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

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2answers
3k views

Iterate through multiple Raster files and compute statistics using Zonal Statistics

I have a large number of raster images. What I'd like to do is to compute statistics on different sections of these raster files using a polygon. I think everyone is suggesting Zonal statistics. ...
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0answers
110 views

Color blending/compositing in web mapping frameworks?

The color/layer blending capabilities of QGIS 2 produce marvelous results. Blended rasters are especially nice to look at. Blending is, to me at least, a better way of combining layers than mucking ...
1
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3answers
767 views

Cache generation failed. Progress gets stuck at 0%

I'm trying to publish a map service containing a large .tif raster (48GB). I managed to publish a small cached raster successfully (for testing), but when I tried to publish the large one, the cache ...
2
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1answer
428 views

Wrong values in Feature/Point to Raster

I've got an XY dataset that I'd like to convert to a raster, based on the ETrel_whol field. The ETrel_whole field includes NaNs and ranges from 0-1. I would like to convert this to a raster, with a ...
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1answer
139 views

How to build and pass remap for floating point raster without getting Reclassify ERROR 010255?

I am receiving the following message when executing my python script: ERROR 010255: String remap must be used with a string field. My input raster is floating point and I would like to ...
2
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1answer
135 views

How do I create smaller maps for publishing from multiple tiles representing a large map using QGIS?

I am completely new to cartography and QGIS - I'm a writer, editor and acceptable designer (Adobe Creative Suite). I wish to produce PDF tour guides featuring maps that display a route. One version ...
7
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3answers
2k views

Merging hundreds of Aerial Photos into one big file?

I have tried to merge my 405 Aerial Photos into one. I have FME and ArcInfo 10.0 at my disposal on Windows 7 64bit. I have tried the following: create a mosaic; export all images from a ...
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0answers
52 views

Warping Rasters in QGIS

There seems to be a bug warping rasters in the new QGIS version 2.0 When you have to option of target and Source SRS, the Coordinate reference system does not get automatically writen into the box ...
2
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1answer
405 views

Tabulate Area for large datasets

I have been struggling trying to use Tabulate Area in Arc 9.3 for a large raster dataset. I have one raster with 8 land uses and another vector layer with zones (which I converted to a raster with ...
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0answers
148 views

Mann-Whitney U test for rasters

I'm doing a Mann-Whitney U test to compare two very large samples (sample size 1 = 13250; samlple size 2 = 38871) originating from a shapefile with 52121 features. I know t-tests are not recommended ...
4
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2answers
2k views

Efficient way to handle NA values from analysis in R with Raster

I am not 100% sure if GIS is the correct stackexchange for this, but here we go. A problem I have been bested by: I have a raster layer of approximately 240 million cells. It could be a DEM or ...
3
votes
1answer
2k views

Service published but cache generation failed on ArcGIS Server

I am trying to publish a map service containing a cached raster layer on our ArcGIS Server Enterpise 10.1. I analyze the map service before publishing and no error. The error I get when publishing ...
2
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1answer
104 views

resampled thematic map accuracy

I've generated a map of ecoregions based on some environmental data using a semi-supervised classification where I combined a statistical clustering with random forests to generate my map. I created ...
6
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2answers
770 views

How to de-noise a DSM

I have created a DEM, DSM, and nDSM from a LiDAR Point Cloud using SAGA-GIS. I extracted the appropriate returns from the point cloud, then converted to grid, and then closed gaps to fill in any ...
4
votes
2answers
239 views

Problem overlapping shapefile and vector in R

I want to plot a shapefile over a raster file in R but I can't make them overlap perfectly: the raster appears to be rotated of few degrees counter-clockwise. Is it a problem with the projection? ...
3
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0answers
170 views

Calculate surface elevation from DEM of pit and known volume with which it is being filled

I am using ArcGIS 10.1. I have a DEM of a pit. I have a known volume of material that I want to put in the pit. I want to know what the elevation of the flat surface of this material will be ...
2
votes
1answer
400 views

Does ModelBuilder need to use variable to define projection and then re-project?

I am trying to build a Model in ModelBuilder to create two different process raster datasets: One set is to define a raster dataset to set a WGS 84 projection; and then the second set is to take ...
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1answer
3k views

How to Build Raster Attribute Table from .tif with pixel type of float or double?

I have a raster with the extension .tif. It's a subset of 87x87 pixel with values from some 6,66 to -4,27. If I right click on it there is no Attribute Table available. However, I can change the ...
4
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1answer
472 views

How to create Series of Rasters that displays Standard Deviation from Mean?

Cell statistics question for you. I have 100 rasters of raw rainfall data in which the pixels each represent rainfall for that particular pixel on the landscape for a single year during the 100 year ...
2
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5answers
2k views

How to export raster from PostGIS enabled DB as GTiff with gdal_translate

When I want to export a GTiff from my PostGIS DB with this code: gdal_translate -of GTiff PG":host='localhost' port:'5432' dbname='landslide' user='postgres' password='pass' schema='public' ...
2
votes
1answer
105 views

Raster clipping over 1300 km2 orthophotos

I have all of Denmark in 25 cm orthophotos added to my ArcMap (mosaic dataset). I've added a polygon of an area covering over 1300 km2. I've used the raster clip tool to clip the data into a new ...
2
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0answers
256 views

How to write script for Line of sight and Viewshed analysis in Global Mapper

I wanted to write script in Global Mapper for Line of Sight and Viewshed analysis. I tried to calculate using Viewshed and Global Mapper Tools but the issue I am facing is that analysis is user ...
5
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1answer
1k views

GDAL polygonize lines

I have a raster file containing roads (left image). I polygonize the raster file with GDAL (see the script below). In the end I like to have vector lines. However GDAL only gives me something like ...
2
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1answer
726 views

GDAL polygonize only certain raster values

I want to polygonize a raster file with GDAL. I only want to rasterize cells with a value of 0. Is it possible to specify that within the polygonize function or do I have to modify my raster before ...
5
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1answer
752 views

Generate hillshading with GDAL, and respect nodata

I'm still trying to nut out this problem of merging overlapping geotiffs. From the original dataset (here, a 20m resolution digital elevation model of the state of Victoria), I have reprojected it ...
2
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3answers
1k views

how to decrease Raster size without altering cell size?

Is there a way to decrease the size of a raster image without decreasing cell size or quality? I´m using ArcInfo but also have Saga-Gis or FME. I could abviously change an 8bit raster to a 1bit ...
2
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1answer
3k views

How to create attribute table for raster data?

I have raster dataset for rainfall but its not having attribute table. How can I create tabular data using the same raster file? How to join it back again to it? Software used is ArcMap 10.1.
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1answer
240 views

Arcpy.GetRasterProperties_management values do not match values found via ArcCatalog or ArcView

I am using Arcpy to extract the mean and standard deviation values of tiff Landsat satellite images and I get very high values. Values in the thousands rather than in the low hundreds! If I look at ...
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0answers
203 views

How to Iterate ModelBuilder for Zonal Statistics?

I want to use ModelBuilder to split a DEM into multiple tiles, then run the iterator on each tile made for the Zonal Statistics tool to find the highest point(s) in each tile and give these as an ...
0
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3answers
318 views

Grouping Multiple Raster Layers

My question is how to create multiple raster layers group, for example when using several aerial photos. I wish to group the layers into one so that I can edit/select as a batch rather than having to ...
0
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1answer
75 views

ArcGIS10 Highest point via polygon features

I am using ArcGIS 10.0 with 3D Analyst, Spatial Analyst and Military Analyst. I feel like I am halfway to solving a problem but do not seem able to completely solve it. I have a polygon shapefile ...
2
votes
1answer
509 views

Convert multiple Shapefiles in Raster in R(and then plot it)

I'm trying to convert several shapefiles in rasters at the same time. I already was able to read the shapefiles by doing this: library(maptools) shps <- dir(getwd(), "*.shp") for (shp in shps) ...
3
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1answer
476 views

How to reclassify a raster (tiff) with multiple bands?

i have a raster file containing information about the windspeed average for the year. My purpose is to reclassify the 15 classes based on their rgb-composite. The color is the only information given. ...
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1answer
645 views

ArcMap Raster to NetCDF - lat/long

I need to convert a few files which are projected in WGS84 into netCDF. NetCDF requires lat/long. I am a bit confused on how the process is handled by ArcMap especially after looking at the online ...
1
vote
1answer
358 views

Why does georeferencing reduce the image resultion?

I'm trying to use a raster as a base image in my QGIS project. It is a building schematic which is fairly high resolution. Importing this into QGIS, it seems that the only way to re-position an ...
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1answer
61 views

Needed a free high resolution imagery for Las Cruces, New Mexico area

I'm Looking for a free download Imagery that is a very high resolution and the most recently like the past 3 months. I'm doing to produce a map where our new building being move into next year ? Is ...
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0answers
239 views

Why are the colors of my WMS layer messed up in QGIS?

I have a raster image on my computer, and I used it to test some geoserver features. (I'll upload images to show you what the problem looks like) I have the same raster, but transferred by wms. And ...
2
votes
2answers
1k views

Most efficient option to create a raster basemap for a web application?

I'm sure this is probably a common problem and many have already found the right answer. I have a large mosaic raster file (a city's ortophoto) in .ecw fromat and we want to use it as a basemap in a ...
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0answers
408 views

How to convert Raster to points in MapInfo?

I wanted to convert Raster data to point data in MapInfo.Does there any tool to convert? can anyone help me?
1
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1answer
91 views

Raster Data to Polygon [closed]

I need to "translate" raster information to a set of polygons. The raster to polygon tool will not work. I created a fishnet with the same resolution of the raster and converted it to polygons. I now ...
7
votes
4answers
4k views

How to convert raster to point in QGIS

I wanted to convert Raster into Point Vector in QGIS. Is it possible? QGIS have option to convert it into polygon but i didn't found any tool to convert it into point. can anyone help me?
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0answers
96 views

How to Clip a Raster dataset so that it is smooth along a boundary [closed]

I know how to clip a raster, however I need it to be smooth along the edge of a boundary and not jagged as can be seen in the image.
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0answers
87 views

Interpolation Technique

We have following solar metro logy parameter through satellite data with resolution of 100 Km^2 (10Kmx10Km) Insolation on horizontal surface Diffuse radiation on horizontal surface ...
2
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2answers
1k views

Spatial Analysis - Calculate a cells elevation (height) above the nearest stream cell

I have searched for some ideas on how to formulate this analysis, but have come up short. I imagine there is a pretty straight forward answer; any help would be greatly appreciates. Data: DEM, ...
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0answers
36 views

Map algebra from QGIS python console? [duplicate]

What command do I use to do map algebra on rasters from the QGIS python console?
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1answer
42 views

Georeferenced labeling

I have a problem with ArcMap that somehow affect georeferencing. So I have three layers, two with .lyr and one is a raster data. The two .lyr datatypes are a border and cities with names. I ...
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0answers
63 views

What type of calculations must be done for traffic emission for buffers in land use regression?

I have a raster layer that shows traffic emission distribution by kernel density method. Traffic emission will be used as independent variable in land use regression. What type of calculations must ...
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1answer
366 views

If road lengths are raster layer, how to calculate road lengths for different buffers?

A question related calculation of road layer lengths using raster layer for land use regression. If raster layers are used instead of vector layer for calculation of land use area and road lengths, ...
4
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3answers
2k views

How to change layer transparency without changing border lines?

I have a raster image of elevations. I have added a vector shapefile that contains local political divisions. I want to keep the elevation colors, but I want to keep the black lines representing the ...
1
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1answer
118 views

Viewshed calculation using SQL

Can i calculate viewshed in MS-SQL server? Viewshed analysis is Raster operation. I have elevation value vector observation as point vectors. Are there any methods to calculate Viewshed (using ...