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

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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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43 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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39 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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4answers
173 views

raster area calculation using python script

Hi I am a beginner to python programming in GIS and am trying to calculate the area of a raster. When I ran the program, I got error message below. I am also providing my code. Any help would be ...
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4answers
110 views

Measuring area of raster classes?

Are there any tools or methods in ArcMap that can measure the area of each level of the kernel density output? Note this is just a kernel density plot (not a shape file or polygon). Kernel Density ...
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1answer
31 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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2answers
34 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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36 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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132 views

Cropping or removing borders (not NoData) from multiple scanned and georeferenced maps (ArcMap or QGIS)

I have several hundred scanned maps in TIFF format, each correctly georeferenced and forming a large grid of images. The problem is that the border for each map is present - a white band, with a black ...
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96 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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37 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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89 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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109 views

Arcpy Subtracting rasters error - TypeError: 'unicode' object is not callable

I have a script which subtracts 2 versions of the same raster from each other (one newer than the other) and then extracts the additions & deletions that have happened. I created a simple test ...
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24 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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28 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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39 views

Convert colorized/styled vector (KML or qgis-project-origin) to raster and preserve the colorization

I can very rapidly create nice heatmaps (chloropleths actually) using qgis that I can then export as kml's that have the correct colorization when displayed on Google Earth, etc. I'm wanting to ...
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2answers
170 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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286 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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128 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
31 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
40 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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23 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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2answers
99 views

Display two-dimensional color gradient for two different quantities

I have two overlapping raster layers. One contains quantity A from 0 to 100, and the other contains quantity B from 0 to 100. I'd like to create a map displaying both sets of data at once based on a ...
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105 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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56 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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44 views

How can I use polygon grid to export raster [duplicate]

I have a polygon grid which consists of 100 square polygons. For each square I need to export the raster overlay. I have ArcGIS 10.0, FME 2014, Saga-GIS. Is there a suitable tool for this or do I need ...
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18 views

Oncoming intersection or intersection density

Through the use of Android and its on board GPS module, I am looking to calculate the density of intersections in a given area. Say 1 km x 1km. How would I go about accomplishing this? I am new to any ...
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46 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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57 views

How to view a raster in CartoDB?

What is the easiest way to view a raster in CartoDB? From the list of formats that you can upload into CartoDB, I noticed that .tif is available, so I've tried adding a GeoTIFF, but it says that ...
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73 views

How do I convert a .bil (and associated .clr, .blw, .hdr, and .stx) files into georeferenced rasters in R? OR to geotiffs using gdal_translate?

The title says it all. I've got a bunch of .bil files, which I can open in R using the raster command pointed to the path to the .bil file. But I don't know how to efficiently incorporate the ...
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55 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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29 views

How do you visualize change in rasters over time in CartoDB?

I have a series of satellite image rasters. I need to show the change over time of these rasters. Would the best way be to change the basemap with the click of a button for each? Has anyone got an ...
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87 views

Changing raster cells values inside of a polygon to the closest cells just outside the polygon!

I have been wrestling with this for a while and couldn't find out how I can do this. I want each cell of a raster inside of a polygon boundary to have the value of the closest cell just outside of the ...
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63 views

GeoTIFF created using ArcGIS for Desktop not displaying in Google Earth or Photoshop?

I originally had an IMAGINE Land Cover raster file that I opened in ArcMap. I used the Extract Feature from Raster to extract only the Developed class and saved it (still IMAGINE). Then I used the ...
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27 views

How to export query result on raster table in PostGIS

I did success query on a raster table in postGIS(raster data clipped by a vector polygon), now I want to view the query result in QGIS. But how to export the query result to another table. In vector ...
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38 views

Qgis Server, show Oracle Georaster dynamically

I have an Oracle Spatial database and I use rasters (SDO_GEORASTER). I can render some rasters on a web page with Qgis Server : when I render the maps on the webpage, it come from a qgis project ...
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60 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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3answers
190 views

Merging multiple rasters with the SAME spatial extent

So I began with lidar elevation data 1m resolution, and I performed a terrain analysis to extract specific ranges of elevation from the raster (1st picture is 0-1m elevation, 2nd picture is 1-2m ...
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82 views

Simplest way to limit the memory that the raster package uses in R

What's the easiest way to limit the memory the raster package uses in R to 5GB of RAM? Ideally I want any raster that exceeds this size to be written to the hard drive and analysed from a temporary ...
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28 views

Calculating GRID Statstics

I have a GRID raster dataset with no calculated statistics. I have tried building pyramids and calculating statistics with no luck. What am I missing? EDIT: For those who don't understand: 1. ...
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41 views

qgis raster style 'no data value' checkbox is ignored - what's a good workaround?

See bug report filed here: http://hub.qgis.org/issues/10236 Note the initial bug report got 'fixed' but that fix introduced this new error, so the issue was reopened a few days ago. Anyway, it ...
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2answers
91 views

Retrieve Elevation from Color in Raster DEM

This might turn out to be a newbie question, and that would be because I'm fairly new to GIS work, but extensive online searching, asking associates with some basic GIS knowledge and hours in various ...
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1answer
145 views

Step-by-step: How do I extract Raster values from Polygon overlay with Q-GIS or R?

I am writing my master thesis at the moment and am having the exact same problem as user Curley in this question: I first need to overlay a Corine 2006 raster with a polygon layer (2638 polygons). ...
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62 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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20 views

gt:VectorToRaster in Openlayers

i would like to opa vector table using "gt:VectorToRaster" a WPS function in Openlayers. my vector table is stored in Postgis 2.1 and published in geoserver. i need the code to do this, can you help ...
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71 views

Difference in vector / raster area measurements

I'm comparing raster and vector distance zones. So I created a line, calculated the Euclidean distance, and reclassified the raster to two zones: from 0-10m and 10-20m. To compare it with vector ...
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128 views

R plot raster with real colors

I'have a raster image from Scran25 IGN. In Qgis, it opens perfectly but in R (with rgdal or raster packages), I do not know how to keep the original colors like this exemple? I have tried ...
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40 views

how can we convert vector data to raster data in geotools

In my project iam able to open and save shape file. I want to convert this vector data to image format as a tiffimage plese help me the procedure to do the same.
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40 views

rasterize table polygon postgis 2.1

I would like to rasterize a postgis 2.1 polygon table, but I don't undersand how to create the SQL function syntax for ST_AsRaster. My vector table has 3 fields: gid, recharge, and geom. The SQL ...
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60 views

problem in scale of projected raster

I have a shapefile (my basin limit) and one raster file that I projected it to the shapefile coordinate system and set its cell size to 1000m(area=1Km2). my basin area is 5400 Km2 and it should ...