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

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How to set the cell size of a tiff to 1 meter when working in a Geographic Coordinate System?

I am working in a Geographic coordinate system in ArcGIS, and I need to create TIFFs by exporting rasters. THese .TIF file must have a resolution (cell size, or GSD) of 1 m. Is it possible to set any ...
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3answers
913 views

Create a Raster file out of a ASCII grid file?

im using a special system to do geomagnetic surveys. Its software let me output the information as image files, ASCII or in its own proprietary file format. Now i want to get its information in my GIS ...
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1answer
110 views

qgis's georeferencer renders my white map with a translucent blue tint, can I prevent this?

I'm running QGIS 2.0.1-Dufour on MacOSX and when loading a PNG or TIFF into qgis as a raster its always getting rendered with a blue tint. Here's what it looks like before being loaded into QGis's ...
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0answers
361 views

Can hdf4 images be used in QGIS?

I'm trying to use hdf4 raster image in QGis 1.8. This image come from the MODIS satellite. I've loaded the file, it appears on the layer window bu it is impossible to see it on the display window. ...
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3answers
1k views

Is there a Raster Equivalent of the Split tool?

I have the DEM of a State in ERDAS Imagine (.img) format. I have a shapefile containing the counties of that state. I want to split the whole raster into DEMs of the individual counties. The counties ...
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108 views

Making grayscale map from multiple band satellite image in ArcGIS for Desktop?

I have satellite multiple band map, I needs to make grayscale map,what should i do? what is the steps? which band and format of input are to be used in this? How to make attribute table of this? In ...
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1answer
106 views

Error importing raster into GRASS plugin in QGIS

I am trying to import a tiff raster file into GRASS however every time I do this the below error message comes up. I am using a custom CRS so I have tried changing it back to the default CRS but still ...
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1answer
43 views

How to output the number of channels in a .JP2

I am looking for any tool (or python code snippet) that can loop through a file folder of .jp2 images and determine which have 3 bands and which have 4 bands. I am having trouble creating a raster ...
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3answers
456 views

How to combine raster and attribute table in QGIS?

I have some rasters representing string categorical variables. Each raster contains integers, used to translate the categorical variables. I have also the .csv tables giving the meanings of the ...
2
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1answer
267 views

ListRasters based on filename using Arcpy

I am trying to create a python script for ArcMap which calculates the ndvi from two raster images for each RGB/NIR pair in a folder. However, I am unsure how to create two raster lists; one which ...
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0answers
35 views

Interpolating points to surface not working

I am trying to create a surface from points using IDW interpolation. Have tried both 3D analyst and Spatial Analyst tool with my selected xyz data sheet. It appears to process and I don't get an error ...
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2answers
251 views

Changing raster resolution using ArcGIS for Desktop?

My raster is displaying at a very low resolution so it is almost useless. Last time I used this file it was at a much higher resolution, so I know the information is there. To change it I first ...
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1answer
67 views

Setting resolution for GRASS raster

I am trying to calculate volume using the GRASSplugin. I have my area information in vector format and my depth information in raster. I read that it is important to set the raster resolution before ...
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1answer
92 views

Batch processing of geodatabases - join raster with table

I am unsure how to go about doing this using Python in ArcMap, though I know how to do it by hand. I have geodatabases containing gSSURGO data, one for each state, in their own folders. I have a ...
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1answer
41 views

Split linear features from non-linear in the same feature class

I have a vector layer (Originally a raster layer) of well sites, cut blocks, and seismic lines all lumped together in the same feature class and no distinguishing attribute between them. I want to ...
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1answer
398 views

Determining the slope of a DEM (SRTM-data) in QGIS

I'm new to QGIS and I have to calculate the slope of a DEM (I use srtm-data). I already detected the geoalgorithms toolbox and I also produced a raster layer with the slope using the tool "slope, ...
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1answer
187 views

Disable black background color of a satellite image in mapserver mapfile?

I'm publishing rasters using Mapserver. How to disable background color of a satellite image in map files or How to set “Display Background value ”0“?
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3answers
1k views

Per-pixel (statistical) calculations on a raster stack using GDAL

In R, it's relatively trivial to perform per pixel calculations based on a raster stack (e.g., get std.dev for each pixel on a 12 layer GeoTIFF). Unfortunately, the speed is less than desirable when ...
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1answer
166 views

Making color map in ArcGIS for Desktop?

I have bands 2, 3, 4, and 5 map. How can I use these to make a color map in ArcGIS 10.1 for Desktop? Can you give me steps? Also I want to make attribute table of colormap. How this can be ...
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1answer
133 views

Difference between source SRS and target SRS in Raster Warp function

Hello I am trying to change a raster layer projections from WGS84 to a custom Lambert layer using 'Raster' --> 'Projections' --> 'Warp' function. I have been asked for source SRS and get SRS. what is ...
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3answers
438 views

LiDAR data density, returns per square meter

How can I compute a raster showing the number of return points per square meter using SAGA GIS or other open source software? My goal is to obtain a mask which would show me the places (cells) ...
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1answer
1k views

Counting NoData values in raster using ArcGIS Desktop?

I have created a raster in ArcGIS Desktop 10 with a large number of holes (NoData) in it. I want to fill the holes using something like the the following: rOut = ...
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2answers
1k views

Calculating Net Primary Production (NPP)?

When I calculate Net primary production (NPP) for a local scale, what kind of software should I use? I always use ENVI, ERDAS IMAGINE, ArcGIS for Desktop and IDRISI. Is it possible to use these ...
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1answer
941 views

Combining two overlapping rasters (combine cells, retain both values) using ArcGIS for Desktop?

Using ArcGIS 10.2, I am trying to combine two rasters which are identically overlapping in shape and extent, but with different values and counts. As an end result I would like each cell to retain ...
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1answer
126 views

How to digitize RGB TIFF automatically

Is it possible to digitize RGB TIFF by color - I need to select all the vegetation cover types from the image below, which is a part of an aerial photography of an island ...
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274 views

Problem loading output layer QGIS

Every time I run operations with temporary file output from the graphical modeler, I get the following error message: Oooops! The following output layers could not be open CLIP: ...
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1answer
245 views

How to convert float to raster in QGIS

I have downloaded bathymetric data into QGIS. In order to use it I need to conduct a float to raster conversion. I have not been able to find how to do this on any of the forums. I have unsuccessfully ...
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0answers
89 views

Error on 'Extract raster values to CSV' in batch process in QGIS

The Extract values (csv) contained a bug in the script. The below link shows how to correct the bug. Error on 'Extract raster values (CSV)' - Error executing algorithm 1 'Dataset' ...
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2answers
259 views

Resolution difficulties in Grass

I have gone through similar questions to mine here, but I didn't find a solution. Please help! When cropping a raster image by using g.region & r.mapcalc, I get a new image but the resulting ...
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1answer
208 views

Why covariance values are different in R and ArcGIS?

I've calculated covariance between 7 rasters using R and ArcGIS. It gives me different results. Each times covariance values from R are approximately 1.874 times higher than ArcGIS values. R - ...
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57 views

What kind of methods are most commonly used to interpolate a relief?

I have got a topographic plan with height measurements which I converted to point shape file with height value in attributes. I was wondering, what kind of methods are most commonly used to ...
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1answer
572 views

How can I transform raster to vector in ArcGIS?

I want to convert from raster data to vector dataset using ArcGIS. Raster data consists of pixels and center of z values. Vector data sets consist of points, lines and polygons and x,y values. When I ...
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1answer
63 views

European road usage statistics per highway

I'm looking for an open data source which features the amount of cars per road per day or per year for Europe(!). I've found several national reports, which are only available as PDF and as such a not ...
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1answer
983 views

How to extract pixel value counts from a raster in QGIS?

How does one go about obtaining a summary of the counts of cell values within a raster in QGIS? I know QGIS is doing this, in order to provide the summary statistics and histogram in the properties of ...
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1answer
92 views

Error on 'Extract raster values (CSV)' - Error executing algorithm 1 'Dataset' object has no attribute 'mapToPixel' See log for more details

I would like to extract raster values at some locations (point shapefile) in 'csv' format. I use 'Point Sampling Tool' and it works well for a raster file. However, I have hundred of raster files ...
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1answer
215 views

Progress bar percentage is increasing and decreasing, never finishing

I am trying to clip a raster by shapefile perimeter using the Clip tool. The percentage has been jumping between 0% and 100% for over an hour, back and forth, climbing to 100% then dropping down to ...
5
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1answer
589 views

Creating field with specified slope projecting from 3D polygon?

I am trying to figure out how to create a elevation raster from a known location (3D polygon) that projects at a specified slope (1%) for a specified distance(1-2 km). Does anyone have any idea how ...
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1answer
235 views

Adding a grid and selecting random cells from spatial polygon in r

I have a fairly similar question to this: Similar Question I am working with a map of Denmark or more a subset of a Denmark Map. This file comes from the Global administrative areas site GADM site ...
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2answers
44 views

Get raster expression

In Arcmap I have made a new raster with ArcToolBox -> Spatial Analyst Tools -> Map Algebra -> raster calculator. Now, months later, I have forgotten the source formula expression. How can I ...
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1answer
53 views

Combining raster images? [closed]

I've decided to work on GIS implementation in transportation. I've these small tiles of images, with world files. I want to combine them to create a base map. I don't know coding/programming, so ...
3
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2answers
476 views

Cropping or removing borders (not NoData) from multiple scanned and georeferenced maps (ArcMap or QGIS)

I have several hundred scanned maps in TIFF format, each correctly georeferenced and forming a large grid of images. The problem is that the border for each map is present - a white band, with a black ...
3
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1answer
690 views

Problem about converting raster to polyline and calculating total length

I have raster file of line segment. I need to convert it to line and get the distance of that line. How can i do using Python and ArcGIS 10? I have tried with GIS tools Convert Raster to Polyline but ...
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1answer
559 views

How to create the attribute table for a raster that was produced by the Slope Tool (ArcGIS10)?

I use the Slope Tool (Spatial Analyst Tool – Surface) of ArcGIS10 by ASTER GDEM (that was exported to UTM projection). The program produce new raster (with slope value), but the resulting raster ...
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1answer
85 views

Converting rasters to polygons through cell centers

With arcgis, it is possible to convert a raster image to a polygon representing the boundary of the raster using the Raster To Polygon tool. The output polygon will follow the cell edges of the ...
2
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1answer
132 views

Export raster from QGIS 2.4 to PostGIS

How can I export a raster file out of QGIS (version 2.4) into a PostGIS database? I am looking for a module or python script.
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1answer
61 views

DEM error when trying to do topographic correction in GRASS

I'm new to GRASS gis and I'm trying to do a topographic correction (i.topo.corr) of 9 ASTER bands using SRTM dem. I keep getting this error message: ERROR: Illumination model is of CELL type Is ...
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205 views

How to correctly render a raster Layer to GTiFF with QGIS python console?

I am trying to render a map from a raster layer. As recommended in pyqgis cookbook and here(osgeo.org) I use QgsMapRenderer(). I am able to produce a picture but it has not appropriate extent and ...
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0answers
141 views

Changing extent on a raster in QGIS

I rasterized a shape. The resulting raster (lets call it raster 1) has a different extent. I made a virtual raster with the original polygon and I tried to multiply the virtual raster with raster 1 ...
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1answer
211 views

QGIS Scripting problem updating contrast enhancements for raster layers using bandStatistics

Found this function to update statistics for a raster layer : rlayer.setContrastEnhancement(QgsContrastEnhancement.StretchToMinimumMaximum, ...
3
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1answer
103 views

Underwater terrain modeling

My task is to model the surface of a lake bed, calculate volume of it and visualize it as 3D a surface. I have acquired depth measurements in a small lake using echosounder. The precision should be ...