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

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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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88 views

Extract raster value to polygon

I am trying to extract raster values within multiple polygons. It would be nice if I could choose between say the maximum or an average raster value within the polygon. For example, I have created ...
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43 views

Calculate cover loss between years using r.mapcalc

I am working on forest cover raster data for 2 years and am interested in areas with >5% loss in forest cover. I am pretty new in GRASS GIS, so any suggestions for how to create a difference map of ...
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28 views

How to calculate the area of a raster within a polygon which is greater than a specified value?

I'm using QGIS (2.8.1-Wien) and I have a raster layer showing chlorophyll concentrations in the ocean. I have also defined number of regions of the ocean using polygons. What I'd like to calculate for ...
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32 views

How to create a map series of different rasters (same location, same legend)?

We have hundreds of raster images at the same location (same dimensions, pixel size, projection, etc.). We would like to display each one in its own map using the same legend with the same vector ...
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26 views

Stacked with “expected a raster or layer name” error

I am using the following python script snippet but I get a TypeError: expected a raster or layer name on the commented line below. I could not find a solution about how to convert the A1 raster (that ...
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73 views

How to remove outlying islands from a DEM raster?

I have a raster image that looks like this (see below) How do I remove the outlying islands and keep only the central main island in the image. Is it a geoprocessing clip function? I am using QGIS ...
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49 views

Using ModelBuilder to Make Composite of NDVI Rasters in ArcMap?

I have got a large number of landsat raster data. I need to prepare composite raster and Ndvi rasters from the band Rasters which I have. I normally use Image analysis in ArcMap. I wanted to know how ...
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47 views

How to use the con statement in raster calculator to include a raster as a condition in an existing raster

So, I'm busy doing an assignment where we have to use a Weighted overlay to generate a raster of suitable places to plant crops. I've put all the factors in the weighted overlay and generated my ...
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27 views

Extracting area from DEM Raster?

After applying constraints to the DEM I polygonised the raster (using GRASS r.to.vect.area) The result is shown below with a lot of vector with resolution = [30 * 30] Is there any solution to make ...
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78 views

Accumulated value from many rasters python/arcgis10

I need to calculate an accumulated value of temperature (as an additional raster) from many rasters. Is there any option to do this in ArcGIS 10 or any hints for a python script?
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26 views

Analyzing homogeneity of raster values within polygons

I've been working with raster data of NDVI for agriculture plots. I'm testing the use of descriptive statistics (e.g. range and standard deviation) to observe any variations between plots (I think ...
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52 views

Convert polygon to raster and give value to null cells

Is there a way to convert polygon features to raster while also populating null cells with a specific value? As in, can I create a raster from a polygon shapefile and have the tool populate all null ...
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52 views

gdal_array.SaveArray() leaves dataset open in Python

When I use gdal_array.SaveArray() to create a raster, the newly created dataset appears to stay open in Python, preventing other processes from working with it. For instance, consider the following ...
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22 views

Error 010240 when calculating mean of a list of rasters - Cell Statistics

I'm trying to calulate the mean value of a list of rasters but I am always getting the following error: RuntimeError: ERROR 010240: Could not save raster dataset to < value > with output format ...
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35 views

Combining information from one raster with another raster

I have two rasters, A and A1. Raster A is the image below that is greenish and has the following attribute table: The table has two fields that I need: Value and class_name Raster A1 is the ...
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15 views

Converting CALS type rasters for Arcmap?

I have a bunch (think 400+) scanned old portions of maps that are in .cal format, apparently a CALS type raster format. I am able to open them in Autocad Map 3D, but Arcmap does not recognize them. ...
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29 views

weight a raster by another for a model ( R/ arcgis/maxent)

I have an idea in mind for my project but I can't figure out how to do it in R and Arcgis. Basically I would like to do a weight a raster by another for my maximum entropy model. -I got a raster ...
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12 views

joining attributes for .img files in erdas

I have numerous .img files of the same region and spatial resolution. In Imagine I would like to join all the attributes together into one .img that I may import into r for model predictions. Not ...
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63 views

How to round pixel values of a raster in QGIS?

I have a raster with float number values for example: 2.544459104537964 and I want to round these up to intergers. I have seen other posts on ArcGIS like this one but when I use Raster Calculator in ...
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2answers
64 views

Calculating forest connectivity for raster

I'm trying to calculate some sort of forest connectivity value for each pixel in my land cover classification. I would like to do this by calculating how many other forest pixels are directly ...
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60 views

How to separate details by color from raster?

How to separate details by color from raster? Is it possible in ArcGIS or any other software? I have tried Spatial Analyst. I want to use RGB .tiff image which is scanned map. It consists of all the ...
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30 views

Help Summing Raster cells to equal circles with a specific sum

So I have this application user density data that I've collected. Each gps point has a user density associated with it (for example: 150 users within a 1 km radius, which calculates to users/[pi*R-sq] ...
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35 views

Sequential rasters - when did point x change

Using ArcGIS 10.1 with Spatial and 3D Analysts, and Python 2.7 I have a series of reclassified rasters in which every cell is either one or zero. I need to programmatically create a single raster ...
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23 views

GDAL Python and postgis raster?

I'd like to create a postgis raster using GDAL and python. I can get the driver easily: drv = gdal.GetDriverByName("PostGISRaster") But how can I create a new raster table? I can't find any ...
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36 views

Modifying DEM elevation data in QGIS using a polygon

I've tried searching through the existing questions but am struggling to find a succinct answer to what I am trying to achieve. For background, I am running a flood model in TUFLOW to help support a ...
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27 views

How to combine two rasters based on the relationship to a polygon mask?

I am looking to combine two single-band, 1-bit rasters of the same spatial extent based on their relationship to a polygon (mask). The image shows a polygon displayed with a cross-hatch and the two ...
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143 views

Calculate scale of a raster

A raster has a cell size of 200 meters. What is the corresponding scale of the raster? New to GIS, using ESRI, semester is almost over but this one question is confusing. I didn't think you could ...
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29 views

In ArcSDE, SQL Studio Manager 2012, How to get pixel data using a point layer?

I was using 'where' and 'ST_Intersects' with polygon data to get values 'under' my point layer. Example: Select rd.[FORESTNAME] as Forest, Count(Distinct morel.[OBJECTID]) AS Observations From ...
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33 views

How to check if a file is a valid raster image?

How to check if a file is a valid raster image? Valid in the sense of not being corrupt, the file record is complete. The GIS corollary to "zip --test somefile.zip" to test if an archive's integrity ...
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22 views

Using mask to several raster datasets with same cell size, extend and row/column in ArcMap?

I have a raster dataset "substrate_W84" that I would like to use as a mask in order to create several raster dataset with the same cell size, extent, row/column (to be used in Maxent). ArcMap 10.0 ...
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26 views

Uploading raster to ArcGIS Server dynamically

I am building an new web tool related to agriculture research, this tool is linked to another backend GIS process done in c# and ArcObjects. I want to find a way to visualize this backend output ...
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13 views

Using QGIS to create a single # band raster Image [duplicate]

I recently downloaded some Landsat Images. They are in GeoTIFF format. The images are in the different bands. How can I combine them for example if band 1 is Red , band 2 is green and band 3 is blue, ...
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24 views

How to make Feature to Raster tool run faster

Suppose you have a feature class that you need to convert to a very detailed raster (where each cell size is quite small). With a cell size of 0.0092908447 in the Feature to Raster tool, the procedure ...
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51 views

How to create shadows of buildings with r.sunmask?

I need to create image-raster with shadow of relief and shadow of buildings in one. I know how to create shadow of relief but how i can create shadow of buildings with r.sunmask? I dont know how from ...
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62 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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47 views

Hosting Rasters as a Tile Server

I am currently trying to serve a Raster Datasheet made from several Geo(TIFF) files but I am unsure about how to go about it as I'm quite new to GIS! I need to host it online so that clients can ...
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34 views

How to run Focal Stats on specific values in python

I'm a beginning programmer and am new to the site but it has helped me quite a bit so thank you! I'm trying to recreate a raster calculator operation using python scripts but am having a hard time ...
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37 views

How to expand a floating point raster by one pixel

In ArcGIS 10.2.2, I have a floating point raster of oceanographic data that boarders a coastline. Due to the jagged edge of the coast, the raster edge only sometimes overlaps the coastline and leaves ...
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33 views

How to set floating point raster values to NoData when raster does not have valid statistics

I have a raster with some values of 99999 that I want to set to NoData in Arc 10.2.2. I've tried using the SetNull dialogue box, the SetNull arcpy function, and the Raster Calculator dialogue box as ...
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2answers
39 views

gdal_calc : fails with value 0?

I working to invert values of a one-band tif files (download sample). If i use 254 it works: $ gdal_calc.py -A ./shadedrelief.tmp.tif --outfile=whited.tmp.tif --calc="254*(A>180)" 0 .. 10 .. ...
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46 views

How to view a postgis raster query in QGIS

I have successfully loaded a large number of .asc images (>2800 200x200 tiles) into a Postgres table with PostGIS 2.1 support. The new table appears in QGIS's DB Manager and I can add the whole image ...
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42 views

qgis2threejs - rendered surface edges “bleed”

I am using qgis2threejs on some raster datasets representing different potentiometric surfaces of aquifers. The rendered 3D images from qgis2threejs have the edges of the surfaces "bleeding" down to ...
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1answer
50 views

Extracting point information from raster in R

I'd like to work with climate data available from here and extract values of certain locations (for which I have lat and lon). This is what I've done so far: library(SDMTools) library(raster) test ...
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63 views

How can I loop through a list to create rasters and write them to .tif files?

I received 3 .mat files that each contain several daily maps. I need to take them and get them into ArcMap (10.2 if that matters) as a .tif with spatial information. I have already used the R.matlab ...
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76 views

Getting information out of an ArcGIS .lyr file

I'm using ArcGIS 10 and I downloaded a Raster layer from here: http://bioval.jrc.ec.europa.eu/products/glc2000/products.php When I unzip it I get the following files: 1 Aux-File (15KB) 1 ...
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Using QGIS in medical Science? [closed]

I was wondering if anybody would be interested in collaborating? My Idea is using QGIS to analyze and quantify Immunofluorescence raster images of cells from human serum.
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52 views

How to mosaic to new raster for multiple DEM tiles?

I took some DEM files and turned them into raster .tif files, i then tried to Mosaic them together using the mosaic to new raster tool and i keep getting two problems consistently, there seems to ...
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174 views

Classifying DEM according to elevation in R?

r<-raster("DEM.tif") How to do the classification based on every ten meters for example and have different colors too?
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139 views

Generate PNG/JPG maps from multiple ASCI/GeoTIFF in Python/GDAL

I need to generate maps (saved in PNG, JPG or PDF) from raster files (for each file - one map) which meets following criteria; * each map has exactly the same color pallette, so that it will be easy ...