Raster is a data format consisting of regular grids of values, usually stored in an image-like format.

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42 views

How to Serve a Cached/Mixed Raster to Geocortex

I have never used a Cached/Mixed Raster format before, but I had these air photos given to me and I have to get them served up to our Geocortex App. I've been trying for weeks to covert it to a JPEG ...
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27 views

Pixel based 10 year NDVI time series

I would to do pixel based 10 year NDVI time series analysis using MODIS data. I’ve 3 seasons in a year. Should I average all values in the study area per season?
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80 views

QGIS set default style for layers based on name

I know that it is possible to apply default fill/line/point and colour ramp styles for layers within a project, However... I have a model which spits out raster layers with defined names (e.g. ...
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20 views

Interpreting output from PCA tool of ArcGIS for Desktop?

I am looking for some assistance on interpreting the output from a PCA run in Arcmap. My data is comprised of 6 raster bands representing biophysical elements in the marine environment (SST, ...
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46 views

Resample raster to lower resolution

I am trying to resample a forest cover raster with high resolution (25 meters) and categorical data (1 to 13) to a new RasterLayer with a lower resolution (~ 1 km). My idea is to combine the forest ...
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8 views

How to do not display Nodata values on IMG raster

I have a problem when I try to visualise (in ArcGIS 10.1) a raster file on IMG (ERDAS IMAGINE) format. The NoData values are displayed in black and I cannot find a way to do not display them. I've ...
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38 views

Improving Clip Raster workflow in QGIS?

I've tried to come up with an open-source equivalent to the following process in ArcGIS 10.3: Spatial Analyst Toolbox > Extract by Mask target input: 1" SRTM DEM in EPSG 4019 mask layer: single ...
2
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1answer
35 views

How to doing spatial join for several rasters

I have four rasters, each of 32 bits (single band), with the same cell size, the same number of rows and columns and identical extension. I need to make something like a "Spatial join", I mean, I need ...
4
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68 views

How to selectively generate averaged raster layer from 5-year data raster layers in QGIS?

I would like to merge 5 years of world ocean surface productivity data raster into 1 averaged raster in QGIS. However, not every pixel has data in every year. To generate the raster layer with the ...
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28 views

Merging DEM file generted many negative value in QGIS

With four DEM files downloaded by Python Elevation package, I merged them in QGIS 2.8.3. I use raster-> Miscellanaous -> Input direction, no more attribute was added. The four dem data has ...
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50 views

How to calculate raster area or number of cells for multiple classes in a raster?

I have a raster with many classes and I want to know the area or the number of cells for each class. I found quite a few posts on this topic (see links below). None of the suggestions matched my ...
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1answer
36 views

Open MOD10A2 snow cover map in ArcGis [closed]

How to open classified MOD10A2 snow cover map in ArcGis? I tried as follows: ArcMap layer>>select Properties>>Symbology>>classified. It says I don't have a valid histogram.
2
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1answer
46 views

Calculating raster area by converting to points to account for latitude changes?

I am looking at a large geographic area (e.g., continental Africa). I generated a raster of modeled habitat (using MaxEnt) defined in WGS 1984 depicting the hypothetical distribution of an organism at ...
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0answers
31 views

ArcGIS how to geolocate/georeference raster data arrays?

How does one geolocate (or georeference) a raster of swath grided data with separate lat/lon arrays and multiple data bands using ArcMap 10.3? A sample data file (*.h5) can be downloaded from here ...
5
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1answer
74 views

Stratified Random Sampling Tool

Is there a way to produce a certain amount of random points over different classes in a raster in QGIS? I have extensions such as GRASS or GDAL, ...
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1answer
54 views

Extracting multiple raster data to point shapefile in ArcGIS ModelBuilder?

I used raster iterator tool in ArcGIS ModelBuilder read several raster files in IMG format and extract values of corresponding raster files to a point Shapefile using "Extract multiple values" tool in ...
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24 views

Convert a SHP file set to a categorised ASC raster with Qgis?

I have a shapefile with regolith (soil) data that I would like to use as a categorised raster (say 007_1ASC) in Maxent. The regolith data is in the following files: 007_1.cpg 007_1.dbf 007_1.prj ...
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2answers
42 views

Splitting, disaggregating, breaking up a merged raster file

I am using ArcMap 10.4.1 but I am also more than familiar with QGIS. I have a raster file (single band) from a merged grid on population statistics for Europe (please see image attached). The red ...
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23 views

Geoserver Dynamic Raster Masking Based on Request Parameter

Is it possible for Geoserver to dynamically mask out values above or below a certain threshold in a WMS or WCS Geo-tiff request? For instance I make a request with some threshold parameter like 49 ...
0
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1answer
52 views

Python Gdal write virtual raster

Is there a python module to create Virtual Raster (.vrt) xml files? Rather than writing text strings to a file, I'd like to know if there is an automated way to do this.
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1answer
35 views

How to create or reclassify a land cover raster based on distance to roads in ArcGIS 10.4?

I am using a raster of land cover (Globcover 2.2, 300 m resolution), which I managed to reclassify (in 2 land cover categories) and clip to my region of interest. I also have a shapefile of the roads ...
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14 views

Converting radiance raster values to luminance

I have two nightlight data layers of the same area, one is a VIIRS radiance raster (the raster values are radiance values in units of nanowatt/sq.cm/sr) and the other one is a point vector luminance ...
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1answer
38 views

GRASS/QGIS- “buffer” created with DEM analysis- how to avoid it?

I have, to start, a DEM raster and a shapefile, with random created points, within a given polygon. The DEM raster was clipped with that same polygon. With the DEM raster, I used GRASS to perform ...
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29 views

Raster to categories to shapefiles

I have a raster data file which is the population density. I would like to transfer this raster into a specific number of categories, let's say 5. After that I would like to convert the raster to a ...
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22 views

classify colourramp with new min and max value with python

For my script i want to update the existing colourramp of a raster with new min and max value. In my current code is can fill the min and max but can't classify and update the raster. How does the ...
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2answers
56 views

Can I extract circular buffers from polygon layers?

I have been working in QGIS with a large and detailed shapefile where remaining forest fragments are represented as polygons. I would like to extract circlular buffers, of various radii, from this ...
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1answer
59 views

How to delete one band from raster file?

I was working using drone imagery (regular camera) and there is this alpha band which is preventing me from doing maximum likelihood classification. I want to remove the alpha band. So far I used ...
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49 views

KML with raster in QGIS

I have a kml file which displays correctly in Google Earth but only as a bounding box in QGIS . What can I do to see the associated raster image?
2
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39 views

Comparing areas of two raster files

I need to compare the areas of two rasters for calculating the percentage parts from another. For example, I have one raster file which shows separated agriculture fields. The value of each field is 1 ...
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1answer
36 views

QGIS- extract raster information into a point return nulls

I have a 1) raster layer and a 2) point layer. I want to extract the pixel value to each point, but it is not working when using this tools (QGIS): plug-in "Point sampling tool" (the new shapefile ...
0
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1answer
27 views

How can I combine together cells within the same raster in ArcGIS 10.2?

I have a raster displaying Land Cover data for the UK at a cell size of 25m. The cells are currently categorised as one of 24 different types of land cover. Some of these are irrelevant to me, and ...
2
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1answer
25 views

How to extend an OSM or raster area in Qgis (into 'No Data' area)?

I need to do the opposite of clipping down a raster (or SHP file) in Qgis (or Gdal, Python etc - even R if someone can provide the script). I have a dataset from Open StreetMap (*.OSM) which includes ...
2
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1answer
65 views

Update raster color ramp with new min/max values using python?

For a script, I want to update the exsiting min and max of a colour ramp with a new one. In the image you can see what I want to update. To do so I tried to follow this thread. I tested the ...
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0answers
10 views

GRASS t.register (ERROR : maps= et file= sont mutuellement exclusifs) [maps and file = are mutually exclusive]

Je souhaite créer un strds. Pour cela j'ai créé un jeu de donnée à l'aide de t.create, puis j'utilise t.register pour ajouter deux cartes raster à mon jeu de données. Voici la commande que j'effectue :...
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1answer
26 views

I keep getting the same error when trying to clip a raster

Error: Cutline feature without a geometry. Consistently get the above error when trying to clip a raster. I have looked at all the other questions relating to this and tried all the 'fixes' however I ...
2
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1answer
43 views

Mapping raster values to nearest grid cell on a polyline

I'm not sure if the following task is possible in ArcGIS, or whether I need to use something like MatLab - I wondered whether the community could possibly advise if it is possible, and if so, what ...
2
votes
1answer
72 views

How to convert raster (big size) to points?

I have a raster : population density of Ivory Coast. I need to convert it to points, but I met several problems because of the size I think. Here is what I tried : 1) GRASS GIS 7 command : r.to....
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1answer
19 views

ST_AsRaster for polygon

Having a hard time to get a raster from a polygon ST_AsRaster(ST_Buffer(ST_GeomFromText('POLYGON((-30 40, -20 30, -25 20, -23 10, -30 40))', 4326), 50),ARRAY['8BUI'],ARRAY[118]); This line is ...
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52 views

How can I prevent gdal_translate from rounding coordinates when clipping?

I want to clip a raster (a VRT of several Ascii files) to a set of coordinates. Ideally I'd like to use gdal_translate to do this, but I only get an accurate result when using gdalwarp. gdal_translate ...
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19 views

ST_AsRaster ST_AsTiff

Can someone give me an example how to use AsRaster and ST_AsTiff together? I am having trouble to create a tiff image. SELECT ST_AsTiff(ST_AsRaster(ST_Buffer(ST_GeomFromText('POLYGON((-30 40, -20 30,...
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0answers
50 views

Why is mosaic dataset such large file? [closed]

I have been trying to export a number of scanned paper maps onto my database, and have been just adding them as raster layers as part of a larger group layer. I georeferenced them, and none of them ...
2
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1answer
48 views

Rasterize points in a map : result is not leasible. How to make the raster (points) bigger?

I have a vector layer (points) that I rasterized based on one attribute of the vector layer. I chose the GRASS GIS 7 command : v.to.rast.attribute. The raster layer appears in the map, but is not very ...
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1answer
42 views

Displaying raster images using Leaflet?

The purpose is to create a small web application using an open source product, preffered Leaflet (but I will Switch the product if it works within another Framework than leaflet), simply showing a ...
3
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1answer
34 views

Configuring Project CRS to reflect degree coordinates

seems like this is a common problem, but posts with similiar questions did not solve my problem. I have close to zero GIS background so apologies for my ignorance. My goal is to extract only a ...
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1answer
29 views

Using ModelBuilder to create smaller individual DEMs from a large DEM using multiple polygon?

How can I use a polygon (which is made up of smaller polygons) to create individual DEMs from a large DEM using the polygons as the mask/extent? I am trying to do this in ModelBuilder and it isn't ...
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2answers
39 views

Add raised features to digital terrain model in QGIS

I have a DTM onto which I need to 'stamp' a series of raised embankments. The DTM is a raster grid (in m above sea level) and the embankments are polylines containing the crest height (also in m.a....
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34 views

Error executing algorithm Clip raster by mask layer 'NoneType' object has no attribute 'GetGeoTransform'

Processing modeler: GDAL "clip raster by mask layer" tool I have a raster layer that I wish to be clipped by a polygon layer (buffer zone). I intend to repeat to process many times in a more ...
3
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2answers
224 views

Automatic selection of pixels, from a raster series, greater than minimum image of the series

Given a series of rasters, and the raster image of the minimum values of the series, I am looking for a python script capable of selecting, for each raster, the pixels whose values are greater than ...
2
votes
1answer
74 views

How can I select points within a part of a raster?

I have a map with huge amount of points (9562 villages) and two rasters: population density and land elevation. I am trying, without success for the moment, to select just those villages with high ...
1
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1answer
51 views

Determining height of raster class from DEM?

I have a raster layer with 2 already determined classes: Low vegetation and High vegetation. They don't mix, there is a characteristic border between them. It's a typical situation of altitudinal ...