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

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How to reclassify a float raster?

I have three rasters which represent distance (in metres) from certain things (bus stops, parks, libraries). I would like to reclassify these rasters so that they get integer values based on the ...
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43 views

simple raster format to use in Web applications?

I'm building a Web application in which users create and edit very coarse raster data. They're assigning values to cells in a georeferenced grid. Right now I'm storing the values in a multidimensional ...
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1answer
11 views

Rasters change pixel size and range of values when imported into QGIS

I have observed that when I import rasters into QGIS their pixel size changes and also, the full range of the raster's value does not appear. For instance, I may have a raster with values ranging from ...
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3answers
27 views

Save rasters created by loop operation to different directory?

I have a set of rasters. I crop them all using FOR loop. Then, I want to save new-created rasters in new directory, not in my actual directory. For one raster it is easy: writeRaster(raster1, ...
2
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1answer
19 views

Error converting a raster to polygons

When I am converting a raster using the polygonize tool, I get this error: ERROR 4: 'C:/Users/Vitor/Desktop/Cartografia EE_Portimo/COS RASTER/cos_raster_reeditada.tif' does not exist in the file ...
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1answer
251 views

Building attribute table from raster in ArcMap 10.1

I have a NetCDF file containing the latitude, longitude and porosity for the entire US. I am trying to add another value (wilting point) which depends on the porosity. I wanted to extract the netcdf ...
3
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1answer
472 views

Why is Orthorectify button not active in Image Analysis Windows in ArcGIS10?

I wanted to Ortho rectify GeoEye HR imagery using existing RPC and IFSAR DTM in Image Analysis. According to ArcGIS Resource center ...
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3answers
25 views

Mapinfo : How to cut a raster with a vector layer?

With mapinfo 12, i would like cut my raster layer .tab with one of my vector layer. How to do this basic task with mapinfo? Is it possible with mapinfo to convert .tab raster table toward any ...
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1answer
28 views

Got different cell sizes from a rasterised data

I'm trying to rasterize the Land cover data of Nigeria which was obtained from FAO database. During the process of rasterizing the land cover data, I used the following information which gave ...
2
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2answers
28 views

Python Script tools for ArcGIS 10.2 is very slow (get raster properties)

I am using python script tools for ArcGIS 10.2, under Windows 8.1 64bit. When I am using the arcpy.GetRasterProperties_management() command, it's very slow to process the data. For example. I tried ...
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0answers
7 views

How to calculate interval areas in raster?

I would like to know if is possible and how can i calculate the areas from class intervals in one raster? All help is appreciated, Best regards
2
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1answer
26 views

Overlaying two raster images with no spatial reference

I have two images (X-Ray and Neutron Tomography Scan) of a human bone fragment. I want to use ArcGIS 10.2 to accurately overlay (geo-reference) these two images which have no spatial coordinates. any ...
0
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1answer
11 views

Raster2pgsql overview method

What is the method used by Raster2pgsql to create overview? I couldn't find details in the docs. Nearest neighbor isn't a very good choice for the dataset I'm working on, but that seem to be the one ...
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2answers
119 views
+50

Creating spatial Reference to ASCII file

I have produced ASCII files in MaxEnt. These files are able to be loaded into Arcmap10.1 and display as an image, but I cannot interpret them or create them into a polygon for further analysis. I have ...
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2answers
31 views

Arc - how do I find the coordinates of the centroid of a raster?

How do I find the coordinates of the centre / centroid of a raster? I have tried Zonal Geometry but this does not give me the coordinates. I need to find the centroids of two rasters and create ...
3
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2answers
405 views

Rotating rasters using GDAL Geotransform (and ArcGIS Desktop)

I am working on a GDAL driver for a proprietary grid-format. In some cases, the grids are rotated in order to get smaller file sizes. In my GDAL geotransform array, I do the following (showing a ...
0
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1answer
1k views

How to convert a bil image into grid in ArcGIS?

I've downloaded RFE data from FEWSNET. It's a compressed file which includes .bil files. Now i want to convert this ".bil image" into a grid to use the precipitation data in an area. I'm using ...
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1answer
10 views

Open and split a 4 channel RGB picture

How can I split an 4 channel rgb pic in qgis? With the value tool I can see 4 channel. I tried to use the RGB to PCT tool but I always get an error (File "C:\PROGRA~1\QGISBR~1\bin\pct2rgb.py", line ...
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1answer
125 views

Rotating raster grids using ArcObjects changes cell size in ArcGIS Desktop?

I am using ArcObjects, namely RasterGeometryProc, to apply rotation on grids. The transformation works fine. However, when looking at the grids properties in ArcGis, the cell sizes has changed. ...
3
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2answers
685 views

Majority filter (minimum mapping unit) in ArcGIS Desktop with larger window size?

I want to run the majority filter in ArcGIS Desktop with a window size of 4 or 5 i.e. greater than the default 3. Is it possible, or is there some other command (or tool) which might help me achieve ...
5
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1answer
103 views

Is there limit of 5,000 rasters stored in folder by ArcGIS for Desktop?

I have a python script that creates batches of ~6,000 cost distance rasters. These rasters are intermediate data that will be summarized in another process. Output is stored in plain old folders. ...
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1answer
77 views

Which kind of grid format is this?

in a project I got some raster files with the following content (header and data are in one txt file): HOUR 17 MINUTES 30 YEAR 2012 MONTH 5 DAY 4 CITY Emilia;Bologna NROWS 99 NCOLS 156 ULXMAP ...
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41 views

Arcpy script for summing pixel values in loop can't handle large number of rasters

I want to sum the pixel values of large numbers of rasters of different extents (ArcMap v10.2). 16GB RAM. I have the following code (with help from this site) which solves the different extent ...
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0answers
8 views

Transparency on black/white raster after clipping in QGIS?

I'm new to this forum and QGIS. I'ld really appreciate it if you could help me with my problem, since I couldn't find any solution online but people experiencing the same issue. It seems as if this ...
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3answers
24 views

Raster algebra to tiled maps on a sever with open source solutions

Let's say I have a collection of data in raster format. It changes daily. Once each day I would like to do some fairly complex raster algebra on these datasets. I would like to be able to do the ...
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2answers
190 views

How do I properly save/export a raster in QGIS? [on hold]

I am trying to save edits to a raster file in QGIS, but; When you edit a raster file and select "Save As"; no output file is generated. My version is in Spanish; however "Save as raster layer" is ...
8
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1answer
547 views

How to view a 155 MB raster stored in PostGIS?

I am using the following command to load a raster into a postgres database: raster2pgsql -I -C -e -Y -F -s 3086 -I -C -M myraster.tif myraster -F -t 30x30 | psql -U postgres -d database -h localhost ...
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5answers
3k views

Problems merging DEMs or other raster datasets? Clipping Raster dataset to vector line?

I have two DEMs that I am going create a hillshade from, and ultimately want one hillshade clipped to a county boundary. I am running into a couple problems, though. When I try to merge the two ...
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14 views

Slope tool output has artifacts

So I've tried using the slope tool for a DEM using an appropriate Z-factor and the output is smooth, but it seems to be over-estimating slope angle. I would prefer to reproject the DEM (to NAD 83 UTM ...
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0answers
9 views

Mosaic to New Raster not allowing correct overlap

I am not sure what exactly is causing hiccups for me - how I processed the data (removing the white edges in 3rd party software), the bit depth (8bit), the file format (png to support transparency), ...
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2answers
83 views

How to subtract rasters using the gdal_calculate command

I just want to know how to subtract two raster using gdal_calculate command? Or what is the proper way of subtracting using this? Any idea would be greatly appreciated. Note: gdal_calc is different ...
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3answers
64 views

Mosaic to New Raster tool fail

I'm trying to merge 24 DEM files, after applying the tool (Mosaic to New Raster) only 11 out of the 24 merged. All the original files are in the same projection, pixel type, band, etc. I also ...
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3answers
36 views

Raster calculator to create single raster with 4 values from two binary rasters

I have two binary rasters showing habitat suitability (0 = unsuitable, 1 = suitable) under current and future climate scenarios. I am trying to create a raster showing: 0 = cells that are not ...
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30 views

Reprojecting a population raster from LAEA to lonlat

I have a population density raster from the EEA which is based on the CORINE land cover 2000 data. ...
1
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1answer
44 views

Load the raster image which is in TIF format using QGIS API

I am quite new inthe field of GIS. I am interested in is to load the raster image which is in TIF format using QGIS API I have followed the steps given the in the follwing link to load shape file ...
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123 views

Interpolating shapefile of points to grid using Java?

I am looking for a method/prog/library(java) to interpolate points from a shapefile to a grid (file). I have seen arcgis can do that but i am looking for something free. More specific: i have ...
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2answers
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How to make RASTER from irregular point data without interpolation

I was trying to make a raster image from an irregularly spaced point database. The data looks like- > head(s100_ras) x y z 1 267573.9 2633781 213.29545 2 262224.4 2633781 ...
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1answer
160 views

Convert a KML ImageOverlay to World Files with GDAL

I have many raster outputs from an Open Source radio transmission topographic path tool called SPLAT, georeferenced in KML image overlay format. I have figured out an easy way to use tools to ...
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12 views

How to get background maps to show in QGIS Cloud mobile version?

we're a group in Denmark, trying to publish some maps for use on a mobile device, but although our background maps show up in the desktop version, we can't get the mobile version to show them - What ...
7
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1answer
108 views

Methodology for Hansen classification of Global Forest Watch?

I have just discovered amazing Hansen´s classification about forest loss and re-growth, available at http://www.globalforestwatch.org/, published in Science, 2013 as: Hansen, M. C., Potapov, P. V, ...
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1answer
150 views

Convert point to grid: Numbers of cells differ

In R I am trying to aggregate points data to a grid. The data for the grid (G-Econ) comes as a csv-file. In this file each row represent a grid-cell at 1x1 degree resolution and the given ...
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1answer
129 views

How to create a raster with rotated cell orientation from lattice points - ArcMap 10.1

I am trying to create a raster layer from gridded points where the cells have a rotated orientation. Each point is the center of a 1.6 km by 1.6 km cell, rotated to the left. Is there a way to do this ...
4
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3answers
2k views

How can I specify the CRS of a raster layer in pyqgis?

I manipulating netcdf raster data from the QGIS python console. The metadata of my netcdf file does not provide the Reference system. However I know it is 'EPSG:4326' I am writing a python script to ...
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2answers
32 views

Equivalent to Sieve tool in R {raster}?

I would like to remove isolated pixels (or clumps of pixels <9) from my raster image. library(raster) # create some raster data r <- raster(ncols=12, nrows=12) set.seed(0) r[] <- ...
2
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1answer
155 views

How to view a raster in CartoDB?

What is the easiest way to view a raster in CartoDB? From the list of formats that you can upload into CartoDB, I noticed that .tif is available, so I've tried adding a GeoTIFF, but it says that ...
2
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3answers
37 views

Raster symbolization in open source web gis

We would like to build a simple web map application that displays raster data (e.g. a digital surface model) and symbolizes values (e.g. height) using a color ramp. Is it possible to have the user ...
5
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1answer
408 views

Raster vs Grid vs Lattice terminology?

I have a question about GIS terminology - what is the difference between grid and raster and grid and lattice - in theory?? I thought, that raster is regular network and value is in the cell and the ...
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0answers
17 views

Isolation and interpretation of vineyard multispectral data

I have 3 band multispectral raster imagery over a vineyard from which i have created a number of indices e.g. NDVI. The data is fairly high resolution (5cm/pixel) so shows a lot of along vine and ...
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2answers
21 views

Getting raster values on grid nodes

I have my raster layers of Digital Elevation Model, aspect, slope and curvature for a certain region. In this region I want to apply a grid with a certain spacing in its nodes, and then get the ...
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2answers
122 views

gdal_grid has some problem with reading vrt file

I am using gdal_grid module(from gdal 1.10) and it has some problem with reading the vrt file. I checked this link but it does not work. gdal_grid problem reading vrt file The command is ...