Added entropy operation

app/Operations/EntropyOp.cpp

+/*
+ * Copyright 2011-2012 INSA Rennes
+ *
+ * This file is part of EIImage.
+ *
+ * EIImage is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * EIImage is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with EIImage.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "EntropyOp.h"
+
+#include "../Tools.h"
+#include <Image.h>
+
+using namespace std;
+using namespace imagein;
+
+EntropyOp::EntropyOp() : Operation(Tools::tr("Calcul d'entropie").toStdString())
+{
+}
+
+void EntropyOp::operator()(const imagein::Image* image, const std::map<const imagein::Image*, std::string>&) {
+
+    double entropy = 0.;
+    for(unsigned int c = 0; c < image->getNbChannels(); ++c) {
+        Histogram histo = image->getHistogram(c);
+        for(int i = 0; i < 256; ++i) {
+            if(histo[i] > 0) {
+                double p = (double)histo[i] / image->getWidth() /image->getHeight();
+                entropy +=  p * log(p);
+            }
+        }
+    }
+    entropy = - entropy / log(2);
+    outText(Tools::tr("Entropy of the image = %1").arg(entropy).toStdString());
+
+}
+
+bool EntropyOp::needCurrentImg() const {
+    return true;
+}

app/Operations/EntropyOp.h

+/*
+ * Copyright 2011-2012 INSA Rennes
+ *
+ * This file is part of EIImage.
+ *
+ * EIImage is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * EIImage is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with EIImage.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef ENTROPYOP_H
+#define ENTROPYOP_H
+
+#include <Operation.h>
+
+class EntropyOp : public Operation
+{
+public:
+    EntropyOp();
+
+    void operator()(const imagein::Image*, const std::map<const imagein::Image*, std::string>&);
+
+    bool needCurrentImg() const;
+};
+
+#endif // ENTROPYOP_H