sharpetronics/QGIS
1
0
Fork 0
mirror of https://github.com/qgis/QGIS.git synced 2025-04-19 00:04:52 -04:00
Code Issues Packages Projects Releases Wiki Activity

QgsRasterFileWriter::writeDataRaster(): do not set nodata on output when unneeded

Browse Source 
Currently if the source raster has no nodata value, the writer will still write
nan as the output nodata value, ignoring the flag that specifies if there is a
nodata value or not. On a raster with byte data type, this will cause
confusion on reading since the nodata value will be somehow cast as 0.

Make QgsRasterChecker check for nodata consistency between source and target, and
add a test file that shows the issue.
This commit is contained in:
Even Rouault 2016-05-28 10:52:36 +02:00
parent 3d95712009
commit e0d38ba3f9
3 changed files with 13 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
src/core/raster/qgsrasterchecker.cpp
View File

@ -95,8 +95,13 @@ bool QgsRasterChecker::runTest( const QString& theVerifiedKey, QString theVerifi
compare( "Source data type", verifiedProvider->srcDataType( band ), expectedProvider->srcDataType( band ), mReport, typesOk );
compare( "Data type", verifiedProvider->dataType( band ), expectedProvider->dataType( band ), mReport, typesOk );
// TODO: not yet sure if noDataValue() should exist at all
//compare( "No data (NULL) value", verifiedProvider->noDataValue( band ), expectedProvider->noDataValue( band ), mReport, typesOk );
// Check nodata
bool noDataOk = true;
compare( "No data (NULL) value existence flag", verifiedProvider->srcHasNoDataValue( band ), expectedProvider->srcHasNoDataValue( band ), mReport, noDataOk );
if ( verifiedProvider->srcHasNoDataValue( band ) && expectedProvider->srcHasNoDataValue( band ) )
{
compare( "No data (NULL) value", verifiedProvider->srcNoDataValue( band ), expectedProvider->srcNoDataValue( band ), mReport, noDataOk );
}
bool statsOk = true;
QgsRasterBandStats verifiedStats = verifiedProvider->bandStatistics( band );
@ -122,7 +127,7 @@ bool QgsRasterChecker::runTest( const QString& theVerifiedKey, QString theVerifi
mReport += "</table>";
mReport += "<br>";
if ( !statsOk || !typesOk )
if ( !statsOk || !typesOk || !noDataOk )
{
allOk = false;
// create values table anyway so that values are available

5
src/core/raster/qgsrasterfilewriter.cpp
View File

@ -342,7 +342,7 @@ QgsRasterFileWriter::WriterError QgsRasterFileWriter::writeDataRaster(
{
iter->startRasterRead( i, nCols, nRows, outputExtent );
blockList.push_back( nullptr );
if ( destProvider ) // no tiles
if ( destProvider && destHasNoDataValueList.value( i - 1 ) ) // no tiles
{
destProvider->setNoDataValue( i, destNoDataValueList.value( i - 1 ) );
}
@ -435,8 +435,11 @@ QgsRasterFileWriter::WriterError QgsRasterFileWriter::writeDataRaster(
{
//write data to output file. todo: loop over the data list
for ( int i = 1; i <= nBands; ++i )
{
if ( destHasNoDataValueList.value( i - 1 ) )
{
partDestProvider->setNoDataValue( i, destNoDataValueList.value( i - 1 ) );
}
partDestProvider->write( destBlockList[i - 1]->bits( 0 ), i, iterCols, iterRows, 0, 0 );
delete destBlockList[i - 1];
addToVRT( partFileName( fileIndex ), i, iterCols, iterRows, iterLeft, iterTop );

BIN
tests/testdata/raster/byte.tif vendored Normal file
View File

Binary file not shown.