1
vote
1answer
27 views

How to export a IDW raster while keeping the search radius data

I want to export my IDW rasters that I made in ArcGIS to QGIS, however when I export my raster, the values are there but are no longer displayed. They are stored within each cell and are not ...
0
votes
0answers
29 views
+50

How to translate .bil files in a batch mode with QGIS?

I have some .bil files that I would like to convert into ASCII Gridded XYZ format files. It seems to work well with the Raster>Translate tool of QGIS when I process one file at a time. But I would ...
0
votes
0answers
22 views

How to open a raw binary raster in QGIS or R

I have a raw binary raster without a file ending, and no header file. I would like to open this in either QGIS or R and then convert to geotiff, but opening it seems to be a challenge. Here is a ...
0
votes
0answers
20 views

Is it possible to apply affine transformation (translation) to raster image?

Is it possible to move/translate a raster image in QGIS 2.2 (without using georeferencer) just like it can be done with a shapefile ? If not, alternatively can this be done with ArcGis?
1
vote
2answers
15 views

Create a common scale for different raster layers in GRASS, SAGA or QGIS

I have a number of layers that represent the temperature variability of the water in a lake. They have been generated trough interpolation and have different values as they represent temperatures ...
1
vote
2answers
52 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 ...
1
vote
1answer
18 views

How to set the output extents of rasterization in QGIS

I am trying to rasterize a bunch of vector based shape files in QGIS. All these files are covering certain types of ground use in a city (houses, street, open field,...). I need these files to be ...
0
votes
1answer
43 views

How to remove black box around georeferenced grayscale image in QGIS?

i'am trying to georeference a grayscale image (*.tif) in QGIS 2.2.0 Valmeria. It is working but QGIS draws a black box around the georeferenced raster image. If i use the option set 0 transparent, not ...
3
votes
1answer
38 views

Expand raster extent and set expanded values using nearest neighbor sampling

I have run a hydrodynamic model which has given me a grid of surface elevations throughout a bay. I am trying to process the results in ArcMap (or QGIS if needed). My goal is to take the current grid ...
0
votes
0answers
27 views

How to set raster values to NULL?

how can I define values to null? I tried it with the processing reclassify tool but I always get an error log (cannot open the result shape...or something like that).
0
votes
1answer
20 views

Clipping several raster layers to the same exact size QGIS

I'm new to QGIS, sorry if this is a newbie question... I need to clip about 40 different raster layers from one vector layer (that has the boundaries of 4 neighboring countries) but I need them all to ...
1
vote
0answers
45 views

Automating the production of GPS-compatible map tiles from georeferenced raster maps

I have a set of TIFF maps that I want to load onto Garmin GPS 62s units. The maximum size for each tile on the GPS is 3Mb and less than 1 million pixels. I manually produced one tile, following this ...
2
votes
1answer
40 views

Why do layers appear in the wrong order in QGIS 2.2?

I have a problem with in which order my vector and raster layers appear in QGIS. I have raster that I want to be the background of my other layers (vector). I place the vector layers on top in the ...
0
votes
1answer
35 views

How to isolate certain raster values using raster calculator?

I have a one band grayscale image. It has values 0-63 within the band. I need to isolate some of those values. Is there a way to do this in the raster calculator? QGIS 2.2//Windows 7
1
vote
1answer
39 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: ...
1
vote
0answers
25 views

How to use the raster calculator in the processing modeler of QGIS

I am trying to create a easy way to do raster analysis by building a model for two way raster calculations. I have two raster layers that I want to combine into a single raster. For now I've done this ...
1
vote
1answer
44 views

How to deal with empty corners in raster when calculating fragmentation index

I have clipped buffer area around coordinate from one big raster (forest cover). Such created raster was loaded in R where PatchStat function (library SDMTools) gives fragmentation index. After ...
1
vote
2answers
31 views

Creating Many Uneven Buffers

Qgis 2.2, Windows 7 I am looking to create buffers around city lights (the raster). Currently, I have simple polygon buffers around the point layer (oecdminusa), but this is not accurately capturing ...
0
votes
0answers
31 views

Raster format similar to ECW

I need an alternative to the ECW format that we currently have for a new series of Ordnance Survey maps. The ECW format looks clearer and less pixelated than the new maps in Tif format (in QGIS). ...
1
vote
0answers
18 views

Calculating Percent Overlap Between Distribution Maps

Hello there, I am currently trying to calculate the percent overlap (basically the total amount of overlap where these two species come into contact) between Lithobates catesbeiana (first image) ...
1
vote
1answer
42 views

Why do the raster band values have different values than the raster statistics?

I am working on a raster file (1 Band). According to the raster metadata, my minimum value is 0 and maximum is 7458. This seems to be confirmed by the Style options that return some category values ...
3
votes
0answers
21 views

Continuous color band for a raster legend in QGIS composer legend

I'm looking for a way to insert continuous colour legend for a raster layer. I managed to create discrete symbols with values along the bar, but I would like to have a continuous bar with some values ...
0
votes
0answers
28 views

Extract raster values under under each polygon buffer in qgis

In qGIS: I have raster file and >100 points. I constructed buffers polygons (vector-->geoprocessing-->buffer) around each of the points. Than I clipped (raster-->extraction-->clipper) the raster file ...
1
vote
2answers
94 views

How to extract X Y coordinates and RGB from pixels using python in QGIS?

I'm trying to white a Python plugin in QGIS (2.2) to get, for each pixel of a raster image, its X Y coordinates, as well as, its RGB (3 bands) values. At first I opened the raster file using: rlayer ...
0
votes
0answers
24 views

How can I remove dipoles from rasterlayer in QGIS 2.2?

I work with geomagnetic survey data. When convertet into a rasterlayer, every object with a high magnetic potential (for exampel an iron-nail on the surface) is shown as very sharp anomalie called ...
2
votes
0answers
37 views

Zonal Statistics Freezing QGIS 2.2

Running on Windows; 8gb memory, 500gb HD, i5 cpu; Raster file: 250mb I am having a problem with zonal statistics advancing past 17%. I am trying to run statistics on a crop grown in certain counties. ...
0
votes
0answers
36 views

I had an error in Gdalwarp and i don't know the reason

I was trying to warp a raster using a mask and shift it before clipping but when i exectute the command bellow in Qgis/PyQt using QProcess: gdalwarp -s_srs "+proj=merc +a=6378137 +b=6356752 ...
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 ...
0
votes
0answers
16 views

Cell Statistics in QGIS

Cell Statistics in ArcGIS will calculate the mean (or statistic of choice) among multiple rasters on a cell-by-call basis. Can QGIS do this? If so, how?
2
votes
0answers
34 views

Does QGIS support .sld style files for raster layers?

I'm currently looking at the documentation for geoserver, and I'm trying to load a raster and .sld file in QGIS to see if I can edit .sld files for raster layers. The .sld and raster are located here: ...
2
votes
1answer
103 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
91 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 ...
0
votes
0answers
36 views

Turn vector layer in raster layer based on cost

Hy, I am trying to rasterize some vector layers into raster layers and I know this is possible with QGIS by using the rasterize function in the raster menu but I don't know how to do the following ...
1
vote
1answer
24 views

GEOTIFF Binary File with Color Display Issues

I have a GEOTIFF in QGIS that shows values of 0 and 1 and I want the 0 values to have no fill so that background vector layers can show through and so I can easily overlay things in a print composer ...
0
votes
0answers
32 views

I want to reproject data from 0-360 to -180 - 180 [duplicate]

I've been downloading data from NOAA in a CRS that goes from 0-360. The rest of my data is in -180 to 180. What's the easiest way to reproject or shift the data in QGIS? It took 30 seconds in ArcMap, ...
1
vote
1answer
48 views

QGIS combine Vectorlayer and Rasterlayer to one shapefile

I have to create some Thematic Maps, especially Choropleth Maps on Matlab. Therefore i've found a shapefile which I can use, but need to draw some lines there. I've imported my shapefile as a Vector ...
2
votes
0answers
89 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
46 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 ...
2
votes
1answer
31 views

How to properly combine and export (as raster) vector lines on top of raster

I have a georeferenced TIFF with building plans on it. I then laid topo lines on top of it. it looks right in QGis. I now want to export this as an image (i.e. with the topo lines overlaid). How do I ...
1
vote
0answers
26 views

Can I tell QGIS to load/show only a part of an image?

can I tell QGIS to load/show only a part of an image without to extract this region as an extra/ new image?
2
votes
1answer
43 views

Smooth out lines in QGIS

I have taken a raster image and coverted it to a vector file. It is an OS map which shows field boundaries etc. As the vector file has been created from the pixelated raster file the lines are ...
0
votes
0answers
28 views

IDW Interpolation Raster clipping

I used the CLIPPER tool under the 'Raster' menu to clip my interpolation raster with a polygon. the resulting output is not displaying anything even though the process completes without any errors. ...
0
votes
1answer
28 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 ...
1
vote
1answer
59 views

Calculation amount or number of certain pixel-values in a raster

It seems pretty simple but until now I could not find a proper solution: In a given raster i want to know the number or ratio of e.g. red pixels. Edit: to be more precise: I have a number a arial ...
0
votes
0answers
19 views

What information, Open Attribute table of stream segment shows?

I have delineated the watershed from DEM data. I have converted the stream segment(raster) to vector lines. In the attribute table of this vector lines, there are 3 columns, CAT, VALUE, LABEL, what ...
-1
votes
2answers
54 views

Polygon shapefile to Raster with Mask and Extent

I have a polygon shapefile (Vesijärvi lake). The lake has many islands, bays and inlets. When I look at the attribute table, there are actually two adjacent features: Northern lake and southern lake. ...
1
vote
1answer
36 views

How to perform a standard deviation stretch on a raster in QGIS

Is there a way to perform a (2) standard deviations stretch on a raster image in QGIS 2.2? I have found the raster styles menu, but the help says there is no help in my language (English) and whilst ...
1
vote
1answer
47 views

QGIS Quickly switching overlapping raster images

I'm new to QGIS, and haven't used arcGIS in about 5 years, however I've just seen someone using arcGIS and was able to quickly switch between overlapping rasters when checking registration. The top ...
0
votes
1answer
37 views

Merging Raster: ImportError: No module named _gdal_array

When I try to merge rasters I got following error message: _gdal_array = swig_import_helper() File "C:\PROGRA~1\QGISDU~1\apps\Python27\lib\site-packages\osgeo\gdal_array.py", line 18, in ...
1
vote
1answer
53 views

Floating point calculations in QGIS

How do I manage floating point calculations in QGIS? I have carried out 3 consecutive calculations on landsat bands. I end up with 32 bit floating point rasters on which I can't carry out a 4th ...