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gdal读取图像数据,构建gdi+显示


将GDALOpen打开的文件用GDI+绘画出来

基于MFC单文档(XXXXView类的基类选择CScrollView)

CTestView.h
{
	#include "gdal_priv.h"
	...
	GDALDataset* m_pDataset;
	CSize sizeTotal;	//设置滚动条
	CString picturePath;	//图片的位置
	
	BOOL test;		//文件是否打开
	ULONG_PTR m_gdiplusToken;
	..
}

TestView.cpp中

#include <gdiplus.h>

CTestView::TestView()
{
	// TODO: 在此处添加构造代码

	test=FALSE;
	//...
}

CTestView::~CTestView()
{
	// 释放GDI+资源  
	Gdiplus::GdiplusShutdown( m_gdiplusToken ); 
}
void CTestView::OnFileOpen()
{
	// TODO: 在此添加命令处理程序代码
	TCHAR szFilter[] = _T("TIF(*.tif)|*.tif|image file(*.bmp;*.jpg)|*.bmp;*.jpg|All Files(*.*)|*.*|");
	CFileDialog fileDlg(TRUE,NULL, NULL, 0, szFilter, this);
	fileDlg.m_ofn.lpstrTitle=_T("OPEN IMAGE");

	if (fileDlg.DoModal()==IDOK)
	{

			
		picturePath=fileDlg.GetPathName();
		
		GDALAllRegister();   
		std::string luj=CStringA(picturePath);
		m_pDataset =(GDALDataset*) GDALOpen(luj.c_str(),GA_ReadOnly );  
		
		if(m_pDataset==NULL )    
		{    
			AfxMessageBox(_T("文件打开失败!!!"));    
			return;    
		} 
		
		test=TRUE;
		
		Invalidate();
	}

}

void CTestView::OnDraw(CDC* pDC)
{
	TestDoc* pDoc = GetDocument();
	ASSERT_VALID(pDoc);
	if (!pDoc)
		return;

	// TODO: 在此处为本机数据添加绘制代码

	if(test)  
	{
		// 初始化GDI+  
		Gdiplus::GdiplusStartupInput gdiplusStartupInput;  
		Gdiplus::GdiplusStartup( &m_gdiplusToken, &gdiplusStartupInput, NULL );  

  		
		int dataWidth=m_pDataset->GetRasterXSize();  
		int dataHeight=m_pDataset->GetRasterYSize();  
		int dataBands =  m_pDataset->GetRasterCount(); 

		//设置滚动条
		sizeTotal.cx=m_pDataset->GetRasterXSize();
		sizeTotal.cy=m_pDataset->GetRasterYSize();
		SetScrollSizes(MM_TEXT,sizeTotal);

		
		BYTE* pBuffer = new BYTE[dataWidth*dataHeight*dataBands];   

		Gdiplus::Bitmap* m_pBitmap=NULL;
		
		if (dataBands==1)   //8位灰度图
		{
			int band_list[1]={1} ; 
			CPLErr err = m_pDataset->RasterIO(GF_Read, 0, 0, dataWidth, dataHeight, pBuffer, dataWidth, dataHeight,
												GDT_Byte,dataBands,NULL,1,dataWidth,1);
			m_pBitmap=::new Gdiplus::Bitmap(dataWidth, dataHeight,dataWidth*dataBands,           
				PixelFormat8bppIndexed, (BYTE*)pBuffer); 

			
			Gdiplus::ColorPalette *pal=(Gdiplus::ColorPalette *)malloc(sizeof(Gdiplus::ColorPalette)+256*sizeof(Gdiplus::ARGB));
			pal->Count=256;
			pal->Flags=0;
	
			for (int i=0;i<256;i++)
			{
				pal->Entries[i]=Gdiplus::Color::MakeARGB(255,i,i,i);
			}

			m_pBitmap->SetPalette(pal);
			free(pal);
		}
		else if(dataBands==3)  //24位RGB图
		{
			int band_list[3] = {3,2,1}; 
			CPLErr err = m_pDataset->RasterIO(GF_Read, 0, 0, dataWidth, dataHeight, pBuffer, dataWidth, dataHeight,
												GDT_Byte,dataBands,band_list,3,dataWidth*3, 1);  
			m_pBitmap=::new Gdiplus::Bitmap(dataWidth, dataHeight, dataWidth*dataBands,           
				PixelFormat24bppRGB, (BYTE*)pBuffer); 
		}
	   

	  
	Gdiplus::Graphics graphics(pDC->GetSafeHdc());  
	graphics.DrawImage(m_pBitmap, 0, 0,dataWidth,dataHeight);  

	delete pBuffer;
	ReleaseDC(pDC);  
	}  
	
}

参考:使用gdal读取图像数据,然后用构建gdi+位图显示

使用GDI+灰度化图像

使用GDI+进行图片处理时要注意的问题


转载自:https://blog.csdn.net/grllery/article/details/77898580