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

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21 views

QGIS raster no data value changed to -inf when viewing at smaller scale

I have a raster with some no-data cells. I want to visualise raster values using a colour map and set the no data values to transparent. I am attempting to do this using the transparency tab in the ...
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1answer
185 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 ...
2
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1answer
34 views

Why is ArcMap reverting 4-band raster settings?

ArcMap keeps redrawing my 4 band false colour image in standard 3 colour bands. As you can see below I have my 4 band data set to auto display as (4,1,2 - infrared, red, green). When I bring in an ...
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57 views

Get counts in grid cell for multiple values

I have 500+ polygon shapefiles with nationwide coverage. Each shapefile has possible record values of 0-4. I want to get the value that intersects each grid centroid and then get a total count for ...
3
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1answer
33 views

Problem with automated data storing during raster::crop (‘legend’ is not a slot in class “RasterStack”)

I am working with a set of raster layers containing CHIRPS monthly rainfall amounts over Africa. For purposes of reproducing the below code, I staged the decompressed tif files on Dropbox. Now, ...
4
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1answer
67 views

Altering elevation of specific cells in raster layer of QGIS?

I'm looking to alter the height of some cells within a raster and it's been suggested that I do this by creating a polygon layer and use that as a mask to alter only the heights of cells within the ...
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1answer
50 views

Find NoData values inside a polygon area from a raster

I have a raster (representing a polygon in black) which contains NA values (represented by white pixels) that are located inside the polygon and outside the polygon. How can I get the index value ...
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1k views

Enabling georeferenced TIF file to rectify in ArcGIS for Desktop?

I have added a TIF file (size 1,433 KB) in ArcGIS 10.2.2 and defined numerous georeferencing points, with the aim of creating a raster file for conversion to polygons. However, on clicking the ...
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24 views

Converting data from data frame into raster file using R?

I have the following data frame (long, lat, value) (all coordinates are within Colombia): Spoints: x y z 1 -75.67083 7.57916667 7.328901e-19 2 -74.59583 ...
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1answer
26 views

Finding and loading global population density raster data into R?

I am using the Bioclim dataset for a maxent project right now, but I want to add demographic predictors along with climatic ones. I have the 19 layer raster data from Bioclim and I'm hoping to use the ...
0
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1answer
36 views

I want to have two raster data sets overlay

I am using ArcGIS 10.3 I have 2 raster datasets with different coordinate systems, but they are the same county (just different databases). When I add them to the same map layer they are far away ...
0
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1answer
342 views

Combine overlapping rasters in gdal_calc.py, taking the maximum value from each pixel?

I want to combine 3 overlapping rasters to create 1 raster. Each have the same dimensions, resolution and CRS. I want to populate the new raster with the maximum value from each of the layers. ...
2
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1answer
30 views

Raster brightness, contrast, saturation in PyQGIS

I'm trying to find a way to change these properties (especially contrast and brightnes) and I've found a QgsBrightnessContrastFilter class, but I can't fugure out how to apply it to my raster layer. ...
0
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1answer
35 views

Crop Raster from using Polygon shapefile in R

I am trying to crop a raster by a polygon in R to the state of Sergipe-Brazil. My raster is a raster brick criated by 7 .tif files which are EVI (vegetation index) time series. Since the EVI archives ...
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18 views

Converting from ellipsoidal heights to orthometric heights (EGSA87)

I try to conver from ellipsoidal to orthometric heights with arithmetic function. In input raster 2 i put WGS84.img from \peodata\geoid folder.The results are not right. And now i have the question. ...
3
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2answers
225 views

Group adjacent polygons with similar (but not same) attributes

In ArcMap 10, I have a few dozen tiffs with cells that represent habitat area that has been burned. Each burned cell has a Julian date of the fire associated with it. I want to end up with polygons ...
3
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1answer
65 views

Create polygons of the extents of a Raster in R

I want to create two polygons. One is of the rectangular extents of my raster. I know I can obtain the extent of the raster using r <- raster("band5.tif") e <- extent(r) but don't know how ...
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1answer
27 views

How can I blend DEM rasters with GDAL?

I have several DEM rasters in different projections and at different resolutions. The rasters are not rectangular, but they have appropriate NoData values. They overlap enough that I should be able ...
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1answer
44 views

Why do we georeference from the image to the shapefile (and not the other way around)? [closed]

Why do we georeference going FROM the image, TO the shapefile (and not the other way around)?
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1answer
228 views

What exact format do I need to have for the inputs to make Path Distance work?

I am trying to run the Path Distance tool in ArcGis 10.1. Ideally I would like to utilize Tobler's hiking formula anisotropic approach to slope and a land cover cost surface to calculate the least ...
1
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1answer
35 views

How to speed up raster2pgsql?

I'm trying to upload a 37 GB raster dataset to PostGIS. The raster is out-of-db (-R option), so the actual pixel values are not stored in PostGIS. I'm using this command: raster2pgsql -s 25833 -C -I ...
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2answers
1k views

GDAL/proj4 equirectangular projection coordinate system units assumed by OGRSpatialReference and GDALDataset::GetGeoTransform()?

How do I configure my OGRSpatialReference object to specify an equirectangular projection system http://en.wikipedia.org/wiki/Equirectangular_projection where the affine geo-transform matrix (provided ...
2
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1answer
26 views

Create MosaicDataset with 12 Bits

I'm using ArcGIS 10.3.1, and I want to create a mosaic dataset, but my rasters are in 12 bits, and a mosaic doesn't have this option. What can I do?
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19 views

Find Maximum value per month in rasterstack/brick and corresponding timestamp R

When dealing with raster images, I found the raster and rts packages in R to be very flexible for analysing my raster data unlike ArcGIS. In my learning efforts, I have had to do some ...
4
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1answer
253 views

How to compute NDSI in ArcGIS for Desktop?

How do I compute a Normalized Difference Snow Index (NDSI) in ArcGIS's Raster Calculator? I have a Landsat 8 scene (hdf4 format) that contains derived surface reflectance band-by-band. Each band is a ...
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1answer
25 views

Importing South African NGI OSM imagery xml file now unsupported by QGIS

Here in South Africa we at our very small company often make use of this simple xml file (downloadable from http://aerial.openstreetmap.org.za/aerial-osm-org-za-tiles.xml) to link to these imagery: ...
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1answer
38 views

smallest number of cells classified in a raster

I am using ArcGIS 10.3 and I ran con statement in the ModelBuilder within ArcGIS. I have an output raster (2m*2m) classified into four different classes. The raster has small pockets of 4 classes. I ...
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1answer
326 views

How to use GDAL to burn a selected value from one raster into another?

I think this should be a relatively simple process, but I'm not quite sure how to approach it. I have a shapefile containing 1000's of polygons. I also have 19 rasters. All of the polygons fall ...
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2answers
33 views

Append daily rasters to monthly lists in Python Arcpy

I'm trying to go over a folder of geotiff rasters where the last three digits of the raster name is the julian date and I want to append the correct days to monthly lists (Jan-Dec) and then run Cell ...
2
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2answers
795 views

Trying to run raster calculator to build an expression for ls factor

I am trying to run a raster calculator, but it failed. I believe that ArcGIS 10 does not understand when I use the variable resolution. What do I need to put in its place? I took the equation from ...
2
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3answers
84 views

QGIS automatically set transparency for (#000000) pixels and save *.qlr

Starting with FME, i convert some hundreds of geotiffs to jpeg2000. The jpeg2000 writer does not support nodata-values. Adding the data to QGIS gives me these black (#000000) areas when rasters are ...
3
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1answer
128 views

Selecting multiple attributes, greater and less than

I am trying to select by attributes from a polygon shape file. I need to select areas with a temperature greater than 10 oC and lower than 15oC using gridcode but i can not seem to work out the ...
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1answer
36 views

Zonal Statistics with very large mosaic in ArcGIS

I have the complete National Elevation Dataset from USGS in over 3000 ArcGrid files (coming to almost 190 GB), and a polygon shapefile of Colorado counties. I'm trying to use ArcMap Zonal Statistics ...
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1answer
73 views

arcpy join csv files to raster attribute table

In arcpy, I'm trying to join an list of .csv files with data of emissions per country, with the attribute table of a raster in order to make lookup tables later on. So far this is my script: ...
0
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1answer
270 views

Creating an R factor raster in RUSLE Soil Loss equation with multiple input rasters

I am attempting to obtain the rainfall erosivity "R" factor for the RUSLE Soil Loss equation using rainfall PRISM 30 year history data. I have both monthly and annual data that comes into ArcMap as ...
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1answer
28 views

Does raster intersect polygon in ModelBuilder?

In ArcMap, I'm building a model which is iterating over ArcGrid rasters. I only want the steps to run where the raster intersects with a certain polygon. How do I add this condition to ModelBuilder?
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1answer
264 views

Exporting .tif from referenced mosaic dataset does not use functions in raster dataset

Very frustrating little issue in ArcGIS 10.1 -- I have a referenced mosaic dataset of terrain data that has a series of functions inserted (slope and several iterations of a statistics function to ...
3
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1answer
47 views

extract() function from r raster package returns different cells if “weights” parameter is TRUE or FALSE

I am trying to extract cell values from a RasterLayer based on a SpatialPolygons object. I create the raster with library(raster) rasterValues <- matrix(rnorm(20),4,5) r <- ...
2
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1answer
185 views

Why am I losing part of my raster when I reproject?

QGIS 2.0 Working with tiff raster file. Reprojections are in WGS84 Mercator. Here is my problem: I am trying to use buffers or urban areas to analyze light intensity on a raster layer. I want 30 ...
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1answer
36 views

Tin created from raster have different profile graphs?

I have created a TIN file from a Raster one, but the profile graph from TIN is different from the Raster. Here I attach a image where in the left is a profile graph from the raster, and on the right ...
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32 views

ArcGIS Pro 3D rasters?

I am trying to use ArcGIS Pro to create a 3D scene using an elevation surface (.tif) generated from drone imagery. The tif is projected and contains the elevation information, but I cannot get ArcGIS ...
0
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1answer
201 views

using raster.predict for Cubist model, factor levels list

I would like to thank in advance any help or advice. Let me know if I need to provide more reproducible data/code. I am working on a Cubist prediction model for soil texture, using continuous and ...
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1answer
30 views

How to get the pixels from a geotiff file in gdal python for a given polygon?

I use python and GDAL under apache to make a webservice. I have a GeoTIFF file and i want only a subset of the data, everything inside one polygon defined by a buffer of a line (coord is the input ...
0
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1answer
46 views

How to use ModelBuilder to run tool extract by mask on many rasters in ArcGIS for Desktop?

I'm trying to extract the same part of multiple rasters (Landsat scenes) using a polygon so I can do a time series. I've been trying to do it in ArcMap 10.2 ModelBuilder but the following error ...
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67 views

Why do I get “Insufficient memory for image” although there should be enough RAM?

QGIS reports "Insufficient memory for image 1403x716", when I want to load a raster. The problem begins after 1 hour of work. Had somebody had such problem? System win7 64 bit, 16GB RAM, Intel Core ...
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22 views

Repeatedly losing data sources for raster layers in ArcGIS for Desktop?

I have several raster layers that keep losing their data connection whenever I add a new layer from running a tool. I repaired the data source, but this keeps happening every time I run a tool. Is ...
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27 views

How to clip MrSID Files in R and export to GeoTiff?

I would like to use R to: Read in an MrSID raster (.sid format) Clip the extent using a shapefile Save the new clipped raster as a geotiff I am fine with steps #2 and 3, but I can't find any ...
4
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1answer
419 views

MapServer map file shows Raster image as white

I'm using PAN image for raster publishing but the output in browser shows a full white image? Please give me the solution? My map file is ass follows: MAP NAME "terra" # Map image size SIZE 600 600 ...
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1answer
166 views

IDW with QGIS from a vector points file within a mask

Given two inputs: A shapefile: points A raster: mask I want to interpolate the points within the extent of the raster except the NoData pixels that i want to use as a mask. NoData pixels are the ...
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2answers
122 views

Unstack band layers from raster

I have stacked layer (from ERDAS) of Landsat 1-5 and 7, bands. I want each of the bands in a separate layer. How can I do that?