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

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Polygonize only pixel values of 1 from a raster

I have a raster mask that I have created in QGIS (2.2.0) that consist of 0, 1 and nodata values. I would like to end up with a polygon dataset that consist of only the value of one pixels from this ...
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1answer
185 views

Projection mismatch when plotting precipitation with ggplot

I'm trying to plot accumulated precipitation in Brazil for a given period, see code below: Load packages library(raincpc) library(SDMTools) library(raster) library(ggplot2) library(rgdal) ...
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1answer
2k views

Exporting map to jpg (multiple times with python)?

I set symbology and exported each raster in my mxd (one by one) to jpg file. My script is ok and it works (it is shown at the bottom). The question is: how can I customly set my legend? Now I have ...
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47 views

Conservation International Hotspot Data

I am creating a Heat Map and need Conservation Internationals's Biodiversity Hotspot Data in GIS form. I have tried to find the data online, but have since been unable. Where would I be able to find ...
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1answer
565 views

Why the result of a merge of multiple raster is so big?

I try to merge 14 geotiff like this : Each geotiff is about 50Mb. I need a geotiff at the output My workflow : gdalbuildvrt -input_file_list list.txt test.vrt (where my list contains the name ...
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1answer
186 views

Processing MOD35_L2 HDF Cloud Masks

I am attempting to create a binary cloud mask from the MOD35_L2 data products located at http://ladsweb.nascom.nasa.gov/data/ When opening the MOD35_L2 data in ENVI or the MRTSwath tool it reports 6 ...
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114 views

How to reassign the values of a raster, based on the pixels of the raster beneath it?

In ArcMap 10.2.1, I have two rasters. Raster1 shows the extent of a habitat, and each pixel contains a categorical value for its land cover type (values 1-3). Raster1 has the smaller spatial extent of ...
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99 views

R: Can raster predict function pass to predict.rfsrc (a prediction function in a parallel verion of RandomForest)?

It seems that raster predict function can pass to predict.randomForest by setting the "type='response'". I am using a parallel version of randomForest package called the "randomForestSRC" and I am ...
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2answers
209 views

r.topidx error: required parameter output not set

I'm calling GRASS r.topidx from QGIS 2.2.0. I can get other tools to work on the DTM, for example r.watershed. But r.topidx I get the Oops message: Oooops! The following output layers could not be ...
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1answer
89 views

How I can sum 360 raster files in a folder with the Arcgis raster calculator?

In a folder I have 360 precipitation raster files and I want to sum them all to the raster calculator
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1answer
219 views

QGIS: Multiply Raster Value with Pixel size

i'm working on a map with population densities. My raster data contains values as [People/square meter] for each cell. I have per capita values of energy demand etc. which I want to multiply with the ...
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66 views

Choosing the map scale (1:nnn) for the given raster dimension

Starting points: let define the raster image size, say: 1800x900 pixels I want draw my own raster image map - by drawing polygons e.g. like "draw line from pixel with coordinates x100y100 to pixel ...
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1answer
130 views

Calculating Area of Raster Classes

I have a raster in a GRID format that was created by Image Classification. The GRID is projected in StatePlane meters, but I would like the area in square feet. I'm assuming I will need to use the ...
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83 views

R{raster} getValues(): error accessing values of large raster

I am getting the following, while extracting all values with: rs<-getValues(rster) Error in getRasterData(con, offset = offs, region.dim = reg, band = object at data@band): long vectors not ...
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54 views

Euclidean Distance Function performed on unprojected data

I am looking to perform a simple multi-criteria analysis on a data set comprised of two criterion: occurence of wildfires and road accessibility. First, the project CRS was enabled with "on the fly" ...
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1answer
225 views

Clip a shapefile based on raster extent with high accuracy

I am trying to clip a shapefile based on the extents of a smaller raster. I find the extent of the raster using this code: Extents = arcpy.sa.Raster(MyRaster).extent` Then, I use these lines to ...
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1answer
327 views

How do I overcome this problem of converting a raster layer to polygon form?

I am trying to convert a raster layer of U.S. climatic regions into polygon format using ArcMap 9.3 under Windows XP. The original data are to be found at the following address: Koppen Climate ...
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1answer
199 views

rasters as independent variables in logistic regression: must they have the same values classification?

I am planning to build a predictive model for land productivity using arcGIS 10.1. and logistic regression. In my model, the Independent Variables would be, among others, distance from rivers, ...
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2answers
159 views

Library to produce pretty print maps including rasters

I've come across a variety of libraries for easily producing maps for printing, in a fully reproducible way using some sort of code or configuration file. For example, Kartograph looks lovely, Vincent ...
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1answer
73 views

How to check the resolution of converted raster file

I have a raster file whose resolution I need to change to 0.5. I do this using this: g.region rast=my_raster res=0.5 After running this command, how do I verify whether the resolution has actually ...
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0answers
102 views

Overlaying Line (Vector) Layer on Raster Zones?

I will make my best attempt to clearly explain my problem. I am using ArcGIS 10 I have a raster layer with 3 values that make up zones. For the purpose of this example, lets say these zones are ...
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2answers
41 views

Adding Rasters as Columns in Shapefile using ArcGIS for Desktop? [closed]

I am currently working on a research project in a lab, and I am fairly familiar with ArcGIS (I'm only in high school and have done some previous work using ArcGIS). I was asked to add 3 columns onto a ...
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1answer
47 views

Why is the raster information No Data value set to -1.#IND?

I have a couple rasters that have been atmospherically corrected using the "landsat.toar" tool in Grass. When these rasters are output and I open up their properties in ArcCatalog, the NoData Value ...
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1answer
43 views

Symbolizing Raster using single Unique Value?

I'm dealing with a raster in GRID format. Currently it is symbolized in Unique Values and contains 5 classes. I'm trying to consolidate these to one class. Is there a way to do this and keep a single ...
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220 views

What's the correct way to reproject a population raster?

I'm working with a population raster that is in the WGS84 coordinate system, and I want to get it into a projected coordinate system (Albers Equal Area), using ArcGIS 10.1. According to the metadata, ...
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1answer
320 views

Raster and vector layer in the same CRS don't match

While adding multiple raster and vector layers (and setting them all in CRS WGS84) in QGIS 2.2, they don't seem to overlap. Interestingly enough, only raster files overlap between each other, the same ...
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1answer
96 views

Raster data with no values (ArcGIS)

Used a DEM raster and then used the extract-by-mask feature to shrink it to the shp file I'm working with. However, when I try to get unique values, it gives me the following error message: "The ...
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2answers
563 views

How to write raster field values into attribute table using ArcPy?

Is it possible to use ArcPy (10 or 10.1 )to write raster field types into a featureclass? either SDE or filegeodatabase?. I'm hoping to use arcpy as means of automating the process of adding rasters ...
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1answer
53 views

gdal_rasterize : getting area not in or touching polygon (options -at and -i)

I would like to capture the area that is not in a polygon (option -i) and that doesn't touch that polygon. gdal_rasterize -at will return the polygon + edges, but gdal_rasterize -at -i will not ...
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78 views

How to mask an vector field layer in MapServer?

given this layer def: LAYER NAME "waveswell_sigheight_grid" TYPE POINT CONNECTIONTYPE uvraster STATUS OFF #MASK "water_outline" #I get a "no data received" error in my browser ...
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492 views

How to change value of an individual pixel using arcpy?

I want to change the value of an individual pixel in a raster using arcpy. The code I wrote for changing the value is below, but it changes all of pixels in my raster. How can I set an individual ...
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1k views

In ArcMap 10.2, exporting raster as .tif with “use renderer” and “force RGB” still produces inaccurate colors

I have a DEM and my aim is to change its color ramp using ArcMap, then export this colored raster as a geotiff (8 bit). I checked "use renderer" and "force RGB" options but the results are not good ...
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1answer
45 views

Script never finishes and throws no errors. Creates lock on file until restart?

I have a simple script that gets all layers in a gdb and uses them to clip a DEM. What's happening though is it starts the clipping but never finishes and after killing the process I am unable to ...
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1answer
92 views

Adding shapefile elevation data to dted

I am a newbie to QGIS. Currently trying to augment a dted raster value file with vector shapefile(polygon) containing height of buildings. Have converted the shapefile into raster via rasterize ...
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1answer
35 views

Which format is more convenient to publish in Erdas Apollo?

I am from Bolivia and I need to publish some Satellite images in Erdas Apollo. My question is Which format is more convenient for publish in this software?, because I have Landsat5 TM images in TIFF ...
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2answers
4k views

Convert MapInfo raster file (.tab) to use it in QGIS and/or ArcGIS

I am trying to convert raster files from MapInfo (.ecw, .jpg, .TAB) in order to use them with QGIS or ArcGIS. I have access to all 3 softwares. I have tried Data interoperability tools in ArcGIS but ...
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3answers
153 views

Applying rotation before FeatureToRaster_conversion?

I am converting polygon shapefiles to rasters. With arcpy I am using the function FeatureToRaster_conversion. gp.FeatureToRaster_conversion(InFeatures, InField, OutRaster, InCellSize) This function ...
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756 views

How to extract breaklines from a given DEM?

Breaklines are very useful for describing a terrain - for example to build an exact TIN. My question is, how to extract these breaklines from a given DEM? I calculated the curvature (vertical) - ...
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3answers
5k views

Finding nearest raster cell value based on vector point?

I have two layers in ArcGIS: One is a vector point and the other is a raster layer. I want to append the value of the raster data grid to the vector point. The problem is the vector point is away from ...
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1answer
229 views

how to rename the band-names of a layer stack?

I created a layer stack of 20 images (all GTiff-files) using the gdal_merge tool in QGIS, available at: raster > miscellaneous > merge The result is a GTiff layer stack of the 20 images, but ...
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1answer
62 views

QGIS processing does not support jpg

I would like to work with the gdal functions provided in the processing toolbox. It is easy to call: import processing processing.alglist() ...
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7answers
6k views

Extract raster values at points

How can I extract values from a raster by points. I prefer not in Arcgis. I prefer in Qgis or Mapwindow or other open source gis.
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2answers
2k views

How to access each raster in a stack with a loop

I have a stack of rasters and I want to access each layer, combine each later with another file and finally export the resulting file as a csv file. Is there any way to do this with a loop? So far I ...
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1answer
28 views

My raster values are always changed to zero

I'm uploading a series of XYZ data points onto GIS and the co-ordinates are coming up fine, but some of the Z values are changed to zero - and in some cases, all! I've interpolated the majority of the ...
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1answer
93 views

Qgis - unwanted offset when using raster interpolation plugin

I'm using QGis and I have a set of points with a depth attribute. I'm trying to make an interpolation using the Raster interpolation plugin (Raster -> interpolation -> interpolation). But when I do so ...
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1answer
335 views

Is there a way to write single bands raster from multi-band layer faster in r?

I have 1000 multi-layer rasters and have to export each separate layer to a tif. Some friends recommended R to do the job. I used the following code: library(raster) namesVector<- c("layer1", ...
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2answers
141 views

How to reduce Polygon to Raster (Conversion) bit depth?

I have a polygon featureclass that I am trying to convert to raster format at a low bit depth (i.e. <8 bit unsigned). The FC contains 50,000 polygons which have five values: 1,3,5,7,9. I have set ...
5
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1answer
581 views

How to mosaic rasters in R?

I am trying to mosaic several rasters into single big raster in R. Using script that posted in http://stackoverflow.com/questions/15287807/how-can-i-create-raster-mosaic-using-list-of-rasters But, I ...
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73 views

Bi-Weekly NDVI data into monthly Datasets

I have NDVI data in both Ascii Grid format (0.250 degrees resolution) and raster format twice a month like: ndvi1981_07a ndvi1981_07b I would like to combine these bi-weekly values (average) into ...
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1answer
301 views

Hillshade tool in ArcMap returns terraced, pixelated image

I am applying Hillshade tool (ArcMap 10.1) to SRTM in Caucasus Mountains (border between Russia and Georgia). It gives me weird image with 'terraces' (see attachment). I reprojected SRTM from WGS-1984 ...