
+    }
+    Mat orig2 = imread(folder + "exp1.png",IMREAD_GRAYSCALE);
+    ASSERT_TRUE(!orig2.empty());
+    resize(orig2, orig2, Size(100, 100));
+    Mat dst3, dst4, ddd;
+    xphoto::oilPainting(orig2, dst3, 3, 5, COLOR_BGR2GRAY);
+    dst4 = testOilPainting(orig2, 3, 5, COLOR_BGR2GRAY);
+    absdiff(dst3, dst4, ddd);
+    double maxVal;
+    Point pIdx;
+    minMaxLoc(ddd, NULL, &maxVal, NULL, &pIdx);
+    ASSERT_LE(ddd.at<uchar>(pIdx), 2);
+}
+
+}} // namespace

modules/xphoto/tutorials/oil_painting_effect.markdown

+Oil painting effect {#tutorial_xphoto_oil_painting_effect}
+===================================================
+
+Introduction
+------------
+Image is converted in a color space default color space COLOR_BGR2GRAY.
+For every pixel in the image a program calculated a histogram (first plane of color space) of the neighbouring of size 2*size+1.
+and assigned the value of the most frequently occurring value. The result looks almost like an oil painting. Parameter 4 of oilPainting is used to decrease image dynamic and hence increase oil painting effect.
+
+Example
+--------------------
+
+
+    @code{.cpp}
+    Mat img;
+    Mat dst;
+    img = imread("opencv/samples/data/baboon.jpg");
+    xphoto::oilPainting(img, dst, 10, 1, COLOR_BGR2Lab);
+    imshow("oil painting effect", dst);
+    @endcode
+
+    Original ![](images/baboon.jpg)
+    Oil painting effect ![](images/baboon_oil_painting_effect.jpg)