private void SelectMode(StretchModeItem mode)
{
_suspend = true;
stretchModes.SelectedIndex = StretchModes.Select(m => m.Tag).IndexOf(mode.Stretch);
horizontalModes.SelectedIndex = HorizontalAlignments.Select(m => m.Tag).IndexOf(mode.HorizontalAlignment);
verticalModes.SelectedIndex = VerticalAlignments.Select(m => m.Tag).IndexOf(mode.VerticalAlignment);
_suspend = false;
OnSelectionChanged(null, null);
}
private IEnumerable <StretchModeItem> GetAllModes()
{
var index = 0;
foreach (var stretch in StretchModes.Select(m => m.Tag).OfType <Stretch>())
{
foreach (var horizontalAlignment in HorizontalAlignments.Select(m => m.Tag).OfType <HorizontalAlignment>())
{
foreach (var verticalAlignment in VerticalAlignments.Select(m => m.Tag).OfType <VerticalAlignment>())
{
yield return(new StretchModeItem(index++, stretch, horizontalAlignment, verticalAlignment));
}
}
}
}
/// <summary>
/// 按指定宽高和拉伸方法重采样数据集至Bitmap。
/// </summary>
/// <param name="InputImg">影像对象。</param>
/// <param name="Width">重采样宽度。</param>
/// <param name="Height">重采样高度。</param>
/// <param name="StretchMode">拉伸模式。</param>
/// <returns></returns>
public static Bitmap GetBitmap(Img InputImg, int Width, int Height, StretchModes StretchMode = StretchModes.No_stretch)
{
if (StretchMode < 0 || (int)StretchMode > 10)
{
throw new ArgumentOutOfRangeException("拉伸模式取值超出范围。");
}
Bitmap bitmap = new Bitmap(Width, Height, PixelFormat.Format32bppRgb);
ResetStretchInfo(InputImg); //或许需要重设一下拉伸端点。
#region 灰度图
if (InputImg.IsGrayscale)
{
double BandMin = InputImg.Min[0];
double BandMax = InputImg.Max[0];
Band band = InputImg.GDALDataset.GetRasterBand(1);
double[] r = new double[Width * Height];
band.ReadRaster(0, 0, InputImg.Width, InputImg.Height, r, Width, Height, 0, 0);
switch (StretchMode)
{
case StretchModes.No_stretch:
{
//无拉伸
for (int i = 0; i < Width; i++)
{
for (int j = 0; j < Height; j++)
{
if (r[i + j * Width] < 0)
{
bitmap.SetPixel(i, j, InputImg.Colortable[0]);
continue;
}
if (r[i + j * Width] > 255)
{
bitmap.SetPixel(i, j, InputImg.Colortable[255]);
continue;
}
bitmap.SetPixel(i, j, InputImg.Colortable[(byte)r[i + j * Width]]);
}
}
break;
}
case StretchModes.Linear:
case StretchModes.Linear_1:
case StretchModes.Linear_2:
case StretchModes.Linear_5:
case StretchModes.CustomLinear:
{
//线性
for (int i = 0; i < Width; i++)
{
for (int j = 0; j < Height; j++)
{
bitmap.SetPixel(i, j, InputImg.Colortable[LinearStretch(r[i + j * Width], InputImg.StretchInfo[0].Item1, InputImg.StretchInfo[0].Item2)]);
}
}
break;
}
case StretchModes.Equalization:
{
//直方图均衡
for (int i = 0; i < Width; i++)
{
for (int j = 0; j < Height; j++)
{
bitmap.SetPixel(i, j, InputImg.Colortable[EqualizationStretch(r[i + j * Width], InputImg.CumulativeProbability[0], InputImg.Min[0], InputImg.Max[0])]);
}
}
break;
}
case StretchModes.Gaussion:
{
//高斯
for (int i = 0; i < Width; i++)
{
for (int j = 0; j < Height; j++)
{
bitmap.SetPixel(i, j, InputImg.Colortable[GaussianStretch(r[i + j * Width], InputImg.CumulativeProbability[0], BandMin, InputImg.Mean[0], InputImg.Stddev[0])]);
}
}
break;
}
case StretchModes.SquareRoot:
{
//平方根
for (int i = 0; i < Width; i++)
{
for (int j = 0; j < Height; j++)
{
bitmap.SetPixel(i, j, InputImg.Colortable[SquarerootStretch(r[i + j * Width], InputImg.StretchInfo[0].Item1, InputImg.StretchInfo[0].Item2)]);
}
}
break;
}
case StretchModes.Logarithmic:
{
//对数
for (int i = 0; i < Width; i++)
{
for (int j = 0; j < Height; j++)
{
bitmap.SetPixel(i, j, InputImg.Colortable[LinearStretch(LogarithmicStretch(r[i + j * Width], InputImg.StretchInfo[0].Item1, InputImg.StretchInfo[0].Item2), InputImg.StretchInfo[0].Item1, InputImg.StretchInfo[0].Item2)]);
}
}
break;
}
default:
{
//不是0-9还能是啥？
throw new Exception("拉伸模式未知。");
}
}
}
#endregion
#region 彩色图
else //三波段组合
{
Band redBand = InputImg.GDALDataset.GetRasterBand(InputImg.BandList[0]);
Band greenBand = InputImg.GDALDataset.GetRasterBand(InputImg.BandList[1]);
Band blueBand = InputImg.GDALDataset.GetRasterBand(InputImg.BandList[2]);
double[] r = new double[Width * Height];
double[] g = new double[Width * Height];
double[] b = new double[Width * Height];
redBand.ReadRaster(0, 0, InputImg.Width, InputImg.Height, r, Width, Height, 0, 0);
greenBand.ReadRaster(0, 0, InputImg.Width, InputImg.Height, g, Width, Height, 0, 0);
blueBand.ReadRaster(0, 0, InputImg.Width, InputImg.Height, b, Width, Height, 0, 0);
//红、绿、蓝波段对应的波段索引。
int Red = InputImg.BandList[0] - 1;
int Green = InputImg.BandList[1] - 1;
int Blue = InputImg.BandList[2] - 1;
//红、绿、蓝波段的统计最小值（Item2）、最大值（Item3）。
double RedMin = InputImg.Min[Red];
double RedMax = InputImg.Max[Red];
double GreenMin = InputImg.Min[Green];
double GreenMax = InputImg.Max[Green];
double BlueMin = InputImg.Min[Blue];
double BlueMax = InputImg.Max[Blue];
switch (StretchMode)
{
case StretchModes.No_stretch:
{
//无拉伸
BitmapData bitmapData = bitmap.LockBits(new Rectangle(0, 0, Width, Height), ImageLockMode.ReadWrite, PixelFormat.Format32bppRgb);
try
{
int stride = bitmapData.Stride;
IntPtr buf = bitmapData.Scan0;
blueBand.ReadRaster(0, 0, InputImg.Width, InputImg.Height, buf, Width, Height, DataType.GDT_Byte, 4, stride);
greenBand.ReadRaster(0, 0, InputImg.Width, InputImg.Height, new IntPtr(buf.ToInt32() + 1), Width, Height, DataType.GDT_Byte, 4, stride);
redBand.ReadRaster(0, 0, InputImg.Width, InputImg.Height, new IntPtr(buf.ToInt32() + 2), Width, Height, DataType.GDT_Byte, 4, stride);
}
finally
{
bitmap.UnlockBits(bitmapData);
}
break;
}
case StretchModes.Linear:
case StretchModes.Linear_1:
case StretchModes.Linear_2:
case StretchModes.Linear_5:
case StretchModes.CustomLinear:
{
//线性
for (int i = 0; i < Width; i++)
{
for (int j = 0; j < Height; j++)
{
Color newColor = Color.FromArgb(
LinearStretch(r[i + j * Width], InputImg.StretchInfo[Red].Item1, InputImg.StretchInfo[Red].Item2),
LinearStretch(g[i + j * Width], InputImg.StretchInfo[Green].Item1, InputImg.StretchInfo[Green].Item2),
LinearStretch(b[i + j * Width], InputImg.StretchInfo[Blue].Item1, InputImg.StretchInfo[Blue].Item2));
bitmap.SetPixel(i, j, newColor);
}
}
break;
}
case StretchModes.Equalization:
{
//直方图均衡
for (int i = 0; i < Width; i++)
{
for (int j = 0; j < Height; j++)
{
Color newColor = Color.FromArgb(
EqualizationStretch(r[i + j * Width], InputImg.CumulativeProbability[Red], RedMin, RedMax),
EqualizationStretch(g[i + j * Width], InputImg.CumulativeProbability[Green], GreenMin, GreenMax),
EqualizationStretch(b[i + j * Width], InputImg.CumulativeProbability[Blue], BlueMin, BlueMax));
bitmap.SetPixel(i, j, newColor);
}
}
break;
}
case StretchModes.Gaussion:
{
//高斯
for (int i = 0; i < Width; i++)
{
for (int j = 0; j < Height; j++)
{
Color newColor = Color.FromArgb(
GaussianStretch(r[i + j * Width], InputImg.CumulativeProbability[Red], RedMin, InputImg.Mean[Red], InputImg.Stddev[Red]),
GaussianStretch(g[i + j * Width], InputImg.CumulativeProbability[Green], GreenMin, InputImg.Mean[Green], InputImg.Stddev[Green]),
GaussianStretch(b[i + j * Width], InputImg.CumulativeProbability[Blue], BlueMin, InputImg.Mean[Blue], InputImg.Stddev[Blue]));
bitmap.SetPixel(i, j, newColor);
}
}
break;
}
case StretchModes.SquareRoot:
{
//平方根
for (int i = 0; i < Width; i++)
{
for (int j = 0; j < Height; j++)
{
Color newColor = Color.FromArgb(
SquarerootStretch(r[i + j * Width], RedMin, RedMax),
SquarerootStretch(g[i + j * Width], GreenMin, GreenMax),
SquarerootStretch(b[i + j * Width], BlueMin, BlueMax));
bitmap.SetPixel(i, j, newColor);
}
}
break;
}
case StretchModes.Logarithmic:
{
//对数
for (int i = 0; i < Width; i++)
{
for (int j = 0; j < Height; j++)
{
Color newColor = Color.FromArgb(
LinearStretch(LogarithmicStretch(r[i + j * Width], RedMin, RedMax), RedMin, RedMax),
LinearStretch(LogarithmicStretch(g[i + j * Width], GreenMin, GreenMax), GreenMin, GreenMax),
LinearStretch(LogarithmicStretch(b[i + j * Width], BlueMin, BlueMax), BlueMin, BlueMax));
bitmap.SetPixel(i, j, newColor);
}
}
break;
}
default:
{
//不是0-9还能是啥？
break;
}
}
}
#endregion
return(bitmap);
}
