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

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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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39 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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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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How can I join several raster files using QGIS?

I'm new to QGIS. How can I combine multiple raster layers into one layer? The raster images are of different areas with very little overlap. The goal is to bring numerous town plats into one project. ...
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41 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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9 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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36 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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427 views

Tabulate area - Spatial Analyse

I am trying to calculate the amount (sqm) of land cover types (forest, water ect.) in 1045 buffer zones, all the same size (500m in diameter).. The buffer zones are polygons and the land cover is a ...
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70 views

How can I identify lines that intersect a certain raster layer area?

How do I identify certain roads ( of a line shapefile) that intersect with a layer that is produced from the reclassify tool (for raster data)? I am trying to identify which roads specifically are in ...
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22 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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16 views

Extracting many raster values for statistical analysis in JMP

To summarize: We have 28.5 million XY coordinates we would like to compare up to 6 raster values for, and prefer to look at those values in JMP. We are exploring interpolation methods in ArcGIS for ...
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35 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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77 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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20 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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1answer
254 views

Changing color of raster images based on their data values - gdal

Let's say I have 1 band raster images with Gray Color Interpretation and I want to change their color based on their data values. Data values -1, will be Blue, -0.5 will be Light Blue, 0 will be ...
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113 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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42 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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650 views

Calculate Percent coverage using another raster, with dif resolution and orientation

I have a 0.5 meter raster that defines presence or absence (cells are either 1 or 0). I have another 5 meter raster, which I created. I would like to calculate a percent coverage of the underlying 0.5 ...
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467 views

mosaic raster to file geodatabase yields missing raster sections

Since upgrading to ArcGIS 10.1 (SP 1) from 10.0, I've been encountering an issue when running the arcpy.MosaicToNewRaster_management() tool with output to a file geodatabase. I'm principally working ...
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62 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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25 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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24 views

What format are raster data files with data, db, overpict, vect, and WMS folders?

I have a type of GIS data but I don't know what is this type or how to open them. My data are formed by 5 folders: data, db, overpict, vect, and WMS. The main folder (I think) is the first one; it ...
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2k views

Get extent of Georeferenced Rasters in Python and output to polygon shapefile

I would like to create a shape file containing the extents of each of the rasters in a directory. Is it possible to capture the extent of a raster using Python? I have tried ...
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27 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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206 views

Using rasters/features created at 10.0 in ArcGIS Desktop 9.3?

I am tempted to go back to ArcGIS 9.3 from ArcGIS 10. For what I do, 9.3 is more efficent. I know I cannot open ArcGIS 10 documents (maps, scenes) and layers in 9.3 unless saved as 9.3 file, but ...
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259 views

Renaming multiple rasters with ModelBuilder gives errors 000622 and 000878?

I have 101 raster images stacked inside a folder. The Rasters are of arcinfo grid type (*.asc) while having a long string name 'NW2D_T100_05_base_depthXXX.asc' where XXX ranges from 000 to 100. What ...
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251 views

Polygon to Raster taking longer in script than in ArcMap?

I have a large dataset that I am working with. Basically I have a table with 900,000 records that I join to a geodatabase feature layer, then convert that to a raster. This process takes a total of ...
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420 views

Summarize values from a raster brick by latitude bands in R

I would like to sumarize (sum and/or mean) values from layers on a raster brick based on latitude bands (been using raster package). Been looking at the package documentation and didn't find a way to ...
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316 views

What is the easy way for extracting a dted raster file?

I have some SRTM data which was converted to dted file with GlobalMapper or ArcMap ascii to raster. I want to extract raster from vector with an easy way. I have tried "extract by mask" method but it ...
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3k views

Extract raster by mask output does not completely overlap the mask

I have a flow accumulation grid and a shapefile containing catchment areas. Now I want to do some calculations on them so I need to extract data from cells in the raster adjacent to certain catchment ...
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2k views

How to extract raster values and create new raster in Qgis?

I want to extract certain values of a raster image in order to create a new raster which then should only contain the extracted/chosen values. How to do this in QGIS?
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593 views

Extract multi values to point error

I am trying to extract values from my rasters (slope, aspect, landcover etc.) for my animal group locations. I used Spatial Analyst > Extract Multi-values to Points, but when I look in my attribute ...
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337 views

How to extract values from intersection of different size buffers with raster?

I have a polygon shape with buffers. However, the buffers are of different size from 4m radius to 15m. In total I have 7 different buffers. I have a landcover raster and I would like to extract ...
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1answer
225 views

Extract/Split raster dataset by attribute (OBJECTID)

I have a raster dataset with an attribute table generated from a series of image classification (unsupervised) and processing tools (majority filter + boundary clean). The attribute table shows pixels ...
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Ecoregions shapefiles: subsetting, extracting and summarizing data from raster

I am attempting to subset and project an ecoregions shapefile from : EPA ECOREGIONS my data set is found here: SHAPEFILES and RASTER When I run this code, two major problems occur: 1) I cannot get the ...
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143 views

I am getting NULL values when I use “point sampling tool”? [duplicate]

I am trying to extract values from a raster using a point shapefile, but I am getting NULL values. I think that NULL values are obtained because the Coordinate Reference System (CRS) are not the same ...
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31 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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38 views

Extract values to point - values not being extracted [closed]

I have a single band raster. When I use the information select tool I can see pixel values. I also have a shape file made up of points sitting over the raster. I want to extract the pixel values from ...
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QGIS Extract elevation data only for one country [duplicate]

I have a map built with a shapefile for country contours and a raster from .hgt files with elevation representation. How can I only select the area corresponding to the country? I found some thing ...
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1answer
130 views

Preserve attribute table while using Extract by Mask in ArcGIS

When using the Extract by Mask function on a raster with several columns (beyond value and count) in the attribute table, the resulting raster does not have all the columns (it only has value and ...
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29 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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27 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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83 views

QGIS print composer export excludes one layer

I am trying to export a map from QGIS print composer but the resulting files (I've tried all image, .svg, and .pdf formats) do not appear as the map did in the composer. It is as if one of the raster ...
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26 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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34 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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309 views

Making Shaded Area Polygon from HILLSHADE raster in ArcGIS Desktop?

How am I suppose to extract the values ( Value<=100 ) from this HILLSHADE raster, and then make the extracted values as a VECTOR POLYGON (shapefile) ---I'm using ArcGIS 9.3 (ArcInfo with all ...
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48 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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21 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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63 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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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 ...