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

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Create time series graph with multiple rasters

I need to create a time series graph for a few random cells with known underlying attribute such as "forest" or "agriculture" based on the VCI (Vegetation Condition Index). I have been reading and ...
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2answers
244 views

How to extract raster pixel value in ArcGIS

I am dealing with some very large geotiff files (the whole of Canada at a 250m resolution) and is having trouble to extract the pixels value as I need to do some calculations for mapping ecosystem ...
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9 views

Is Output Cell Size Environment the same as Resample tool?

I have a raster catalog that contains hundreds of rasters (10 x 10). I need to perform Cell Statistics SUM on all the raster. End user able to specify under what cell size the want to perform the ...
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1answer
23 views

Array written by GDAL with Python script has numbers read as “nan” by QGIS?

I would like to write an array to a geotiff with Python script using the GDAL module. When I try to do something simple like copying an existing GeoTiff via reading it to an array, then, writing to a ...
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1answer
1k views

Problem in importing raster data from PostGIS to Geoserver

I am using Opengeo Suite 3.0.2, PostGIS 2.0.3 and PostgreSQl 9.2. I am trying to import raster data from PostGIS to Geoserver but facing an error. I follow this tutorial link to import the raster ...
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1answer
26 views

relating land cover raster to vector data

I have a land cover raster basemap that covers different land cover/uses in Europe to 100m resolution and a separate Excel legend file. Separately I have a point shapefile with the details and ...
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5answers
4k views

Reproduce raster with same extent, and same number of columns and rows?

I have two raster A and B. A and B have the same grid size but different extent. How can I make A have the same number of columns and rows, as well as the spatial extent of B?
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4answers
3k views

Increasing speed of crop, mask, & extract raster by many polygons in R?

I'm extracting the area and percent cover of different land use types from a raster based on several thousand polygon boundaries. I've found that the extract function works much faster if I iterate ...
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2answers
407 views

Really slow extraction from raster even after using crop?

I have a large raster file (245295396) cells and stacks of rasters having 4 layers each which lie in the extent of this large raster. To start with I am trying to get value from one stack (3 channels) ...
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1answer
32 views

QGIS “Raster->Georeference” menu item not showing up

I am using QGIS 2.12.0 Lyon. I have installed a plug-in called "Georeferencer GDAL" and the version of that plug-in is 3.1.9 . [I am working on a Mac which is running OS X Yosemite 10.10.5.] I am ...
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1answer
313 views

Unsupervised raster classification using GDAL

Is there an equivalent in GDAL to the Arcpy ISO data unsupervised classification tool, or a series of methods using GDAL/python that can accomplish this?
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2answers
17k views

How can I convert data in the form of lat, lon, value into a raster file using R?

I have a data set of values over a km grid in the continental U.S. The columns are "latitude", "longitude", and "observation", e.g.: "lat" "lon" "yield" 25.567 -120.347 3.6 25.832 -120....
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9 views

PostGIS - raster - bit operations

I have a raster data in the database in separate rows. I would like to select 2 rows and do a bit operation with them (like |, &) and store the result in memory as a query output. Is this possible?...
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1answer
186 views

QGis export part of map (box with coordinates) as raster

I would like to export a map of Switzerland (as part of googlemaps) to use as a background for a graph, but I need to know exactly where each corner of the map corresponds to (wrt spatial coordinates)....
3
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1answer
187 views

Export Stretch Function values - Arcpy

I'm looking for a way to export Stretch Function values from images that’s stored in a Mosaic dataset. Not values from the whole set, but specific stretch functions per image. The set is stored in ...
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1answer
254 views

How to download the MODIS data from R using MODISTools library

I want to download MODIS product MOD13Q1 to use the Scientific Data Sets (SDS) layers of "250m_16_days_EVI", "250m_16_days_pixel_reliability". MODISTools library in R software provides the capability ...
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2answers
216 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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0answers
8 views

ArcGIS trim-mean interpolation

I am trying to create a raster dataset from regularly spaced point data. I would like to use a trim-mean function rather the more standard mean function. Is it possible to do this?
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1answer
17 views

ASCII Raster Statistics?

I have downloaded the following precipitation data in .nc4 format(attached). I have opened the 'PRECIPITATION' variable in the file in QGIS and I have made a note of its statistics. As working with nc ...
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1answer
975 views

Converting DEM to Floating Point Raster (FLT) using QGIS?

I am looking to convert a .DEM exported from AutoCad to a floating point raster file type (.FLT) utilizing QGIS to implement in HEC-RAS Mapper. This is accomplished easily in Arc using the Raster>...
2
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1answer
22 views

How to represent seasonal variability in a single global NDVI map?

I have twelve monthly MODIS datasets for a 1 year period (http://neo.sci.gsfc.nasa.gov/view.php?datasetId=MOD13A2_M_NDVI&year=2015) and wish to combine all the data into a single map highlighting ...
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1answer
38 views

Clip raster with shapefile and set a value outside the mask

I want to clip a raster using a shape file with the command: gdalwarp -cutline INPUT.shp INPUT.tif OUTPUT.tif from this answer. However I want to set the pixels outside the mask to a particular ...
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2answers
22 views

Geoserver WMS raster problem

I have the following problem: The edge of the imagemosaic is not fit well, Im using geoserver imagemosaic tool to serving orthophotos through wms server. Is it a CRS, Bounding Box problem?
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51 views

Working out percentage of different raster parcels in polygon?

I have a raster layer (LCM2007) that contains 24 classes of landcover and a shapefile, polygon, which represents areas in a survey. I want the area, or percentage, of each class in each area. For ...
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15 views

Failed to create raster dataset using ArcObjects?

I am currently unable to create a raster dataset. These are the 2 functions i have for creating the raster dataset but it seems to always throws an error "unable to create raster dataset". After ...
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2answers
57 views

Copy resolution extent CRS metadata from one raster file to another using raster R

I have two geotiff raster files, one has all the metadata information and in the other the information was lost. I know that all the metadata information was exactly the same so I want to copy it from ...
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0answers
15 views

Calculate Raster with value from table

I would like to multiply all the values within a raster layer with one value, which is written in an *.csv table (it is the only value in this table). How can I do that?
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1answer
680 views

How do I combine bands in a tiff then convert to grayscale?

I have a large mosaic of tiffs in which I need to do the following: -Combine bands 4,3,2, for an infrared image then convert the image to grayscale without producing another dataset -This is easy on ...
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2answers
533 views

How to get easting & northing of cell in raster using ArcPy?

It might be very simple task. But I would appreciate if someone can comment on How I can get easting and northing of a single cell raster using arcpy as this value is used for in further steps.
2
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0answers
23 views

How to Serve a Cached/Mixed Raster to Geocortex

I have never used a Cached/Mixed Raster format before, but I had these air photos given to me and I have to get them served up to our Geocortex App. I've been trying for weeks to covert it to a JPEG ...
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0answers
17 views

Select options in ModelBuilder progress?

I would like to create a model where the inputs will be two rasters (natural areas, agricultural areas). Each of these rasters will go into a raster calculator (the user will decide what raster ...
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1answer
25 views

Raster time series smoothing package using R

Does somebody knows if exist a package in R specifically for raster time series smoothing? I´m using aproachs like this one (using the equation suggested by Hamunyella et al., 2013) for (i in 2:(...
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2answers
875 views

Histogram Matching using Python to improve mosaicking process of multiple overlapping rasters?

I am trying to do histogram matching using Python to improve the mosaicking process of multiple overlapping rasters. I am basing my code on that found at: http://www.idlcoyote.com/ip_tips/histomatch....
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1answer
1k views

ArcMap 10.1 - Tabulate Area tool “doubling up” for Overlapping Buffer Zones

This question is related to a previous question I asked: Raster Version of Spatial Join (one to many) I used the Tabulate Area tool to crosstabulate values between an overlapping "buffrast" raster (...
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1answer
72 views

QGIS set default style for layers based on name

I know that it is possible to apply default fill/line/point and colour ramp styles for layers within a project, However... I have a model which spits out raster layers with defined names (e.g. ...
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16 views

Pixel based 10 year NDVI time series

I would to do pixel based 10 year NDVI time series analysis using MODIS data. I’ve 3 seasons in a year. Should I average all values in the study area per season?
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30 views

Improving Clip Raster workflow in QGIS?

I've tried to come up with an open-source equivalent to the following process in ArcGIS 10.3: Spatial Analyst Toolbox > Extract by Mask target input: 1" SRTM DEM in EPSG 4019 mask layer: single ...
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0answers
21 views

Resample raster to lower resolution

I am trying to resample a forest cover raster with high resolution (25 meters) and categorical data (1 to 13) to a new RasterLayer with a lower resolution (~ 1 km). My idea is to combine the forest ...
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0answers
15 views

Interpreting output from PCA tool of ArcGIS for Desktop?

I am looking for some assistance on interpreting the output from a PCA run in Arcmap. My data is comprised of 6 raster bands representing biophysical elements in the marine environment (SST, ...
1
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2answers
51 views

Can I extract circular buffers from polygon layers?

I have been working in QGIS with a large and detailed shapefile where remaining forest fragments are represented as polygons. I would like to extract circlular buffers, of various radii, from this ...
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1answer
43 views

Python Gdal write virtual raster

Is there a python module to create Virtual Raster (.vrt) xml files? Rather than writing text strings to a file, I'd like to know if there is an automated way to do this.
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7 views

How to do not display Nodata values on IMG raster

I have a problem when I try to visualise (in ArcGIS 10.1) a raster file on IMG (ERDAS IMAGINE) format. The NoData values are displayed in black and I cannot find a way to do not display them. I've ...
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1answer
31 views

How to doing spatial join for several rasters

I have four rasters, each of 32 bits (single band), with the same cell size, the same number of rows and columns and identical extension. I need to make something like a "Spatial join", I mean, I need ...
2
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0answers
49 views

Extracting Mean from Raster and Writing to Table in ArcPy?

I am simply trying to extract the mean of each raster within a geodatabase and write the value to a table. I have done this successfully with another set of rasters, but now I keep getting the ...
4
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1answer
64 views

How to selectively generate averaged raster layer from 5-year data raster layers in QGIS?

I would like to merge 5 years of world ocean surface productivity data raster into 1 averaged raster in QGIS. However, not every pixel has data in every year. To generate the raster layer with the ...
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27 views

Merging DEM file generted many negative value in QGIS

With four DEM files downloaded by Python Elevation package, I merged them in QGIS 2.8.3. I use raster-> Miscellanaous -> Input direction, no more attribute was added. The four dem data has ...
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47 views

How to calculate raster area or number of cells for multiple classes in a raster?

I have a raster with many classes and I want to know the area or the number of cells for each class. I found quite a few posts on this topic (see links below). None of the suggestions matched my ...