Adds Crop and Watermark mutations

DescriptorManager.cpp

@@ -20,12 +20,13 @@ DescriptorManager::DescriptorManager(const fs::path & image_path) {
 	descriptor_types[0] = new averageColor();
 
 	mutators[0] = new Grayscale();
-	mutators[1] = new Flip();
+	mutators[1] = new Crop();
 	mutators[2] = new Flop();
 	mutators[3] = new JPEG();
 	mutators[4] = new LowQ();
 	mutators[5] = new Hue();
 	mutators[6] = new Brighten();
+	mutators[7] = new Watermark();
 }
 
 //No need to call destructor.. yet?

DescriptorManager.h

@@ -35,7 +35,7 @@ public:
 	void outputRank(string imagename, int method);
 private:
 	static const int numDescriptors = 8; 
-	static const int numMutations = 7;
+	static const int numMutations = 8;
 	//TODO: automagically update this?
 
 	bool initialized = false;

Mutation.h

@@ -102,3 +102,40 @@ public:
 		return "Brighten";
 	}
 };
+
+//shaves off some pixels from the bottomright edge of the image
+class Crop : public Mutation {
+public:
+	Image * getMutated(Image* img) {
+		Image* mut = new Image(*img);
+		ssize_t n = mut->rows();
+		ssize_t m = mut->columns();
+		float shave = 0.1;
+		n *= 1.0 - shave;
+		m *= 1.0 - shave;
+		mut->crop(Geometry(m, n, 0, 0));
+		return mut;
+	}
+	string ToString() {
+		return "Crop";
+	}
+};
+
+//Adds a logo to the top-left corner of the image
+class Watermark : public Mutation {
+public:
+	Watermark() {
+		watermark = new Image;
+		watermark->read("watermark.png");
+	}
+	Image * getMutated(Image* img) {
+		Image* mut = new Image(*img);
+		mut->composite(*watermark, "+10+10", OverCompositeOp);
+		return mut;
+	}
+	string ToString() {
+		return "Watermark";
+	}
+private:
+	Image* watermark;
+};