环境：VS2010，C#，GDAL1.7
读取影像：
1 using System; 2 using System.Collections.Generic; 3 using System.ComponentModel; 4 using System.Data; 5 using System.Drawing; 6 using System.Linq; 7 using System.Text; 8 using System.Windows.Forms; 9 using System.Diagnostics; 10 using System.Drawing.Imaging; 11 using OSGeo.GDAL; 12 using AppScene; 13 14 namespace GdalReader 15 { 16 public partial class Form1 : Form 17 { 18 public Form1() 19 { 20 InitializeComponent(); 21 } 22 string __ImagePath = string.Empty; 23 private OSGeo.GDAL.Dataset __Geodataset; 24 private int[] __DisplayBands; 25 private Rectangle __DrawRect; 26 private Bitmap __BitMap; 27 private void btnBrower_Click(object sender, EventArgs e) 28 { 29 OpenFileDialog dlg = new OpenFileDialog(); 30 dlg.Title = ""; 31 dlg.Filter = "Img(*.img)|*.img"; 32 if (dlg.ShowDialog() == DialogResult.OK) 33 { 34 OSGeo.GDAL.Gdal.AllRegister(); 35 __ImagePath = dlg.FileName; 36 txtPath.Text = __ImagePath; 37 OSGeo.GDAL.Dataset dataset = OSGeo.GDAL.Gdal.Open(__ImagePath, OSGeo.GDAL.Access.GA_ReadOnly); 38 __Geodataset = dataset; 39 if (__Geodataset != null) 40 { 41 if (__Geodataset.RasterCount >= 3) 42 __DisplayBands = new int[3] { 1, 2, 3 }; 43 else 44 __DisplayBands = new int[3] { 1, 1, 1 }; 45 } 46 double[] dd = new double[4]; 47 dataset.GetGeoTransform(dd); 48 string prj = dataset.GetProjection(); 49 50 string str = string.Format("波段数目:{0}\n行数：{1};列数：{2}\n坐标参考：{3},{4},{5},{6}\n", __Geodataset.RasterCount, __Geodataset.RasterXSize, __Geodataset.RasterYSize, dd[0], dd[1], dd[2], dd[3]); 51 str += prj + "\n"; 52 for (int i = 1; i <= __Geodataset.RasterCount; ++i) 53 { 54 OSGeo.GDAL.Band band = dataset.GetRasterBand(i); 55 str += "波段" + i + "：" + band.DataType.ToString(); 56 57 } 58 richTextBox1.Text = str; 59 InitialIMG(); 60 SimpleRasterShow simRaster = new SimpleRasterShow(""); 61 simRaster.IsOn = true; 62 simRaster.bitmap = __BitMap; 63 sceneControl1.CurrentWorld.RenderableObjects.ChildObjects.Add(simRaster); 64 } 65 } 66 67 public void InitialIMG() 68 { 69 if (__Geodataset != null) 70 { 71 Rectangle rect = new Rectangle(0, 0, __Geodataset.RasterXSize, __Geodataset.RasterYSize); 72 float width = (float)this.Width; 73 float height = (float)this.Height; 74 RectangleF Extent = ExtRect(rect, width, height); 75 double scale = Extent.Width / this.Width; 76 //double scaley = Extent.Height / this.Height; 77 double bufWidth = __Geodataset.RasterXSize / scale; 78 double bufHeight = __Geodataset.RasterYSize / scale; 79 Debug.WriteLine("Buffered width is:" + bufWidth); 80 Debug.WriteLine("Buffered height is:" + bufHeight); 81 double bufX = (this.Width - bufWidth) / 2.0; 82 double bufY = (this.Height - bufHeight) / 2.0; 83 __DrawRect = new Rectangle((int)bufX, (int)bufY, (int)bufWidth, (int)bufHeight); 84 Rectangle ExtentRect = new Rectangle(0, 0, (int)bufWidth, (int)bufHeight); 85 //__DispRectCenter = new PointF((float)(bufX + bufWidth / 2.0), (float)(bufY + bufHeight / 2.0)); 86 // __Zoom = (float)scale; 87 //__Zoom=(float)(scalex>scaley?scalex:scaley); 88 __BitMap = RSImg2BitMap(__Geodataset, ExtentRect, __DisplayBands); 89 // Invalidate(); 90 } 91 } 92 public RectangleF ExtRect(Rectangle rect, float width, float height) 93 { 94 double midX = rect.X + rect.Width / 2.0; 95 double midY = rect.Y + rect.Height / 2.0; 96 double newh = 0.0; 97 double neww = 0.0; 98 //Adjust according to width, if 99 if (rect.Width * 1.0 / rect.Height > width / height)100 {101 newh = (height * 1.0 / width) * rect.Width;102 neww = rect.Width;103 //newh = (rect.Height*1.0 / rect.Width) * height;104 //neww = width;105 }106 else107 {108 //neww = (rect.Width*1.0 / rect.Height) * width;109 //newh = height;110 neww = (width * 1.0 / height) * rect.Width;111 newh = rect.Height;112 }113 RectangleF newRect = new RectangleF((float)(midX - neww / 2.0), (float)(midY - newh / 2.0), (float)neww, (float)newh);114 return newRect;115 }116 public Bitmap RSImg2BitMap(OSGeo.GDAL.Dataset dataset,117 Rectangle ExtentRect, int[] displayBands)118 {119 int x1width = ExtentRect.Width;120 int y1height = ExtentRect.Height;121 122 Bitmap image = new Bitmap(x1width, y1height,123 System.Drawing.Imaging.PixelFormat.Format24bppRgb);124 int iPixelSize = 3;125 126 if (dataset != null)127 {128 BitmapData bitmapdata = image.LockBits(new129 Rectangle(0, 0, x1width, y1height),130 ImageLockMode.ReadWrite, image.PixelFormat);131 int ch = 0;132 133 try134 {135 unsafe136 {137 for (int i = 1; i <= displayBands.Length; ++i)138 {139 OSGeo.GDAL.Band band = dataset.GetRasterBand(displayBands[i - 1]);140 int[] buffer = new int[x1width * y1height];141 band.ReadRaster(0, 0, __Geodataset.RasterXSize,142 __Geodataset.RasterYSize, buffer, x1width, y1height, 0, 0);143 int p_indx = 0;144 145 if ((int)band.GetRasterColorInterpretation() == 5)146 ch = 0;147 if ((int)band.GetRasterColorInterpretation() == 4)148 ch = 1;149 if ((int)band.GetRasterColorInterpretation() == 3)150 ch = 2;151 if ((int)band.GetRasterColorInterpretation() != 2)152 {153 double maxVal = 0.0;154 double minVal = 0.0;155 maxVal = GetMaxWithoutNoData(dataset,156 displayBands[i - 1], -9999.0);157 minVal = GetMinWithoutNoData(dataset,158 displayBands[i - 1], -9999.0);159 for (int y = 0; y < y1height; y++)160 {161 byte* row = (byte*)bitmapdata.Scan0 +162 (y * bitmapdata.Stride);163 for (int x = 0; x < x1width; x++, p_indx++)164 {165 byte tempVal = shift2Byte(buffer[p_indx], maxVal, minVal, -9999.0);166 row[x * iPixelSize + ch] = tempVal;167 }168 }169 }170 else171 {172 double maxVal = 0.0;173 double minVal = 0.0;174 maxVal = GetMaxWithoutNoData(dataset,175 displayBands[i - 1], -9999.0);176 minVal = GetMinWithoutNoData(dataset,177 displayBands[i - 1], -9999.0);178 for (int y = 0; y < y1height; y++)179 {180 byte* row = (byte*)bitmapdata.Scan0 +181 (y * bitmapdata.Stride);182 for (int x = 0; x < x1width; x++, p_indx++)183 {184 byte tempVal = shift2Byte 185 (buffer[p_indx], maxVal, minVal, -9999.0);186 row[x * iPixelSize] = tempVal;187 row[x * iPixelSize + 1] = tempVal;188 row[x * iPixelSize + 2] = tempVal;189 }190 }191 }192 ch++;193 }194 }195 }196 finally197 {198 image.UnlockBits(bitmapdata);199 }200 }201 return image;202 }203 #region RASTERoperations204 /// 205 /// Function of shift2Byte206 /// 207 /// this function will shift a value into a range of byte: 0~255 to be displayed in the graphics. 208 /// the type of the value 209 /// the value that will be converted to byte210 /// the maximum value range211 /// the minimum value range212 /// a value within the byte range 213 public byte shift2Byte (T val, double Maximum, double Minimum)214 {215 double a = 255 / (Maximum - Minimum);216 double b = 255 - (255 / (Maximum - Minimum)) * Maximum;217 double tempVal = Convert.ToDouble(val);218 byte value = Convert.ToByte(a * tempVal + b);219 return value;220 }221 /// 222 /// Function of shift2Byte223 /// 224 /// this function will shift a value into a range of byte: 0~255 to be displayed in the graphics. 225 /// the type of the value 226 /// the value that will be converted to byte227 /// the maximum value range228 /// the minimum value range229 /// the value for the non-sens pixel230 /// a value within the byte range 231 public byte shift2Byte (T val, double Maximum, double Minimum, double noData)232 {233 double a = 0.0;234 double b = 0.0;235 double tempVal = Convert.ToDouble(val);236 a = 254 / (Maximum - Minimum);237 b = 255 - (254 / (Maximum - Minimum)) * Maximum;238 if (Math.Abs(tempVal) > Math.Abs(noData))239 return 0;240 try241 {242 return Convert.ToByte(a * tempVal + b);243 }244 catch245 {246 return 0;247 }248 }249 /// 250 /// Function of GetMaxWithoutNoData251 /// 252 /// Get the maximum data of certain band without the nodata values. 253 /// the band that will be statistically checked.254 /// the maximum values. 255 public double GetMaxWithoutNoData(OSGeo.GDAL.Dataset ds, int bandNumb, double __NoData)256 {257 double max = 0.0;258 double tempMax = 0.0;259 int index = 0;260 Band tempBand = ds.GetRasterBand(bandNumb);261 tempBand.GetMaximum(out tempMax, out index);262 if (Math.Abs(tempMax) < Math.Abs(__NoData))263 max = tempMax;264 else265 {266 OSGeo.GDAL.Band band;267 band = ds.GetRasterBand(bandNumb);268 //the number of columns269 int xSize = ds.RasterXSize;270 //the number of rows271 int ySize = ds.RasterYSize;272 double[] bandData = new double[xSize * ySize];273 //Read the data into the bandData matrix.274 OSGeo.GDAL.CPLErr err = band.ReadRaster(0, 0, xSize, ySize, bandData, xSize, ySize, 0, 0);275 for (long i = 0; i < xSize * ySize; i++)276 {277 if (bandData[i] > max & (Math.Abs(bandData[i]) < Math.Abs(__NoData)))278 max = bandData[i];279 }280 }281 return max;282 }283 /// 284 /// Function of GetMinWithoutNoData285 /// 286 /// Get the maximum data of certain band without the nodata values. 287 /// the band that will be statistically checked288 /// the maximum values. 289 public double GetMinWithoutNoData(OSGeo.GDAL.Dataset ds, int bandNumb, double __NoData)290 {291 double min = Math.Abs(__NoData);292 double tempMin = 0.0;293 int index = 0;294 Band tempBand = ds.GetRasterBand(bandNumb);295 tempBand.GetMinimum(out tempMin, out index);296 if (Math.Abs(tempMin) < Math.Abs(__NoData))297 min = tempMin;298 else299 {300 OSGeo.GDAL.Band band;301 band = ds.GetRasterBand(bandNumb);302 //the number of columns303 int xSize = ds.RasterXSize;304 //the number of rows305 int ySize = ds.RasterYSize;306 double[] bandData = new double[xSize * ySize];307 //Read the data into the bandData matrix.308 OSGeo.GDAL.CPLErr err = band.ReadRaster(0, 0, xSize, ySize, bandData, xSize, ySize, 0, 0);309 for (long i = 0; i < xSize * ySize; i++)310 {311 if (bandData[i] < min & (Math.Abs(bandData[i]) < Math.Abs(__NoData)))312 min = bandData[i];313 }314 }315 return min;316 }317 /// 318 /// Funcion of GetDatasetType319 /// 320 /// the band where the data type will be defined.321 /// 0 is the byte, 1 is int, 2 is double, and 3 is unknown. 322 public byte GetDatasetType(OSGeo.GDAL.Band band)323 {324 switch (band.DataType)325 {326 case OSGeo.GDAL.DataType.GDT_Byte:327 return 0;328 case OSGeo.GDAL.DataType.GDT_CFloat32:329 case OSGeo.GDAL.DataType.GDT_CFloat64:330 case OSGeo.GDAL.DataType.GDT_Float32:331 case OSGeo.GDAL.DataType.GDT_Float64:332 return 2;333 case OSGeo.GDAL.DataType.GDT_TypeCount:334 case OSGeo.GDAL.DataType.GDT_Unknown:335 return 3;336 default:337 return 1;338 }339 }340 #endregion341 private SceneControl sceneControl1;342 private void Form1_Load(object sender, EventArgs e)343 {344 this.sceneControl1 = new AppScene.SceneControl();345 // 346 // sceneControl1347 // 348 this.SuspendLayout();349 this.sceneControl1.Dock = System.Windows.Forms.DockStyle.Fill;350 this.sceneControl1.Location = new System.Drawing.Point(0, 0);351 this.sceneControl1.Name = "sceneControl1";352 this.sceneControl1.Size = new System.Drawing.Size(669, 457);353 this.sceneControl1.TabIndex = 0;354 this.panel1.Controls.Add(this.sceneControl1);355 sceneControl1.Focus();356 Application.Idle += new EventHandler(sceneControl1.OnApplicationIdle);357 this.ResumeLayout(false);358 }359 }360 } 在AppScene中渲染对象：
1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Text; 5 using AppScene; 6 using Microsoft.DirectX.Direct3D; 7 using Microsoft.DirectX; 8 using System.Drawing; 9 using System.IO; 10 using System.Runtime.Serialization.Formatters.Binary; 11 using Utility; 12 13 namespace GdalReader 14 { 15 class SimpleRasterShow : WorldWind.Renderable.RenderableObject 16 { 17 private CustomVertex.PositionTextured[] vertices;// 定义顶点变量 18 private Texture texture;//定义贴图变量 19 private Material material;//定义材质变量 20 public Bitmap bitmap = null; 21 public SimpleRasterShow(string name) 22 : base(name) 23 { 24 25 } 26 public override void Initialize(DrawArgs drawArgs) 27 { 28 this.isInitialized = true; 29 LoadTexturesAndMaterials(drawArgs); 30 VertexDeclaration(); 31 } 32 33 public override void Update(DrawArgs drawArgs) 34 { 35 if (!isInitialized && isOn) 36 { 37 Initialize(drawArgs); 38 } 39 } 40 41 public override void Render(DrawArgs drawArgs) 42 { 43 if (!isInitialized || !isOn) 44 return; 45 46 VertexFormats format = drawArgs.Device.VertexFormat; 47 FillMode currentCull = drawArgs.Device.RenderState.FillMode; 48 int currentColorOp = drawArgs.Device.GetTextureStageStateInt32(0, TextureStageStates.ColorOperation); 49 int zBuffer = drawArgs.Device.GetRenderStateInt32(RenderStates.ZEnable); 50 try 51 { 52 drawArgs.Device.RenderState.FillMode = FillMode.Solid; 53 drawArgs.Device.RenderState.Lighting = false; 54 55 drawArgs.Device.RenderState.DiffuseMaterialSource = ColorSource.Color1; 56 drawArgs.Device.RenderState.AlphaBlendEnable = true; 57 drawArgs.Device.RenderState.AlphaTestEnable = true; 58 59 drawArgs.Device.RenderState.ReferenceAlpha = 20; 60 drawArgs.Device.RenderState.AlphaFunction = Compare.Greater; 61 62 drawArgs.Device.RenderState.SourceBlend = Blend.SourceAlpha; 63 drawArgs.Device.RenderState.DestinationBlend = Blend.BothInvSourceAlpha; 64 drawArgs.Device.RenderState.BlendOperation = BlendOperation.Add; 65 66 drawArgs.Device.SetTexture(0, texture);//设置贴图 67 drawArgs.Device.TextureState[0].ColorOperation = TextureOperation.Modulate; 68 drawArgs.Device.TextureState[0].ColorArgument1 = TextureArgument.TextureColor; 69 drawArgs.Device.TextureState[0].ColorArgument2 = TextureArgument.Current; 70 drawArgs.Device.TextureState[0].AlphaOperation = TextureOperation.SelectArg2; 71 drawArgs.Device.TextureState[0].AlphaArgument1 = TextureArgument.TextureColor; 72 //device.TextureState[0].AlphaArgument2 = TextureArgument.Diffuse; 73 74 drawArgs.Device.VertexFormat = CustomVertex.PositionTextured.Format; 75 drawArgs.Device.DrawUserPrimitives(PrimitiveType.TriangleList, 2, vertices); 76 } 77 catch (Exception ex) 78 { 79 Log.Write(ex); 80 } 81 finally 82 { 83 drawArgs.Device.VertexFormat = format; 84 drawArgs.Device.RenderState.FillMode = currentCull; 85 drawArgs.Device.SetTextureStageState(0, TextureStageStates.ColorOperation, currentColorOp); 86 drawArgs.Device.SetRenderState(RenderStates.ZEnable, zBuffer); 87 drawArgs.Device.Indices = null; 88 } 89 } 90 91 private void VertexDeclaration1()//定义顶点1 92 { 93 vertices = new CustomVertex.PositionTextured[3]; 94 vertices[0].Position = new Vector3(10f, 10f, 0f); 95 vertices[0].Tu = 1; 96 vertices[0].Tv = 0; 97 vertices[1].Position = new Vector3(-10f, -10f, 0f); 98 vertices[1].Tu = 0; 99 vertices[1].Tv = 1;100 vertices[2].Position = new Vector3(10f, -10f, 0f);101 vertices[2].Tu = 1;102 vertices[2].Tv = 1;103 }104 private void VertexDeclaration()//定义顶点 105 {106 vertices = new CustomVertex.PositionTextured[6];107 vertices[0].Position = new Vector3(10f, 10f, 0f);108 vertices[0].Tu = 1;109 vertices[0].Tv = 0;110 vertices[1].Position = new Vector3(-10f, -10f, 0f);111 vertices[1].Tu = 0;112 vertices[1].Tv = 1;113 vertices[2].Position = new Vector3(10f, -10f, 0f);114 vertices[2].Tu = 1;115 vertices[2].Tv = 1;116 vertices[3].Position = new Vector3(-10f, -10f, 0f);117 vertices[3].Tu = 0;118 vertices[3].Tv = 1;119 vertices[4].Position = new Vector3(10f, 10f, 0f);120 vertices[4].Tu = 1;121 vertices[4].Tv = 0;122 vertices[5].Position = new Vector3(-10f, 10f, 0f);123 vertices[5].Tu = 0;124 vertices[5].Tv = 0;125 126 }127 128 private void LoadTexturesAndMaterials(DrawArgs args)//导入贴图和材质 129 {130 material = new Material();131 material.Diffuse = Color.White;132 material.Specular = Color.LightGray;133 material.SpecularSharpness = 15.0F;134 args.Device.Material = material;135 //MemoryStream memory = new MemoryStream();136 //BinaryFormatter formatter = new BinaryFormatter();137 //formatter.Serialize(memory, bitmap);138 int bufferSize = bitmap.Height * bitmap.Width * 4;139 140 System.IO.MemoryStream memory = new System.IO.MemoryStream();141 142 bitmap.Save(memory, System.Drawing.Imaging.ImageFormat.Bmp);143 memory.Seek(0, SeekOrigin.Begin);144 texture = TextureLoader.FromStream(args.Device, memory);145 //if (File.Exists(@"d:\temp.jpg"))146 //{147 // File.Delete(@"d:\temp.jpg");148 //}149 //bitmap.Save(@"d:\temp.jpg");150 //texture = TextureLoader.FromFile(args.Device, @"d:\temp.jpg");151 }152 153 public override void Dispose()154 {155 }156 157 public override bool PerformSelectionAction(DrawArgs drawArgs)158 {159 return true;160 // throw new NotImplementedException();161 }162 }163 } 结果：
存在的问题：
其实就是读取影像的时候构建了一个BitMap，没有和金字塔结合，没有实现在放大缩小的时候动态加载金字塔数据。对于特别大的影像加载会失败！
其实初始加载的时候应该根据画布的大小，加载一个缩略的全局影像，放大过程中动态加载不同级别的金字塔影像！