예제 #1
0
        private static void CalculateMinMaxCut(OSGeo.GDAL.Band rasterBand, double minPercentage, double maxPercentage, out int minCutValue, out int maxCutValue)
        {
            double[] minMax = new double[2];
            rasterBand.ComputeRasterMinMax(minMax, 0);
            int min = (int)minMax[0];
            int max = (int)minMax[1];

            int[] histogram = new int[max - min];
            rasterBand.GetHistogram(min, max, max - min, histogram, 1, 0, ProgressFunc, "");

            int totalPixels = 0;

            for (int bucket = 0; bucket < histogram.Length; ++bucket)
            {
                totalPixels += histogram[bucket];
            }

            double minCut = totalPixels * minPercentage;

            minCutValue = int.MaxValue;
            bool minCutSet = false;

            double maxCut = totalPixels * maxPercentage;

            maxCutValue = 0;
            bool maxCutSet = false;

            int pixelCount = 0;

            for (int bucket = 0; bucket < histogram.Length; ++bucket)
            {
                pixelCount += histogram[bucket];
                if (pixelCount >= minCut && !minCutSet)
                {
                    minCutValue = bucket + min;
                    minCutSet   = true;
                }
                if (pixelCount >= maxCut && !maxCutSet)
                {
                    maxCutValue = bucket + min;
                    maxCutSet   = true;
                }
            }
        }