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

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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 ...
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3answers
3k views

QGIS - extract raster values greater than 0

How can I extract values > 0 from an overall raster? I have a water level grid and a DTM from which I've derived flood depths (using the raster calculator) but obviously the final result contains ...
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208 views

How to get projection data (.prj) of raster image using GDAL/OGR?

I start with a boundary shape-file (think U.S. states) in lat/long that I convert to some projection, and then rasterize the result as a .tif. What I need now are the raster coordinates of the ...
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2answers
1k views

How to round up/down an pixel value of a raster to a pixel value with 2 decimal places?

I have a raster (DTM) with floating points as pixel value. Now i want to round up/down the pixel values (to its next nearest value) to 2 decimal places. I use ArcGIS (with extensions) and tried the ...
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9 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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118 views

Creating new raster based on spatial extent and classes of one raster and average of another using ArcMap?

I have a raster that is split into classes and I wanted to make a new raster with this raster's spatial extent and classes but displaying the average values from a different raster. I am not really ...
2
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1answer
37 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 ...
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1answer
24 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 ...
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1answer
68 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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77 views

mask raster with shapefile using gdalwarp/gdal

I am struggling to use gdalwarp with cutline option. The following command keeps failing and I do not understand why : gdalwarp -cutline shapefile.shp file.tiff newfile.tiff Warning 1: Self-...
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2answers
193 views

Creating a raster file from a shapefile using GeoTools with different colours for different features

The shapefiles that I am processing display information on an operation of a piece of equipment over an area, where the information is stored in steps as polygon features with various attributes and ...
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0answers
48 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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2answers
3k views

Count number of unique raster pixels in polygon using ArcMap?

I have a polygon shapefile and I want to generate a table of a count for each pixel value in each polygon. My main goal is to find out what pixel is most abundant in each polygon. I am using ArcMap ...
3
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1answer
33 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
17 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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17 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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1answer
441 views

Convert Raster to Numpy Array with only Arcpy and Numpy

All the articles I'm finding including GDAL or PIL(?) which I cannot use. So I am trying to convert a raster I have to a Numpy Array with Arcpy and Numpy and then calculate some statistics on it but ...
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1answer
291 views

Calculate tree cover over certain area from raster data

Last year Hansen et al. published Global Forest Change map as set of raster data available in TIFF format. Basically those are 30-meters resolution satellite images with pixel values ranging from 0 (...
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0answers
47 views

Why is mosaic dataset such large file? [on hold]

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 ...
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1answer
34 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 ...
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1answer
30 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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2answers
92 views

Webmapping option that allows rasters?

I'm trying to create an introductory GIS course that will involve an ideally simple web mapping component. I was underwhelmed that ArcGIS online doesn't support rasters, and surprised that MangoMap ...
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1answer
24 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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31 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 ...
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2answers
26 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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2answers
126 views

Removing parts of raster layer with QGIS (equivalent of vector difference tool)?

I'm trying to get the difference between two raster layers the same way we can do it with the difference tool with vector layers. I'm using QGIS 2.14. Anyone has already done that and can tell me how ...
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1answer
40 views

Is there a standard color palettes for the spectral indices?

Is there a standard color palette (or most commonly used in publications and other materials) for the spectral indices?
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1answer
48 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 ...
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1answer
213 views

Attribute table is missing in raster after using extract by mask tool

Every time I use the extract by mask tool, the rasters that are created don't have an attribute table (i.e it's greyed out). Does anyone know what is causing this and why these rasters essentially no ...
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29 views

Iterating columns and feature to raster conversion?

I cannot do iterations on fields correctly. The fields contain rain intensities. Each field represents a time ... 15 minutes, 30 min, 45 min .... I have 50 fields. I want to end with 50 raster ...
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1answer
72 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 ...
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29 views

How to remove the Na values from a stack of rasters?

In R I have a stack (nsw.stack) which contains 6 variables. I have clipped the extent. However, When I look at the summary it appears that there is a lot of NA values (see below). I think this is ...
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1answer
35 views

How to reassign Raster values to new values in QGIS?

For example, if the Raster has integer values ranging from -1 to 3 and the value that I am only interested in is 3, I then want to assign values -1 to 2 to 0 and then have the 3 value set to the value ...
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0answers
43 views

NumPy to GeoTiff for use with Gdal

I have a few NumPy arrays: lat, lon, and 6 data bands. I'd like to convert these to GeoTiff and then apply the gdalwarp function, based on a specific projection, to each band. Is there a standard way ...
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2answers
189 views

add multiple rasters, each located a branch too deep in separate folders - ArcGIS

I have a year of daily raster datasets (365) that I would like to use the Cell Statistics tool on; however, each raster is located in a separate folder so I cannot add all of them at once. ie: -...
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2answers
130 views

How to update raster pixel values based on another raster with conditions in QGIS?

I have 2 land cover rasters. I want to update parts of the first raster with values from the second using QGIS. The workflow should be like this: 1. Select values equal to 30 and 34 in the first ...
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2answers
34 views

How to convert a raster output in a stack in R into ArcGIS

I am modelling the response of a bird (skylark) to various climatic and topographical variables in the program R. Using the predict function I predicted the abundance per pixel (see below for code). I ...
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25 views

QGIS Lost precision when converting raster to vector

I am after running ordinary kriging, converting raster to vector I lose decimal value and only get whole number. I have added first the raster then the vector image.
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1answer
24 views

Updating a raster using a shapefile [closed]

I have a huge raster file and want to increment all the values within a relatively small shapefile by 1 in Python. Speed is of critical importance, as I have to do this many times. I have been ...
0
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1answer
72 views

GRASS 7 Cost surface and elevation points development

I'm a new to GIS and I'm trying to develop an optimal path across an area by using GRASS 7 features. It is very similar to the task given here. The problem is that I don't have any data with ...
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1answer
30 views

Iterating over a raster layer in ArcGIS using Python

I have a raster layer for drive times. I have another raster layer with my bounding geography. I want to tell ArcGIS: For every cell in geography: if the corresponding cell in drive time is not ...
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2answers
44 views

Calculating area of polygon within square mile in ArcGIS?

I would like to create a raster, where in every cell it returns the area of land in a polygon feature. So for example, every cell in the raster would give park land per square mile, or vacant land ...
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0answers
40 views

Multiple HDF5 files in single GDAL virtual raster

Does anyone know how to generate a single GDAL virtual raster linking multiple HDF5 files to each other? Each file represents different swaths of the globe with different lat/lon coordinates and data ...
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2answers
348 views

Extracting multiple values of raster to polygons using ArcGIS for Desktop?

I was hoping I could get some help on how to extract information from a land use raster using polygons. I have a layer with 157 polygons and a land use raster with multiple land use categories for the ...
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2answers
71 views

Create a raster with ranges from another raster

I have a raster that contains values ranging from 1-180. I am looking for a way to create a new raster where if the values of a cell in the original raster is between 1-10 the new raster cell gets the ...
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5answers
284 views

List of GDAL raster file extensions

I am trying to compile a list of file extensions that are accepted by GDAL, something like ['.tif', '.png', '.jpg', '.jpeg', ...] I found a list of GDAL Raster file formats, but the values in the "...
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22 views

Arc Viewshed2 requires a vertical coordinate system

When I use the Viewshed2 tool with Arc 10.4, a 010451 error results when I try to add the input raster layer to the tool. The error states that the input raster is missing a vertical coordinate ...
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1answer
136 views

QGIS: How to change symbology of a continuous raster to discrete with unequal intervals?

I'm new in QGIS and currently trying to convert my ArcGIS-layers into QGIS. One of these layers is a slope gradient raster. I want to change the symbology so that a specific rang of gradients will ...
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2answers
43 views

TIF with TFW not opening and NO spatial reference

I will receive tif files with the associated tfw. I always thought that these would open correctly in Arc. When I check the spatial reference on the tif it states undefined. So I try to add it myself, ...
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1answer
40 views

Statistical properties of raster image

I want to calculate mean and standard deviation of a raster image. In QGIS zonal statistics, we can calculate it within a polygon or a vector. But I want to calculate for whole image. In Python I'm ...