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conversion of (lidar-) hgt to bef

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Arndt Brenschede 2019-11-04 08:01:00 +01:00
parent 0c6b53d354
commit 5510eac7ec
1 changed files with 220 additions and 0 deletions
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brouter-map-creator/src/main/java/btools/mapcreator/ConvertLidarTile.java Normal file
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package btools.mapcreator;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;
public class ConvertLidarTile
{
public static int NROWS;
public static int NCOLS;
public static final short NODATA2 = -32767; // hgt-formats nodata
public static final short NODATA = Short.MIN_VALUE;
static short[] imagePixels;
private static void readHgtZip( String filename, int rowOffset, int colOffset ) throws Exception
{
ZipInputStream zis = new ZipInputStream( new BufferedInputStream( new FileInputStream( filename ) ) );
try
{
for ( ;; )
{
ZipEntry ze = zis.getNextEntry();
if ( ze.getName().endsWith( ".hgt" ) )
{
readHgtFromStream( zis, rowOffset, colOffset );
return;
}
}
}
finally
{
zis.close();
}
}
private static void readHgtFromStream( InputStream is, int rowOffset, int colOffset )
throws Exception
{
DataInputStream dis = new DataInputStream( new BufferedInputStream( is ) );
for ( int ir = 0; ir < 1201; ir++ )
{
int row = rowOffset + ir;
for ( int ic = 0; ic < 1201; ic++ )
{
int col = colOffset + ic;
int i1 = dis.read(); // msb first!
int i0 = dis.read();
if ( i0 == -1 || i1 == -1 )
throw new RuntimeException( "unexcepted end of file reading hgt entry!" );
short val = (short) ( ( i1 << 8 ) | i0 );
if ( val == NODATA2 )
{
val = NODATA;
}
setPixel( row, col, val );
}
}
}
private static void setPixel( int row, int col, short val )
{
if ( row >= 0 && row < NROWS && col >= 0 && col < NCOLS )
{
imagePixels[row * NCOLS + col] = val;
}
}
private static short getPixel( int row, int col )
{
if ( row >= 0 && row < NROWS && col >= 0 && col < NCOLS )
{
return imagePixels[row * NCOLS + col];
}
return NODATA;
}
public static void doConvert( String inputDir, int lonDegreeStart, int latDegreeStart, String outputFile ) throws Exception
{
int extraBorder = 0;
NROWS = 5 * 1200 + 1 + 2 * extraBorder;
NCOLS = 5 * 1200 + 1 + 2 * extraBorder;
imagePixels = new short[NROWS * NCOLS]; // 650 MB !
// prefill as NODATA
for ( int row = 0; row < NROWS; row++ )
{
for ( int col = 0; col < NCOLS; col++ )
{
imagePixels[row * NCOLS + col] = NODATA;
}
}
for ( int latIdx = -1; latIdx <= 5; latIdx++ )
{
int latDegree = latDegreeStart + latIdx;
int rowOffset = extraBorder + ( 4 - latIdx ) * 1200;
for ( int lonIdx = -1; lonIdx <= 5; lonIdx++ )
{
int lonDegree = lonDegreeStart + lonIdx;
int colOffset = extraBorder + lonIdx * 1200;
String filename = inputDir + "/" + formatLat( latDegree ) + formatLon( lonDegree ) + ".zip";
File f = new File( filename );
if ( f.exists() && f.length() > 0 )
{
System.out.println( "exist: " + filename );
readHgtZip( filename, rowOffset, colOffset );
}
else
{
System.out.println( "none : " + filename );
}
}
}
boolean halfCol5 = false; // no halfcol tiles in lidar data (?)
SrtmRaster raster = new SrtmRaster();
raster.nrows = NROWS;
raster.ncols = NCOLS;
raster.halfcol = halfCol5;
raster.noDataValue = NODATA;
raster.cellsize = 1 / 1200.;
raster.xllcorner = lonDegreeStart - ( 0.5 + extraBorder ) * raster.cellsize;
raster.yllcorner = latDegreeStart - ( 0.5 + extraBorder ) * raster.cellsize;
raster.eval_array = imagePixels;
// encode the raster
OutputStream os = new BufferedOutputStream( new FileOutputStream( outputFile ) );
new RasterCoder().encodeRaster( raster, os );
os.close();
// decode the raster
InputStream is = new BufferedInputStream( new FileInputStream( outputFile ) );
SrtmRaster raster2 = new RasterCoder().decodeRaster( is );
is.close();
short[] pix2 = raster2.eval_array;
if ( pix2.length != imagePixels.length )
throw new RuntimeException( "length mismatch!" );
// compare decoding result
for ( int row = 0; row < NROWS; row++ )
{
int colstep = halfCol5 ? 2 : 1;
for ( int col = 0; col < NCOLS; col += colstep )
{
int idx = row * NCOLS + col;
short p2 = pix2[idx];
if ( p2 != imagePixels[idx] )
{
throw new RuntimeException( "content mismatch: p2=" + p2 + " p1=" + imagePixels[idx] );
}
}
}
}
private static String formatLon( int lon )
{
if ( lon >= 180 )
lon -= 180; // TODO: w180 oder E180 ?
String s = "E";
if ( lon < 0 )
{
lon = -lon;
s = "E";
}
String n = "000" + lon;
return s + n.substring( n.length() - 3 );
}
private static String formatLat( int lat )
{
String s = "N";
if ( lat < 0 )
{
lat = -lat;
s = "S";
}
String n = "00" + lat;
return s + n.substring( n.length() - 2 );
}
public static void main( String[] args ) throws Exception
{
String filename90 = args[0];
String filename30 = filename90.substring( 0, filename90.length() - 3 ) + "bef";
int srtmLonIdx = Integer.parseInt( filename90.substring( 5, 7 ).toLowerCase() );
int srtmLatIdx = Integer.parseInt( filename90.substring( 8, 10 ).toLowerCase() );
int ilon_base = ( srtmLonIdx - 1 ) * 5 - 180;
int ilat_base = 150 - srtmLatIdx * 5 - 90;
doConvert( args[1], ilon_base, ilat_base, filename30 );
}
}