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

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How should i combine these rasters?

I have two buffers that i want to combine. I tried overlay with fun=function(x,y){return(x*y)} but 0*5 = 0 so it produces NA's.I don't know how to combine them the one buffer should be 500 and the ...
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19 views

Reclass by Table giving output with only 8 catergories

I am attempting to reclass a raster from a table (using the Reclass by Table tool in Arc 10.3). The output value field I am trying to reclassify to is long integer format with values ranging from 0 ...
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14 views

What is the recommended approach to client side clipping, by geometry, of an ArcGISImageServiceLayer?

I have an existing Esri Silverlight application with an ArcGISImageServiceLayer and we need to add the ability to clip that raster, by a geometry. And ideally, do this on the client side since the end ...
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2answers
46 views

Editing .tiff rasters in Python

I am triying to edit .tif rasters in python, but I have some issues regarding the tiff to array converstion. I read there are multiple options for opening rasters (gdal, PIL, matplotlib), but which ...
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2answers
48 views

How to sum pixel values of a floating point raster in ArcMap?

I have a floating point raster with values from 60 up to 95 (with decimals), it has 7077 pixels of 250x250m size. Is there a way to sum all pixel values of this raster? For example, if the raster had ...
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1answer
62 views

How to reclassify a raster in R?

wet<-readOGR(dsn=".",layer="shp") #wetlands r.raster <- raster() extent(r.raster) <- extent(wet) res(r.raster) <- 100 wet.r <- rasterize(wet,r.raster) #rasterize plot(wet.r) ...
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3answers
61 views

Combining rasters to calculate total inputs

I am working on creating a map of total chemical inputs into a study area. I have several raster layers of different inputs with values stored in the attribute tables. I am having a hard time ...
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1answer
68 views

Split raster into tiles

I have a raster that needs to be split into tiles (each tile a new raster). I have a Shape file with multiple polygons (these polygons are how I want the raster split). I have Gdal and QGIS. Any ...
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1answer
36 views

how can I get the majority (dominant) class of a raster to an area (polygon) using qgis?

I have a vector layer with many basic units of planning (zones), a raster layer with three classes of geology and other raster layer of geomorphology with five classes. How can I update the ...
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32 views

Combining tiff with shapefile

I have a geotiff image with a D_WGS_1984 Datum of land cover for the continental US and I want to be able to merge it with a US counties shapefile. What is the fasters and best way to do this? My ...
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1answer
86 views

How to reproject a raster from lat/lon to UTM in R?

i have to turn it into a UTM in order to make the buffer functional. wets<-readOGR(dsn=".",layer="shapefile") r.raster <- raster() extent(r.raster) <- extent(wets) res(r.raster) <- 100 ...
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54 views

Raster map source for desktop, commercial application

We develop desktop, commercial application for Architects (c++). In a future update, we would like to provide our customers with the option to automatically create a 3D terrain with appropriate ...
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1answer
53 views

How to rasterize a vector dataset in R?

I would like to compare vector vs raster data. So i try to fix a problem using both ways. I made it in vector first : coastline<-readShapeSpatial("shp") wets<-readShapeSpatial("shp") ...
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33 views

Problem with calculating slope in QGIS

Ive downloaded DEM form earthexplorer. But after calculating slope I only have blac img. with same value in min. and max. When calculating aspect or relief, DEM works correctly. Have you met with ...
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17 views

Replacing white or black by alpha channel in raster in QGIS 2.8

I'd like to replace black or white in black and white raster in QGIS 2.8. I perceived that in some other raster where "nan" value automatically occurred and only white or black is being displayed.
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42 views

calculate Z~F from polygon and raster

I have a polygon shapefile and raster layer. How I can calculate the elevation and area (Z~F) relationship for each polygon by using QGIS or ArcMap?
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1answer
189 views

Create raster with grid cells values based on area covered by polygons

I have a polygon data with area covered by the forests (data is here - https://www.dropbox.com/s/zgckliydalljw6a/sp_data.zip?dl=0). I want to convert polygons to raster. The value of each grid cell ...
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2answers
96 views

Dissolving/Unifying Ill Behaved/Irregular Polygons in R

I'm working on a project involving bringing together multiple subjects circling difficult to find parts of an image. The output from users is pretty awesome. Cool, right? However, what I want is ...
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1answer
111 views

Raster to vector (polygons) with generalisation

I have created rasters showing different types of vegetation (bushes, trees, open land) with help from lidar data. Now I'm looking for a method to turn these images into polygons. I'm using a Mac ...
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38 views

Converting a (WAsP) vector map to a raster map with GRASS GIS

i'm quite new to GIS and i need to convert roughness data which is available in a vector format to a raster format. The final data should be on a simple 2-dimensional uniform grid with a constant grid ...
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18 views

“Mosaic to new Raster” just stop working

I have been using the command "Mosaic to new raster" so far successfully. Now, without changing any option from before, it just doesn't work anymore. It is something it already did: pretending to ...
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28 views

Raster NoData Issue

I have three landCover maps (2000,2006 and 2012),I am using ArcGIS 10.1, I converted them into raster (from polygon to raster 100x100 cell size), I guess because it is remote sensing maps (obtained ...
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1answer
20 views

How to get the upstream average of a raster data layer that falls into a river network?

I have a raster layer of a network of rivers and a raster layer of data I want to extract. For each pixel of the rivers, I need to know the upstream average of the data layer that falls into the ...
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1answer
31 views

zonal statistics sum on raster with same values

I was wondering if anyone knows what exactly zonal statistics sum does if all my input value raster have the same values. For e.g. Lets say I have a finer resolution raster with 10 pixel each having ...
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47 views

PostGIS: intersection of a polygon with 2 rasters

I'm trying to get the intersection of a Polygon with 2 raster layers in PostGIS. The rasters have the same size and pixel size and I'd like to retrieve for the polygon a list of something like that: ...
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3answers
41 views

Selecting parcels in vector map from raster layer using ArcGIS for Desktop?

I am relatively new to Arcgis and I am stuck. I have a parcel map (vector) and a land cover map(raster). My land cover map is only 1's and 0's, flood and no flood. I want to be able to highlight or ...
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1answer
12 views

error 00289 while projecting raster

I tried to project satellite image of pixel size 2.5m*2.5m. It's in wgs84 UTM zone 44 North. I tried to project it to nepal_87 but failed. The error massage displayed was 'error-000289,failed to alter ...
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2answers
49 views

Adjusting extent of raster?

the coloured file contains landuse information and it needs to have the same number of columns and rows as the DEM in the background for further processing. i can't get it to work - "clip" and ...
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18 views

Calculating maximum mean temperature of the coldest month with a lists of rasters

I need calculate the maximum mean temperature of the coldest month. I need first select the coldest month in a list and then in this month determine the maximum temperature. I do this: Create the ...
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12 views

fail to convert polygon to raster

I have a shapefile with 520 districts each with a value. I am trying to convert this shapefile to raster using feature to raster tool. Input feature: myshapefile Field: value Output raster: ...
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1answer
39 views

Different number of columns and rows in raster datasets

currently I am dealing with the creation of a landuse file. I have geoprocessed a google earth .tiff-file over my DEM and created three polygon featureclasses via the editor tool containing areas of a ...
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15 views

Error in merging two raster files (precipitation) in QGIS

The newly computed geotiff shows the extent of both raster layers, but only the data of one. If I use identify features tool it gives me only the values of the visible part not of the other part. I ...
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18 views

Change detection between two Landsat scenes? [duplicate]

I want to do time series analysis and find change in NDVI. I have rasters where each pixel is represented by some value at a time. Also I have same thing but represented by points. And I would like ...
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16 views

Raster images overlaying each other but shouldn't

When I open a new map document and drag different raster images into the map the images stack on one another rather than form the complete image of a country. When I try zooming in, the multiple ...
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2answers
70 views

Raster image thresholding using python

I would appreciate if someone could guide me for applying thresholding technique to input raster image using Python. I intend to extract impervious surfaces from a high resolution raster such as ...
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18 views

Maxent does not create the distribution map

I've been using Maxent to run a model, the program produces multiple output files except the html file, the map pictures and the distribution map or raster file (.asc). Does anyone know why this could ...
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1answer
35 views

Enabling: Raster and Topology

I'm new to GIS and tile servers. I've installed TinyOWS pretty successfully except for what looks like to be some dependency issues. I have installed PostGIS and also PostgreSQL. PostGIS is supposed ...
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11 views

Recentering a tiled raster table in PostGIS?

Does anyone know a nice and easy way to recenter a tiled raster table in PostGIS? By recentering I mean that I have a raster that is centered on the Pacific, but I need to recenter it on ...
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1answer
37 views

Interpolation extent

the following pics will hopefully explain my problem. After interpolation an clipping the grid I get the result you can see on the pic. Next to the boundaries there are a lot of gaps caused by the ...
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2answers
56 views

Problem when opening a raster layer

I am a news user with QGIS API C++. In order to feel good with it I try some little program to explore class. I have download the tutorial 4 of the QGIS and adapted it to the 2.8 version but when I ...
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2answers
39 views

How to use r.mapcalculator to change values within a raster cost map to negative

I have created a cost map in r.cost module in GRASS (through QGIS). This is actually a distance map from a protected area and distance from protected area has been calculated in both directions. How I ...
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2answers
38 views

add multiple rasters, each located a branch too deep in separate folders - ArcGIS

I have a year of daily raster datasets (365) that I would like to use the Cell Statistics tool on; however, each raster is located in a separate folder so I cannot add all of them at once. ie: ...
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1answer
99 views

R - How to “smooth” a raster map

I am trying to create a map from raster data. The file came from a crop model, with resolution of 0.5 degree. Even when I disaggregate it (i.e. increase spatial resolution), the map looks really ...
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37 views

NDVI from raster to vector isnt working

I have question...can I make from raster img. vector file via qgis? Because Ive tried it on NDVI image and Ive only got one file with atribut table full of #null. Image is from landsat7... ...
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31 views

Obtaining NDVI data from selected area

I need to analyse NDVI (-1/1) change between years (05-10y). But still only under selected shapefile. To analyse the extent of each NDVI category. Any tips? I have tried to make vector from the NDVI ...
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1answer
20 views

Extract maximum raster value within a set radius to a point

I have lines (rivers) that don't exactly match a raster grid (flow accumulation). If they were exact, I could just extract the raster values to points I put along those lines. However the raster ...
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1answer
25 views

How to input Shapefile point data into a raster and have the raster adjust to the new data?

I have a shapefile with elevation data at specific points. I also have a raster that has incorrect elevation values, but the transition between pixals is what I need. Is there a way to put the values ...
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15 views

Raster alignment terminology?

I identify two types of raster alignment (assuming SRS is the same), but I am unsure of the correct terminology for these (or whether there is even a 'standard')? First, there is 'pixel alignment'; ...
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3answers
42 views

Creating a new raster layer based on mean of other raster layers, ignoring NA values in R

I am trying to create a new raster layer that is made up of the mean values from 7 other raster layers. I get results using overlay function mean: mean <- overlay(2000, 2001, 2002, 2003, 2004, ...
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21 views

plot rasters with the same line diagram

I have 6 raster files with continuous values for an area with the same extent. I have created a raster stack and I want to plot one line for each cell in the raster stack of my six rasters (like the ...