public override object GetStretcher(int bandNo)
{
object stratcher = RgbStretcherFactory.GetStretcher("MWRIX.SWE");
if (stratcher == null)
{
stratcher = RgbStretcherFactory.CreateStretcher(enumDataType.Byte, 0, 255);
}
return(stratcher);
}
public override object GetStretcher(int bandNo)
{
if (bandNo == 5)
{
return(RgbStretcherFactory.CreateStretcher(enumDataType.Float, 0, 4));
}
else
{
return(base.GetStretcher(bandNo));
}
}
private object TryGetDefaultStretcher(IRasterBand band)
{
double minValue, maxValue;
if (_dataType == enumDataType.Byte)
{
minValue = 0;
maxValue = 255;
}
else
{
band.ComputeMinMax(out minValue, out maxValue, true, null);
}
return(RgbStretcherFactory.CreateStretcher(_dataType, minValue, maxValue));
}
private object[] GetStretcher(enumDataType dataType, RasterQuickStatResult[] resutls, float percent)
{
int bandCount = resutls.Length;
//x%像元临界个数
int criticalCount = (int)(percent * resutls[0].HistogramResult.PixelCount);
object[] sts = new object[bandCount];
//low
for (int i = 0; i < bandCount; i++)
{
//边界DN值
double lowValue = 0, heightValue = 0;
//累计个数
double accCount = 0;
int bucks = resutls[i].HistogramResult.ActualBuckets;
//lowValue
for (int k = 0; k < bucks; k++)
{
if (accCount > criticalCount)
{
break;
}
accCount += resutls[i].HistogramResult.Items[k];
lowValue = resutls[i].HistogramResult.MinDN + k * resutls[i].HistogramResult.Bin;
}
//HighValue
accCount = 0;
for (int k = bucks - 1; k >= 0; k--)
{
if (accCount > criticalCount)
{
break;
}
accCount += resutls[i].HistogramResult.Items[k];
heightValue = resutls[i].HistogramResult.MinDN + k * resutls[i].HistogramResult.Bin;
}
//
sts[i] = RgbStretcherFactory.CreateStretcher(dataType, lowValue, heightValue);
}
return(sts);
}