From 759383c4a1067b36d60d7bf9f5a419dc33344539 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Du=C5=A1an=20Poizl?= <nou.spiro@gmail.com>
Date: Sat, 28 Sep 2019 13:05:07 +0200
Subject: [PATCH] Make median filter parallel

---
 imageselector.pro |  4 +++-
 loadrunable.cpp   | 13 +++++++++----
 rawimage.h        |  6 +++---
 3 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/imageselector.pro b/imageselector.pro
index fa187d7..b54c6cf 100644
--- a/imageselector.pro
+++ b/imageselector.pro
@@ -13,7 +13,9 @@ TEMPLATE = app
 
 CONFIG += c++11
 
-LIBS += -lraw -lexif -lcfitsio
+QMAKE_CXXFLAGS += -fopenmp
+
+LIBS += -lraw -lexif -lcfitsio -fopenmp
 
 SOURCES += main.cpp\
         mainwindow.cpp \
diff --git a/loadrunable.cpp b/loadrunable.cpp
index acbfc96..b5e4b0c 100644
--- a/loadrunable.cpp
+++ b/loadrunable.cpp
@@ -26,7 +26,7 @@ void loadExifEntry(ImageInfoData &info, ExifContent *content, ExifTag tag)
     }
 }
 
-void drawPeaks(QImage &img, const std::vector<Peak> &peaks, bool half)
+void drawPeaks(QImage &img, const std::vector<Peak> &peaks)
 {
     QPixmap pix = QPixmap::fromImage(img);
     QPainter painter(&pix);
@@ -222,9 +222,11 @@ void LoadRunable::run()
 
     QImage img;
     RawImageAbs *rawImage = nullptr;
+    bool raw = false;
     if(m_file.endsWith(".CR2", Qt::CaseInsensitive))
     {
         loadRAW(m_file, info, m_analyzeLevel != None ? &rawImage : nullptr, &img);
+        raw = true;
     }
     else if(m_file.endsWith(".FIT", Qt::CaseInsensitive))
     {
@@ -244,7 +246,7 @@ void LoadRunable::run()
         }
     }
 
-    if(m_analyzeLevel >= Statistics)
+    if(rawImage && m_analyzeLevel >= Statistics)
     {
         uint64_t mean, median, min, max;
         double stdDev;
@@ -258,10 +260,13 @@ void LoadRunable::run()
         if(m_analyzeLevel >= Peaks)
         {
             std::vector<Peak> peaks;
-            rawImage->quarter();
+            if(raw) {
+                rawImage->quarter();
+                qDebug() << "quarter" << timer.restart();
+            }
             rawImage->medianFilter();
             int numPeaks = rawImage->findPeaks(median+stdDev, 20, peaks);
-            drawPeaks(img, peaks, true);
+            drawPeaks(img, peaks);
             info.append(StringPair(QObject::tr("Peaks"), QString::number(numPeaks)));
             info.append(StringPair(QObject::tr("Peaks draw"), QString::number(peaks.size())));
         }
diff --git a/rawimage.h b/rawimage.h
index db2c34e..76d616b 100644
--- a/rawimage.h
+++ b/rawimage.h
@@ -169,7 +169,7 @@ public:
     {
         std::vector<T> tmp;
         tmp.resize(m_width*m_height);
-        size_t d=0;
+        #pragma omp parallel for
         for(uint32_t y=0;y<m_height;y++)
         {
             for(uint32_t x=0;x<m_width;x++)
@@ -177,8 +177,8 @@ public:
                 T array[9] = { pixel(x-1, y-1), pixel(x, y-1), pixel(x+1, y-1),
                              pixel(x-1, y), pixel(x, y), pixel(x+1, y),
                              pixel(x-1, y+1), pixel(x, y+1), pixel(x+1, y+1)};
-                std::partial_sort(std::begin(array), array+5, std::end(array));
-                tmp[d++] = array[4];
+                std::nth_element(std::begin(array), array+4, std::end(array));
+                tmp[y*m_width+x] = array[4];
             }
         }
         m_img = std::move(tmp);