ossimAuxXmlSupportData Class Reference

Utility/support data class to extract the projection from a dot aux dot xml file commonly found with mrsid data. More...

#include <ossimAuxXmlSupportData.h>

Public Member Functions
	ossimAuxXmlSupportData ()
	default constructor More...
virtual	~ossimAuxXmlSupportData ()
	virtual destructor More...
ossimRefPtr< ossimProjection >	getProjection (const ossimFilename &file) const
	Method to get a projection if possible. More...

Private Member Functions
bool	getPath (const ossimString &path, const ossimXmlDocument &xdoc, ossimString &s) const
	Gets path from doc and initializes string. More...
bool	initializeProjection (const ossimXmlDocument xdoc, const std::string &wkt, ossimProjection *proj) const
	Sets tie and scale. More...
bool	getProjcsName (const std::string &wkt, std::string &name) const
	Get first parameter from PROJCS[ ... More...
ossimUnitType	getUnits (const std::string &wkt) const
	Gets units of Projected Coordinate System. More...

Detailed Description

Utility/support data class to extract the projection from a dot aux dot xml file commonly found with mrsid data.

Definition at line 34 of file ossimAuxXmlSupportData.h.

Constructor & Destructor Documentation

ossimAuxXmlSupportData()

ossimAuxXmlSupportData::ossimAuxXmlSupportData

(

)

default constructor

Definition at line 37 of file ossimAuxXmlSupportData.cpp.

{
}

~ossimAuxXmlSupportData()

ossimAuxXmlSupportData::~ossimAuxXmlSupportData ( )

virtual

virtual destructor

Definition at line 41 of file ossimAuxXmlSupportData.cpp.

{
}

Member Function Documentation

getPath()

bool ossimAuxXmlSupportData::getPath ( const ossimString &  path, const ossimXmlDocument &  xdoc, ossimString &  s  ) const

private

Gets path from doc and initializes string.

Parameters

path	Xml path to look for.
xdoc	Xml doc to look in.
s	String to initialize.

Returns

true on success and false if path is not found or if there are more than one of path.

Definition at line 234 of file ossimAuxXmlSupportData.cpp.

References ossimXmlDocument::findNodes().

Referenced by getProjection().

{
   bool result = false;

   std::vector<ossimRefPtr<ossimXmlNode> > xnodes;
   xdoc.findNodes(path, xnodes);
   if ( xnodes.size() == 1 ) // Error if more than one.
   {
      if ( xnodes[0].valid() )
      {
         s = xnodes[0]->getText();
         result = true;
      }
      else if(traceDebug())
      {
         ossimNotify(ossimNotifyLevel_WARN)
            << "ossimAuxXmlSupportData::getPath ERROR:\n"
            << "Node not found: " << path
            << std::endl;
      }
   }
   else if ( xnodes.size() == 0 )
   {
      if(traceDebug())
      {
         ossimNotify(ossimNotifyLevel_WARN)
            << "ossimAuxXmlSupportData::getPath ERROR:\n"
            << "Node not found: " << path
            << std::endl;
      }
   }
   else
   {
      if(traceDebug())
      {
         ossimNotify(ossimNotifyLevel_WARN)
            << "ossimAuxXmlSupportData::getPath ERROR:\n"
            << "Multiple nodes found: " << path
            << std::endl;
      }
   }

   if (!result)
   {
      s.clear();
   }
   return result;
   
} // bool ossimAuxXmlSupportData::getPath

getProjcsName()

bool ossimAuxXmlSupportData::getProjcsName ( const std::string &  wkt, std::string &  name  ) const

private

Get first parameter from PROJCS[ ...

] string.

Parameters

wkt	Well known tet string.
name	Initialized by this with name if found.

Returns

true on success, false on error.

Definition at line 287 of file ossimAuxXmlSupportData.cpp.

Referenced by getProjection().

{
   bool result = false;
   
   if ( wkt.size() )
   {
      // Find "PROJCS":
      std::string::size_type startPos = wkt.find( std::string("PROJCS[") );
      if ( startPos != std::string::npos )
      {
         startPos += 7; // Move to end of projcs[ string.
         
         // Find first comma ',':
         std::string::size_type endPos = wkt.find( ',', startPos+1 );
         if ( endPos != std::string::npos )
         {
            if ( startPos < endPos )
            {
               name = wkt.substr( startPos, endPos-startPos );
               if ( name.size() )
               {
                  result = true;
               }
            }
         }
      }
   }
   
   return result;
                  
} // End: ossimAuxXmlSupportData::getProgcsName

getProjection()

ossimRefPtr< ossimProjection > ossimAuxXmlSupportData::getProjection

(

const ossimFilename &

file

)

const

Method to get a projection if possible.

Parameters

file	File name to open.

Returns

Projection pointer wrapped in ref pointer. Can be null if projection cannot be established.

Definition at line 45 of file ossimAuxXmlSupportData.cpp.

References ossimString::contains(), ossimProjectionFactoryRegistry::createProjection(), ossimRefPtr< T >::get(), getPath(), getProjcsName(), ossimString::gsub(), initializeProjection(), ossimProjectionFactoryRegistry::instance(), ossim::StreamFactoryRegistry::instance(), ossimXmlDocument::read(), ossimString::size(), ossimString::string(), ossimString::substitute(), and ossimRefPtr< T >::valid().

Referenced by ossimMrSidReader::getExternalImageGeometry().

{
   ossimRefPtr<ossimProjection> result = 0;

   std::shared_ptr<ossim::istream> is = ossim::StreamFactoryRegistry::instance()->
      createIstream(file, std::ios_base::in | std::ios_base::binary);

   if ( is && is->good() )
   {
      // Read the xml document:
      ossimXmlDocument xdoc;
      if ( xdoc.read( *is ) )
      {
         // Get the WKT string
         ossimString wkt;
         ossimString path = "/PAMDataset/Metadata/GeodataXform/SpatialReference/WKT";
         if ( getPath( path, xdoc, wkt ) )
         {
            if ( wkt.size() )
            {
               // Substitute "&quot;":
               ossimString tmpWkt = wkt.substitute( ossimString("&quot;"), ossimString(""), true );
               
               ossimString name;
               if ( getProjcsName( tmpWkt.string(), name.string() ) )
               {
                  result = ossimProjectionFactoryRegistry::instance()->createProjection( name );
                  if ( result.valid() == false )
                  {
                     // Hack...
                     if ( name.contains("_NAD83_") )
                     {
                        cout << "name1: " << name << endl;
                        name.gsub( ossimString("Georef_NAD83_m"), ossimString("GeoRef_M"), false );
                        name.string() = std::string("NAD_1983_") + name.string();
                        cout << "name2: " << name << endl;
                        result = ossimProjectionFactoryRegistry::instance()->
                           createProjection( name );
                     }
                  }
                  
                  if ( result.valid() )
                  {
                     if ( initializeProjection( xdoc, tmpWkt.string(), result.get() ) == false )
                     {
                        // Zero out the result if tie or scale not set.
                        result = 0;
                     }
                  }
               }
            }
         }
      }  
   }
   
   return result;
   
} // End: ossimAuxXmlSupportData::getProjection

getUnits()

ossimUnitType ossimAuxXmlSupportData::getUnits ( const std::string &  wkt ) const

private

Gets units of Projected Coordinate System.

Parameters

wkt	Well known tet string.

Returns

Units.

Definition at line 320 of file ossimAuxXmlSupportData.cpp.

References ossimString::contains(), ossimString::downcase(), OSSIM_DEGREES, OSSIM_FEET, OSSIM_UNIT_UNKNOWN, and OSSIM_US_SURVEY_FEET.

Referenced by initializeProjection().

{
   ossimUnitType units = OSSIM_UNIT_UNKNOWN;
   if ( wkt.size() )
   {
      // Note this is order dependent, i.e. you have to look for "Foot_US" before "Foot".
      ossimString os = wkt;
      os.downcase();
      if ( os.contains("feet_intl") )
      {
         units = OSSIM_FEET;
      }
      else if ( os.contains("foot_us") )
      {
         units = OSSIM_US_SURVEY_FEET;
      }
      else if ( os.contains("feet") || os.contains("foot") )
      {
         units = OSSIM_FEET;
      }
      //---
      // There can be two "unit" blocks.  One for PROJCS and one for GEOGCS.
      // Do this last as the GEOGCS block will have Degree in it. May need to split
      // the two blocks and then search if this doesn't work.
      //---
      else if ( os.contains("degree") )
      {
         units = OSSIM_DEGREES;
      }
   }

   return units;
   
} // End: ossimAuxXmlSupportData::getUnits

initializeProjection()

bool ossimAuxXmlSupportData::initializeProjection ( const ossimXmlDocument  xdoc, const std::string &  wkt, ossimProjection *  proj  ) const

private

Sets tie and scale.

Parameters

xdoc	Xml document.
wkt	Well known tet string.

Returns

True on success, false on error.

Definition at line 104 of file ossimAuxXmlSupportData.cpp.

References ossimXmlDocument::findNodes(), getUnits(), ossimXmlAttribute::getValue(), ossimDpt::hasNans(), ossimMapProjection::isGeographic(), ossimDpt::makeNan(), MTRS_PER_FT, OSSIM_FEET, OSSIM_METERS, OSSIM_US_SURVEY_FEET, ossimNotify(), ossimNotifyLevel_WARN, ossimMapProjection::setDecimalDegreesPerPixel(), ossimMapProjection::setMetersPerPixel(), ossimMapProjection::setUlTiePoints(), ossimString::size(), size, ossimString::split(), ossimString::toFloat64(), US_METERS_PER_FT, ossimRefPtr< T >::valid(), ossimDpt::x, and ossimDpt::y.

Referenced by getProjection().

{
   bool result = false;

   ossimRefPtr<ossimMapProjection> mapProj = dynamic_cast<ossimMapProjection*>( proj );
   if ( mapProj.valid() )
   {
      // Find the tie and scale.
      ossimString path = "/PAMDataset/Metadata/MDI";
      std::vector<ossimRefPtr<ossimXmlNode> > xnodes;
      xdoc.findNodes(path, xnodes);
      if ( xnodes.size() )
      {
         ossimDpt tie;
         ossimDpt scale;
         tie.makeNan();
         scale.makeNan();
         
         for ( ossim_uint32 i = 0; i < xnodes.size(); ++i )
         {
            if ( xnodes[i].valid() )
            {
               ossimString value;
               ossimString attrName = "key";
               
               ossimRefPtr<ossimXmlAttribute> attr = xnodes[i]->findAttribute( attrName );
               if ( attr.valid() )
               {
                  if (attr->getValue() == "IMAGE__XY_ORIGIN" )
                  {
                     value = xnodes[i]->getText();
                     if ( value.size() )
                     {
                        // Split it:
                        std::vector<ossimString> list;
                        value.split( list, ossimString(","), true );
                        if ( list.size() == 2 )
                        {
                           if ( list[0].size() )
                           {
                              tie.x = list[0].toFloat64();
                           }
                           if ( list[1].size() )
                           {
                              tie.y = list[1].toFloat64();
                           }
                        }
                     }
                  }
                  else if (attr->getValue() == "IMAGE__X_RESOLUTION" )
                  {
                     value = xnodes[i]->getText();
                     if ( value.size() )
                     {
                        scale.x = value.toFloat64();
                     }
                  }
                  else if (attr->getValue() == "IMAGE__Y_RESOLUTION" )
                  {
                     value = xnodes[i]->getText();
                     if ( value.size() )
                     {
                        scale.y = value.toFloat64();
                     }
                  }
               }
               
            } // Matches: if ( xnodes[i].valid() )
            
         } // Matches: for ( ossim_uint32 i = 0; i < xnodes.size(); ++i )

         if ( !tie.hasNans() && !scale.hasNans() )
         {
            if ( mapProj->isGeographic() )
            {
               // Assuming tie and scale in decimal degrees:
               mapProj->setDecimalDegreesPerPixel( scale );
               ossimGpt gpt(tie.y, tie.x, 0.0);
               mapProj->setUlTiePoints( ossimGpt( gpt ) );
               result = true;
            }
            else
            {
               // Get the units:
               ossimUnitType units = getUnits( wkt );

               // Convert to meters:
               result = true;
               if ( units != OSSIM_METERS )
               {
                  if ( units == OSSIM_FEET )
                  {
                     tie.x = tie.x * MTRS_PER_FT;
                     tie.y = tie.y * MTRS_PER_FT;
                     scale.x = scale.x * MTRS_PER_FT;
                     scale.y = scale.y * MTRS_PER_FT;                     
                  }
                  else if ( units == OSSIM_US_SURVEY_FEET)
                  {
                     tie.x = tie.x * US_METERS_PER_FT;
                     tie.y = tie.y * US_METERS_PER_FT;
                     scale.x = scale.x * OSSIM_US_SURVEY_FEET;
                     scale.y = scale.y * OSSIM_US_SURVEY_FEET;
                  }
                  else
                  {
                     ossimNotify(ossimNotifyLevel_WARN)
                        << "ossimAuxXmlSupportData::initializeProjection WARNING: "
                        << "Unhandled unit type: " << units << std::endl;
                     result = false;
                  }
               }

               if ( result )
               {
                  mapProj->setMetersPerPixel( scale );
                  mapProj->setUlTiePoints( tie );
               }
            }
         }
         
      } // Matches: if ( xnodes.size() ) 
   }

   return result;
   
} // ossimAuxXmlSupportData::initializeProjection

---

The documentation for this class was generated from the following files:

• ossimAuxXmlSupportData.h
• ossimAuxXmlSupportData.cpp