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

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Extract by Attributes in Model Builder, “Table Name is Invalid”?

I'm attempting to use "Extract by Attributes" in model builder as part of a larger model. I'm trying to pull 6 different attributes out one by one in order to create random points within their areas. "...
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382 views

Is the QGIS connection with ArcGIS “mapserver” still working?

I would like to add the Ocean Basemap to QGIS. I also found the other posts and I followed this procedure: http://hub.qgis.org/wiki/quantum-gis/Arcgis_rest Hovewer when I put in the Python console ...
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315 views

Extracting point data for each lat and long from raster file into a dataframe

I have gridded data files ( see sample -each file consist of monthly precip and is label pYYYYMM) https://www.dropbox.com/sh/63z166tjxyu12s5/AAAs3Ccn1zdVoBYMj8Y1o303a?dl=0. I am trying to extract ...
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125 views

How to merge two rasters when are on the same place

I have two rasters in GRASS GIS. first : raster of DMR, raster picture of relief - created from high values second : raster of buildings where pixels of every building have value of high of this ...
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161 views

moving window regression on raster stack in R

I want to perform a moving window regression on every pixel of two raster stacks representing Band3 and Band4 of Landsat data. The result should be two additional stacks, one representing the ...
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352 views

Align vector and raster layers with D3

I have a geocoded raster image that I want to use as the background to a vector map with D3.js. The screenshot shows the layers in QGIS (grey is raster). Here's the markup for the map: <div class="...
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96 views

Weighted Overlay final raster to indicate inputs

I have a weighted overlay that identifies the most important areas in a corridor scaled from 0 - 100. I would like to be able to click on a cell and be able to identify which input rasters contributed ...
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135 views

Mosaic to raster 16BIT Error 999999

I am using ArcGIS for Desktop 10.1. I am trying to merge a few 16bit rasters by Mosaic to New Raster. The problem is it makes me do only a 8bit output making me lose pixel data bigger than 255 and ...
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289 views

Directly querying a raster

I've done tons of work within ArcGIS to analyze and process rasters. I'm pretty well knowledgeable on that subject. A question has come in from my coworker who is attempting to populate elevation data ...
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114 views

How to change sign of z value in a large dataset?

I have data in an XYZ format (saved as a .txt file) that I am importing into ArcGIS and then converting to a raster using the point to raster conversion. However the Z field in the data represents a ...
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302 views

Receiving NULL values from Point Sampling Tool in QGIS

I am using QGIS 2.8.2. My project includes a raster layer of flow depth representing the output from a flood simulation (.DAT file). It also includes a vector layer of points representing the ...
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290 views

Single WMS from single mapfile with several rasters in MapServer

I have several rasters in a single mapfile, I put them as layers like here: LAYER NAME "Layer 1" GROUP "All Layers" TYPE RASTER STATUS ON ...
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2answers
135 views

Is it possible to georeference raster stored in Postgis?

I'm looking to store a huge raster aerial image (400 Gb) into Postgis, but before storing it i like to know how i could georeference or rectify raster stored in postgis ? is there any Qgis plugins ...
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1answer
63 views

Display coastline

I have a raster converted from shape file(tool point to raster). Can anybody prompt, how to display coastline? I can use contours, but are not focused at condition "elevation = 0". Is there any simple ...
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2answers
357 views

QGIS: why does clipping a raster alters cell size?

Using QGIS V 2.2.0 (OS-Windows 8), I need to prepare raster files (ESRI ArcInfo Grids) to be later used in a species distribucion model using MaxEnt. Each of the original raster files (environmental ...
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3answers
1k views

Unable to read raster into R: 'TIFFReadDirectory:Failed to read directory at offset'

I'm getting a weird error when trying to read a raster into R. >r <- raster('myraster.tif') Error in .local(.Object, ...) : TIFFReadDirectory:Failed to read directory at offset 2606110 ...
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4answers
1k views

Checking if polygon fits inside another polygon using ArcGIS or QGIS?

How do I check if one polygon fits inside another polygon? Furthermore how do I automatically check if one polygon fits in other polygons of my shapefile? I have a shapefile with thousands of ...
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44 views

Combine Raster and Feature Class selection

I've been working on a quite complex analysis with ArcGIS 10.2. But now I'm stuck at a problem... I have a raster file and a polygon feature. The Raster file stores information about Zmax, Zmin and ...
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67 views

Multiply two lists of raster from two subfolder

I have two subfolders, which contains rasters for each country but which express different variables. I am trying to figure out a way to Loop a multiplication of each raster into a folder with its ...
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2answers
331 views

How to automatically calculate maximum cell values contained within polygons?

I've got a dataset made up of a large range of polygons (about 70 or so) which represent structures. I also have raster layers which detail a flood depth across an area. The floods depth raster has a ...
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2answers
130 views

Reading next row of *.txt column inside ArcPy for loop for batch process?

I'm not sure how to approach this problem with python, but in plain english, I'd like to rename rasters with the names given in the *.txt file (see screenshot) and concatenate the basename given by ...
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129 views

Converting lat,lon & solar data in CSV to raster using Python?

I have a csv file with lat,lon and solar radiation data. I am trying to convert it to a grid/raster format so that it can be used with a raster population data set that is in ascii format. How can ...
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280 views

conversion of *.tif file format to *.hdr file format

I have clipped DEM of a region from SRTM data. It is in .tif format. Now I want the same file in header format (.hdr). How can I convert *.tif file to *.hdr file?
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45 views

Georeference a computed tomography image without changing its proportions in QGIS

I have several images obtained from a Micro computed tomography (mCT). The scanned elements are human teeth. In a particular mCT slice, I have introduced a cartesian plot with its X and Y axis. The (...
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174 views

Calculate minimum area where x% of raster value total is concentrated within polygons

I have a raster layer (chlorophyll concentration) and a layer of non-overlapping polygons (regions of the ocean). For each polygon, I'd like to calculate the area where the majority of chlorophyll is ...
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33 views

change from NAD 1983 to some PCS?

I want to ask how to change the coordinate system from NAD 1983 to some Projected coordinate system. I tried to change this DEM file to WGS 1984 (all of them) but when I did that my scale becomes 1:4. ...
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40 views

Raster loading in web application

I'm making a GIS web application. I want to give the user the option to choose the raster to display on the map on the basis of date. I have daily rasters of 3 years. I'm using ArcGIS Server. Any ...
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1answer
4k views

How to extract specific values to a new raster in ArcGIS?

I am new to ArcGIS so I don't even know if I am using the right terms in the question. Please excuse me! I have this map stored in gdb format. As I opened it in ArcGIS 10, I see that it has data for ...
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1answer
96 views

Cell statistics sum resulting cells to indicate original input rasters

I have 5 rasters (habitat suitability models for 5 diff species) that i have set to the value 1, I have then used the Cell stats (Arcgis10.0) to add the rasters together so I can see the overlap ie ...
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231 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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2k 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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68 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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70 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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54 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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129 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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125 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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171 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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1answer
62 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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403 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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79 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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296 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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1answer
235 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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53 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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1answer
26 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. I'...
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530 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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148 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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135 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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47 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] ...
2
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1answer
46 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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103 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 ...