add curve compensation

src/uvosunwrap/curve.h

@@ -0,0 +1,61 @@
+/**
+* Lubricant Detecter
+* Copyright (C) 2021 Carl Klemm
+*
+* This program is free software; you can redistribute it and/or
+* modify it under the terms of the GNU General Public License
+* version 3 as published by the Free Software Foundation.
+*
+* This program 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 this program; if not, write to the
+* Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+* Boston, MA  02110-1301, USA.
+*/
+
+#pragma once
+#include <opencv2/core/ocl.hpp>
+#include <assert.h>
+
+float applyCurve(float in, cv::Mat curve)
+{
+	assert(curve.type() == CV_32FC1);
+	assert(curve.rows == 2);
+
+	float* keys   = curve.ptr<float>(0);
+	float* values = curve.ptr<float>(1);
+	
+	if(in < keys[0])
+		return values[0];
+		
+
+	for(int i = 1; i < curve.cols; ++i)
+	{		
+		if(in < keys[i])
+		{
+			double slope = (values[i] - (double)values[i-1])/(keys[i] - keys[i-1]);
+			return (in-keys[i-1])*slope+values[i-1];
+		}
+	}
+	return values[curve.cols-1];
+}
+
+void applyCurve(cv::Mat image, cv::Mat curve)
+{
+	assert(image.type() == CV_32FC1);
+	assert(curve.type() == CV_32FC1);
+	assert(curve.rows == 2);
+	
+	for(int y = 0; y < image.rows; y++)
+	{
+		float* col = image.ptr<float>(y);
+		for(int x = 0; x < image.cols; ++x)
+		{
+			col[x]=applyCurve(col[x], curve);
+		}
+	}
+}