1
vote
0answers
17 views

Problem with polygon overlay in raster stats using gdal

I am using the raster_stats module in python to calculate the mean carbon value for different sets of polygons. Here is the code that I am using: africa_sat = ...
0
votes
2answers
63 views

using Python to calculate NDVI, output as a Geotiff

I need a script that can calculate NDVI from two separate input Geotiff files, then output the results as a Geotiff. I wrote following script, most of which is borrowed from various on-line sources ...
2
votes
1answer
52 views

Re-project raster image from Mercator to Equirectangular

I have a raster image of the world map in Mercator projection, square 1:1 format. I want transform the image into an Equirectangular projection accurately. I assumed from my research that GDAL would ...
0
votes
0answers
15 views

Make a raster with pixel scale 100 by 100 meter with gdal_rasterize

I'm asking here, because, I've got great results last time. Here it is the next of my adventure with gdal_rasterize, I want to make a raster picture where each pixel correspond to a square of 100 by ...
1
vote
2answers
54 views

Conversion of point grid to a raster with open source tools (Gdal, QGIS …)

I'm looking to do something which seem simple to me, but I haven't found a solution since 2 days I looked for. I've got a Postgis DB with lot of points (WGS84) spaced of 100 meters which cover a ...
0
votes
1answer
45 views

Gdal creating raster rotated wrong way

I have been trying to read in a stack of images for a timeseries and created an output raster that contains the max pixel values of the timeseries. The arrays were created using numpy img_stack = ...
1
vote
1answer
40 views

QGIS DEM (Terrain models) Mode Slope creates wrong data [duplicate]

I have a DEM raster file downloaded from the USGS site. The file can be downloaded here. I am trying to create a slope raster in percent with the DEM tool in QGIS. The GDAL command is the following: ...
4
votes
2answers
89 views

Converting shapefile to raster: Character attributes

I've got a shapefile that I would like to convert into a raster, but the trick is that the attribute I want a raster version of is character data. I'm familiar with geoprocessing using GDAL (in the ...
1
vote
3answers
106 views

Topography: How to get the x,y,z coordinates of highest or lowest point/pixel of a raster GIS?

Given a .tiff topographic raster image with mountains and deep sea, I am looking for the x,y,z specifics of the highest or lowest point. The x,y,z values being: altitude (z-coordinate) latitude ...
2
votes
2answers
68 views

Gdal: highest and lowest point/pixel, how to get their altitudes?

Given a .tiff topographic raster image. How to get the altitudes of the highest and lowest point/pixel ?
1
vote
2answers
52 views

Mask image based on no-data pixels in another image with different projection - GDAL or Python

I've got a land cover image which covers the whole globe, and a satellite image which covers a very small part of the globe. These two images have different projections, co-ordinate systems and pixel ...
1
vote
0answers
72 views

Workflow with raster in Qgis 2.2

I'm trying to build a workflow with the Qgis 2.2 processing toolbox. I want to clip a raster layer with a vector layer using the GDAL tool "clip with a layer mask". But it doesn't work. The error ...
2
votes
1answer
111 views

Georeferencing an image with GDAL, based on QGIS Georeferencer Plugin

I would like to georeference an image with GDAL. The image already has a spatial reference set (EPSG:31276). For the georeferencing, I have a list of 4 ground control points (also in EPSG:31276). ...
6
votes
1answer
92 views

GDAL equivalent of ArcGIS Mosaic

The word 'mosaic' is often used for quite different things within the worlds of ArcGIS and GDAL. With GDAL and it's downstream applications like Qgis it is common to see mosaic used in the context ...
2
votes
0answers
92 views

Per-pixel calculations on a raster stack using GDAL

In R, it's relatively trivial to perform per pixel calculations based on a raster stack (e.g., get std.dev for each pixel on a 12 layer GeoTIFF). Unfortunately, the speed is less than desirable when ...
0
votes
1answer
47 views

gdal's polygonize function (via qgis) is not turning monochrome rasters into readable shapefiles regardless of inversion of color scale

I've tried polygonizing this monochrome bitmap as this: and this: and either way it ends up looking like this when (zoomed in) after gdal's polygonize operation: Is there any way I can tell ...
3
votes
1answer
80 views

ArcGIS Raster Mosaic Dataset and GDAL VRT, when to use?

ArcGIS has a the Raster Mosaic Dataset, QGIS and friends have Virtual Raster Tables. A skim of the documentation reveals much similarity. They both create or enable an alternate representation of ...
0
votes
1answer
29 views

Cannot display Oracle raster images using QGis

I am dealing with QGIS 2.2 and the plug-in Oracle spatial georaster. Apparently the connection to the database can be made, as the raster images are listed once you press 'Connect', but when try to ...
0
votes
1answer
24 views

Convert a KML ImageOverlay to World Files with GDAL

I have many raster outputs from an Open Source radio transmission topographic path tool called SPLAT, georeferenced in KML image overlay format. I have figured out an easy way to use tools to ...
0
votes
1answer
67 views

Create Tiles for a raster(georeferenced) to use in leaflet

I have raster, with each pixel containing some data. What i want is to split a large image with each pixel's color is determined by its value, to show on leaflet layer.How to go about this ? raster ...
1
vote
0answers
36 views

Extra row and column in a raster after GDAL grid import

I'm exporting an ESRI grid to TIFF format and after that I'm reading this exported raster file into SAGA GIS. However when Saga reads this file in there appears to be an additional row and column in ...
3
votes
3answers
85 views

how to digitize areas of a raster and snap to the raster cells?

I need to digitize the extent of an ecw raster image where the RGB value is not black.(see attatchment)ie. not the envelope, just the area where the image is shown without the border areas. The black ...
1
vote
1answer
102 views

Clip raster layer with *raster* mask layer in QGIS

Given two input layers 1. The clip layer - an arbitrary layer (though in my case it's a float 1 band geotiff) 2. The mask layer - a paletted raster in which every pixel is either NO DATA or a single ...
0
votes
0answers
48 views

Update a NetCDF file using GDAL

I have to edit a NetCDF file using GDAL in C++ code. When I try to update a subset I have this error message: ERROR 6: The NETCDF driver does not support update access to existing datasets. How can ...
3
votes
2answers
89 views

Merge two rasters with no data value

I have two rasters: Raster A and B. Raster A has has only values of 0. The white area in Raster B are No Data values. I want to merge them to one raster (Raster C). So basically I want all pixels in ...
1
vote
0answers
48 views

Write raster with its attribute table and symbology

I am classifying lots of rasters and I'd like to automate the legend creation and symbology displaying for easy manipulation. Here is the kind of raster I'm dealing with: library(raster) r <- ...
0
votes
2answers
62 views

Is it possible to alter raster values without Arcpy? [closed]

I'd like to be able to alter raster values, through fairly simple equations, without using the module Arcpy. Is that possible? It seems like gdal, numpy, and rasterlang might make this possible but ...
0
votes
0answers
39 views

Choose what zoomlevel to read from for mbtiles file in GDAL

GDAL is supposed to read MBTiles files and to do so, it selects the highest zoomlevel available. However, is there a way to choose another zoomlevel? i.e. override the default and go for a lower one? ...
1
vote
1answer
147 views

Convert polygons in shape file to a numpy array?

I have a shape file containing a number of polygons and all attributes being text. I'm trying to import the polygons into numpy as an array where each polygon is represented as unique values. I ...
0
votes
1answer
64 views

How do I use wildcards to work around the GDAL character limit?

I am attempting to use the 'Merge' & 'Create VRT' tools in QGIS 2.0 on a folder with 3000+ raster tiles in. However whenever I try to perform this operation the following error appears: 'The ...
3
votes
1answer
82 views

White lines in merged GeoTIFF files after ImageMosaicing on GeoServer

I have merged 21 GeoTIFF images using GDAL utilities. Each image is the result of merging 500 smaller tiles. I am using ImageMosaic in Geoserver but I am getting a mosaic that contains white lines and ...
0
votes
0answers
84 views

gdal python set projection of a raster - does not work

Gdal 1.9.2, ECW driver: ECW/ERDAS Compressed Wavelets (SDK 3.x) I am having problems with the script that supposed to set projection of the ECW to EPSG:27700, i.e. the British_National_Grid. Please ...
1
vote
2answers
241 views

GDAL/proj4 equirectangular projection coordinate system units assumed by OGRSpatialReference and GDALDataset::GetGeoTransform()?

How do I configure my OGRSpatialReference object to specify an equirectangular projection system http://en.wikipedia.org/wiki/Equirectangular_projection where the affine geo-transform matrix (provided ...
1
vote
1answer
123 views

combine raster with another raster mask file - gdal

I have 2 rasters in GeoTiff format. One has all of the land and water and the other is a mask file that shows either 0 for water or 1 for land. I basically want my output to just have the land values ...
0
votes
0answers
60 views

Strange black pixel on edge when generating with gdaldem -hillshade

I'm getting a strange result when I'm generating an hillshade with the gdaldem hillshade command. Here is my command (see the compute_edges parameter): ...
1
vote
1answer
63 views

gdal_rasterize using a “string” as src_datasource

I would like to use a string as src_datasource for gdal_rasterize program. Is it possible to use something like a WKT definition to translate a single point to a raster? Somethink like ...
2
votes
2answers
158 views

How to export raster from PostGIS enabled DB as GTiff with gdal_translate

When I want to export a GTiff from my PostGIS DB with this code: gdal_translate -of GTiff PG":host='localhost' port:'5432' dbname='landslide' user='postgres' password='pass' schema='public' ...
2
votes
0answers
213 views

GDAL polygonize lines

I have a raster file containing roads (left image). I polygonize the raster file with GDAL (see the script below). In the end I like to have vector lines. However GDAL only gives me something like ...
1
vote
1answer
120 views

GDAL polygonize only certain raster values

I want to polygonize a raster file with GDAL. I only want to rasterize cells with a value of 0. Is it possible to specify that within the polygonize function or do I have to modify my raster before ...
4
votes
1answer
122 views

Generate hillshading with GDAL, and respect nodata

I'm still trying to nut out this problem of merging overlapping geotiffs. From the original dataset (here, a 20m resolution digital elevation model of the state of Victoria), I have reprojected it ...
1
vote
1answer
85 views

Load Raster Values into Shapefile [duplicate]

I have a shapefile containing many points. Some of these points fall within an area for which I have raster data. I would like to load the values of the raster which underlie each point into the ...
2
votes
1answer
137 views

How can I dynamically trim the informational border off of FAA sectional raster charts?

I'm trying to write a script that can automatically use GDAL to crop the informational border from the FAA's published sectional charts (GeoTIFF) found here: I know that I can use gdal_translate ...
1
vote
1answer
99 views

How to work with 16 GB orthophoto raster

I would like to use one GeoTIFF raster in a custom ArcGIS-Engine Application, but my provider gave me 4 orthophotos GeoTIFF 4 GB each, because GeoTIFF is limited to 4 GB. Is there any other way to ...
1
vote
0answers
80 views

GDAL and Python: How to “pad the extent” or otherwise handle band.ReadRaster() for area falling slightly outside the image bounds?

In a nutshell, I'm trying to create a bare-metal tiling utility using GDAL and Python. As you can see in the graphic below, which shows the perimeter of a raster and the OSM-structured tile index, ...
6
votes
2answers
473 views

Best way to clip a large raster ECW file ?

I am trying to clip a large ECW (details below) but the raster file is too big to be processed entirely. Some details of the ECW below Driver: ECW/ERDAS Compressed Wavelets (SDK 5.0) file size: ...
3
votes
5answers
237 views

Impossible to sum rasters because of nodata pixels

I have a set of rasters (.vrt) with daily soil moisture data. I want to sum the pixels of all rasters in order to have a measure by month. However, the whole world is not covered each day, which ...
4
votes
1answer
61 views

Raster Calculator Bug at start

I use ArcGIS 10.1 on a Windows XP. ArcGIS completely shuts down when I attempt to launch the "Raster Calculator" tool. Has this happened to someone else? Any ideas on how to solve this annoying issue? ...
1
vote
0answers
102 views

GDAL in Java fails on ReadRaster()

To summarize, trying to read a raster keeps giving me an UnsatisfiedLinkError that makes sense, but looking into the compiled GDAL jar, I don't know how to fix. gdal.AllRegister(); TheFile = ...
2
votes
0answers
106 views

How to convert a raster (array) to a NetworkX graph and do a * search?

I want to use a slope-raster for a a_star path analysis in NetworkX. I am using Python for this project. My test raster looks like this First I read in the raster with GDAL input_raster = ...
1
vote
0answers
106 views

How to add new raster store and publish for ECW fromat in GeoServer 2.4-RC2?

I am using GeoServer 2.4 RC2 and Tomcat7 on windows xp OS. I have extracted the gdal-data.zip (2.4.0) and geoserver-2.4-SNAPSHOT-gdal-plugin into Tomcat 7.0\webapps\geoserver\WEB-INF\lib. Now ...