[GIS] Does gdal_translate support multi thread

gdal-translate

I've seen that gdalwarp has the -multi option to use multiple threads. But I don't see that option for gdal_translate. Does gdal_translate support multi thread?

Best Answer

gdal_translate can not use Multithreading for computing. But it can use multithreaded compression for some formats e.g. for GeoTiff using -co NUM_THREADS=ALL_CPUS

NUM_THREADS=number_of_threads/ALL_CPUS: (From GDAL 2.1) Enable multi-threaded compression by specifying the number of worker threads. Worth for slow compressions such as DEFLATE or LZMA. Will be ignored for JPEG. Default is compression in the main thread.

Another Performance Tweak is to extend the I/O Buffer Cache Size using GDAL_CACHEMAX config option. The following sets the Cache size to 512MB:

--config GDAL_CACHEMAX 512

Related Solutions

gdal – How to Add Alpha Channel to MBTiles Using gdal_translate

For the issue "turned pngs", you may be able to use https://github.com/roblabs/gdal2tilesp

which has support for xyz, from the notes: Generates Leaflet layer for use with the XYZ default format. Where the tms parameter is set to false

I've also tried gdal2tiles.py and mb-util utilities. they made good mbtile from point of transparency but all the pngs are turned upside down see figure2 (gdalinfo shows that origin has wrong Y coordinate with "-")

python gdal2tilesp.py -h

-o OUTPUT_CACHE, --output=OUTPUT_CACHE
                    Format for output cache. Values allowed are tms and
                    xyz, being xyz the default value

QGIS – Guide to Using gdal_translate and -scale

Thanks for all of the suggestions and help. The scale normalization is very useful when doing code, however in my case the original idea of putting the minimum and maximum in code looks like the only solution at this point.

I did not find a solution for doing it at the command line.

Here is a code snippet from the working solution: (Note that originally I was writing nodata to 0 as well, and this method breaks the nodata transformation. In my code I had to re-run the translate with nodata set to 0 as the only transformation to get it to finish the whole task!)

from qgis.core import *
from qgis.utils import *
from qgis.gui import *

import processing
from PyQt4.QtCore import *


#define functions

def loadraster(cur_raster):
    fileInfo = QFileInfo(cur_raster)
    baseName = fileInfo.baseName()
    rlayer = QgsRasterLayer(cur_raster, baseName)
    if not rlayer.isValid():
      print "Layer failed to load!"
    return rlayer


proj = QgsProject.instance()
proj.clear()

infile = "C:/QGISwork/ving_script/mergetest.tif"
outfile = "C:/QGISwork/ving_script/mergetest_out.tif"

#load raster file
mlayer = loadraster(infile)
#this part gets the extent from the original file 

ext = mlayer.extent()
extrep = ','.join([unicode(ext.xMinimum()), unicode(ext.xMaximum()), unicode(ext.yMinimum()), unicode(ext.yMaximum())]) 

#now get the stats whcih contain min and max values
renderer = mlayer.renderer()
provider = mlayer.dataProvider()
extent = mlayer.extent()
stats = provider.bandStatistics(1, QgsRasterBandStats.All,extent, 0)

print stats.minimumValue
print stats.maximumValue

#we don't need the layer any more so clear memory
QgsMapLayerRegistry.instance().removeMapLayer(mlayer.id())

#Run the algorithm with all of the inputs:
processing.runalg('gdalogr:translate', infile, 100, True, "0", 0, "", extrep , False,  5, 4, 75, 6, 1, False, 3, False, "-scale "+str(stats.minimumValue)+" "+str(stats.maximumValue)+" "+"0 1", outfile)

Best Answer

Related Solutions

gdal – How to Add Alpha Channel to MBTiles Using gdal_translate

QGIS – Guide to Using gdal_translate and -scale

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