GDAL栅格矢量化

在这里主要提供直接能用的栅格矢量化代码，这个函数中路径输入为QStrng，如果是其他类型的，请直接转成const char *；

bool Polygonize(const QString& strImg, const QString& strShp)
{
    GDALDataset *poFlagDS = (GDALDataset *)GDALOpen(strImg.toUtf8().constData(),GA_ReadOnly);
    if (poFlagDS == NULL)
    {
        cout<<"can't open "+ strImg.toStdString();
        return false;
    }

    GDALDriver * poOgrDriver = OGRSFDriverRegistrar::GetRegistrar()->GetDriverByName("ESRI Shapefile");
    if (poOgrDriver == NULL)
    {
        cout<<"can't get driver";
        GDALClose(poFlagDS);
        return false;
    }

    QFileInfo info(strShp);
    if (info.exists())
        poOgrDriver->Delete(strShp.toUtf8().constData());

    GDALDataset* poDstDataset = poOgrDriver->Create(strShp.toUtf8().constData(),0,0,0,GDT_Unknown,NULL);
    if (poDstDataset == NULL)
    {
        GDALClose(poFlagDS);
        return false;
    }

    OGRSpatialReference* pSpecialReference = new OGRSpatialReference(poFlagDS->GetProjectionRef());
    const char* layerName = "polygon";
    OGRLayer* poLayer = poDstDataset->CreateLayer(layerName,pSpecialReference,wkbPolygon,0);
    if (poLayer == NULL)
    {
        cout<<"can't create layer";
        GDALClose(poFlagDS);
        GDALClose( poDstDataset );
        return false;
    }

    OGRFieldDefn ofDef_DN( LABELFIELD, OFTInteger );
    if ( (poLayer->CreateField(&ofDef_DN) != OGRERR_NONE) )
    {
        cout<<"can't create field";
        GDALClose(poFlagDS);
        GDALClose( poDstDataset );
        return false;
    }

    char** papszOptions = NULL;
    papszOptions = CSLSetNameValue(papszOptions,"8CONNECTED","8");
    GDALRasterBand *poFlagBand = poFlagDS->GetRasterBand(1);
    GDALRasterBand *poMaskBand = poFlagBand->GetMaskBand();
    CPLErr err = GDALPolygonize((GDALRasterBandH)poFlagBand,(GDALRasterBandH)poMaskBand,(OGRLayerH)poLayer,0,papszOptions,0,0);
    if (err != CE_None)
    { 
        cout<<"polygonize failed";
        GDALClose(poFlagDS);
        GDALClose( poDstDataset );
       
        return false;
    }
    GDALClose(poFlagDS);
    GDALClose(poDstDataset);
    return true;
}