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

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Rasterizing polygons with the function “gdal_rasterize” in R

I'm using the function gdal_rasterize in R (package gdalUtils) to convert a polygon shapefile into a raster. Here is my code: r.test <- gdal_rasterize(src_datasource="df.shp", ...
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12 views

Calculating water flooding with raster calculator

I have many layers so i will try and explain what all the layers are. What I want do is enter a calculation in raster calculator to calculate what areas of the map will be flooded if the water levels ...
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10 views

How to get a multi-attributes vector from an SRTM raster in QGIS?

I split an SRTM raster into 3 different raster files representing the altitude, the slope and the exposure, using QGIS DEM analysis tools. How can I output a single vector file with the 3 attributes ...
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13 views

Raster images in geoserver without WMS

Is there any vailable way to access raster images through geoserver without wms?(to a large number of images)
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21 views

Changing point data coordinate system without moving points in QGIS?

I made a mistake regarding coordinate systems and lining up two layers. I have a raster with elevations in EPSG:2949. I created a point data shapefile and entered about 600 hundred points manually ...
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19 views

Extracting the cell size of a Raster as a value to use in buffering

I am creating a model in ArcGIS modelbuilder to buffer a line. I would like the buffer distance to be based on the cell size of a raster. The cell size may change depending upon which raster the user ...
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2answers
24 views

ArcGIS Multiband Raster

I know this has been asked and answered here but since I don't have enough rep to ask a clarifying question to the person who answered it I am having to post a completely different question. I am ...
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1answer
14 views

Inverse Distance Weighted (IDW) Interpolation with Radial Basis Function (RBF) in R

I want to perform an IDW interpolation with R. I am aware that I can do that with gstat::idw. But I want to change the parameter 'idp' with a radial basis function (RBF): where is the ...
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27 views

R: count raster values using another raster as mask

I would like to count the frequency of values in one raster, using another raster (different resolution) as the zonal condition. The premise is that the coarser resolution raster represents the area ...
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2answers
29 views

aggregate raster using the most frequent value

Does anyone have an idea how I could aggregate my raster so that in the output the most frequent value is used, as shown on the picture?
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1answer
50 views

Building predictive maps of response variables in R

I am a novice in spatial statistics in R. So, I am looking for some advises. In particular, I would like to create a predictive map of capture success from a generalized linear mixed-effects model ...
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28 views

Plotting Raster in R gives error

I know this is not much to go off of, but I can't seem to find the answer anywhere. I was plotting this raster image on Friday and it worked, and now when I try to plot it, I get this error. The image ...
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30 views

Contour extraction from raster does not finish in Qgis. How to find out if a raster is damaged

Execution of "extraction" - "contours" in Qgis is impossible. The process never finishes, I stopped it after 35 min. The contour extraction works for all other raster files. I have tried with ...
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22 views

Tearing of SpatialLinesDataFrame and problem with gClip function

I am trying to use ggmap with geom_map and geom_path commands to add a SpatialPolygonsDataFrame of African countries and a SpatialLinesDataFrame over a raster. When I use the defined function gClip() ...
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15 views

Combine latitude, longitude and value ascii files

I have three ascii files of latitude, longitude and value. How to combine these three ascii files into a single raster of GTiff format?
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1answer
38 views

How to derive a hydrologically correct DEM from point shapefile using QGIS?

I used grass gis v.surf.rst function to interpolate a surface using vector points. But it is very difficult to find a optimum parameters to be used. I am still unable to develop a accurate terrain
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1answer
14 views

PostGIS update data with ST_Tile

I need to update tiled raster data from the "whole image". I have created this query: UPDATE data_tiled AS t SET raw_data = f.raw_data FROM ( SELECT data_time, data_type, ST_Tile(raw_data, 250, ...
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1answer
33 views

Getting different pixel depths from output raster when done in ArcMap versus Arcpy?

When I use 'Plus' in Spatial Analyst to add together two 8-bit unsigned rasters (pixel values 0-100) the output raster is 8-bit unsigned (pixel values 0-200) but when I try and do the same thing ...
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raster doesn't redraw to fit the canvas after a zoom in and a pan

i am working with qgis 2.8.2, c++ api and qt 4.8.5 i have a layer in the mapcanvas, this layer contains a raster ( a georef tif picture ) when i zoom in, the raster fill the entire canvas , ok but if ...
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1answer
26 views

Combining rasters using weighted average

I am using ArcGIS 10.3 with spatial analyst. I have a series of several rasters that I am trying to combine into a single raster layer. The rasters are all different sizes (different extents) and were ...
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1answer
18 views

How to merge raster with FME with different spatial resulution?

I have two sets of raster (tiff, aerial photos) which I want to merge to one raster file with FME. The two sets have different spatial resolutions. Set A has a better resolution as B. The two set do ...
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1answer
26 views

Pattern fill for raster contours in QGIS

How do I fill the area within raster contours with a pattern fill, instead of colors in QGIS? Is this even possible?
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1answer
58 views

How to find the height information from LiDAR point cloud data [duplicate]

I need to find the biophysical parameters(biomass) from the LiDAR point cloud data. For that I need the height of the trees from the data. Currently I am having the general height with respect to sea ...
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1answer
26 views

QGIS: Only view raster data within polygon

So i have this raster dataset in .ASC-format. I defined a bounding box polygon of my study area: Now i want QGIS to only show the raster data within this boundary box without changing/adapting the ...
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24 views

First time rasterio error

First of all, I am new to python and rasterio. I am trying to open a simple raster with 5 bands using the rasterio module in python. This is what I am trying to achieve: import rasterio with ...
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60 views

PostGIS convert point->raster->GeoJSON

My question is a follow up to Convert a raster to GeoJSON polygons in PostGIS I'm trying to accomplish querying point data from the database, and then turn that into a raster for calculating ...
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33 views

Geoserver ImageMosaicJDBC problem with interpolation setting

I use the ImageMosaicJDBC plugin to connect to an Oracle raster table. Maybe someone can clarify some things about the interpolation settings. There are multiple location where I can define the ...
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I would like develop an Android GIS app which should support offline navigation [closed]

I would like develop an Android GIS app which should support offline navigation, that means it should allow to downnload offline maps such as toposheets which were convertred into .KMZ format. Android ...
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27 views

create a grid and extract species and climate data [closed]

I am looking for R support to arrange my dataset which I tried and failed in Arc GIS. If you have an idea please let me know. I have 6 bioclimatic variables and 14 species. I want to create a ...
3
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1answer
34 views

Spatial join of raster data in QGIS

How do I perform spatial join of raster data in QGIS? I have raster soil data (tiff), I'd like to join this to an attribute table in excel? I'm not able to view the attribute table either? Is this ...
2
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0answers
50 views

Why azimuth result is wrong for this pyqgis code?

In this code I want to obtain azimuth from a single point to each pixel center, but when run it, in raster created azimuth result for each pixel is wrong, what is correct code? from osgeo import ...
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1answer
37 views

Spearman correlation between two rasters in R

I have two rasters of the same area. The only difference is that they were created using two different methods. I would like to compare them and see how correlated they are pixel by pixel. Any ideas ...
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51 views

R raster() function failed to read tif file

I wrote a few lines to load data in TIFF to R. The function I used was: library(raster) test <- raster("file name.tif",package="raster") and it worked perfectly last week. However, now I am ...
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Grid buffer in QGIS

I do have a raster file (grid) which I have processed before with the SAGA kriging tool. Is it possible to buffer this raster file a little bit (expanding the interpolated result) of 1 or 2 grids? I ...
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31 views

How to calculate average value of a raster, that is clipped by multiple polygons?

I am using QGIS 2.12.0. I have a raster of coherence value (SAR interferometry) and a land use shape. I wish to calculate mean coherence value for those areas with a specific land use. I split land ...
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20 views

Error 010422 when combining rasters

I have 17 rasters, some of which overlap one another. I wish to combine them such that where the rasters overlap the sum of their values is taken. I have tried combining them using raster calculator, ...
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1answer
28 views

QGIS Raster Calculator syntax

I have tried this several different ways and get lots of NaN. I need to specify that in my raster 'test1', I want a certain set of values to equal 1 and the rest to equal zero. For instance, I want ...
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1answer
30 views

How to extract all pixel values in a raster file

I have a image difference from ArcGIS, which i have performed a remap function on. The layer is a temporary layer and does not have an attribute table, i need all the pixel values to do a frequency ...
3
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2answers
43 views

Align raster to fishnet using ArcGIS 10.3

I am having some trouble aligning a raster (elevation) to a fishnet I created. The cell sizes for both the raster and the fishnet are 30x30 meters. I have tried using the clip and extract by mask ...
2
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1answer
29 views

problem when doing algebra with raster layers in R

I'm trying to combine bioclim raster layers to create the following layer. (Q) = AnnPrec/[(Tmax+Tmin)*(Tmax-Tmin)]*1000 For that, I import a bioclim stack: envirc = ...
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23 views

gdalwarp error cropping raster

I'm getting an error from gdalwarp using the following code: gdalwarp -cutline input.shp -crop_to_cutline -dstalpha input.tif out.tif Error: *** Error in 'gdalwarp': free(): invalid pointer: ...
2
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1answer
98 views

Huge file size after averaging two rasters

After I average two raster files (singleband gray, initial size ~700MB each) through QgsRasterCalculator() with formula "Raster1@1/2 + Raster2@1/2" the size of the resulting file is 2.9GB. Is there ...
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0answers
17 views

Adding a custom color scale for a sp.points layer to levelplot() legend

I'm wondering how I can add a customized color palette that I used to display a sp.points layer in a call to levelplot (lattice plotting) in the rasterVis package in R. I used a function that Dave X ...
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35 views

How do I change my “no data” values to get “true” values in raster calculator in Qgis

I have two rasters and I want to subtract the values from one of the layers. The first raster is a altitude raster and the second raster is depth values for a lake. I would like to subtract the depth ...
4
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3answers
58 views

Merging georeferenced images that have overlapping information?

Having trouble to mosaic two overlapping .tif files. I need to merge these two images together into one resampled raster image. Unfortunately I cannot do this with my ability and resource available to ...
2
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2answers
40 views

How to bulk upload raster datasets to ArcGIS Online as separate discrete layers?

I have 18 raster datasets which I need to publish through ArcGIS online to allow users to turn on/off each layer and toggle transparency. I have the data stored in a file gdb as below: I am looking ...
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1answer
48 views

How to create azimuth raster layer by pyqgis?

I want to create an azimuth raster layer base of single point shapefile, for this I write below code that create a memory point layer that each point in memory layer is center of each pixel and have a ...
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26 views

Why do collinear ground control points create larger residuals?

When georeferencing a raster image of a long corridor, why do collinear ground control points cause larger residuals? Say I am using the georeference function in ArcMap, and I have 6 ground control ...
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11 views

How to avoid the quilt effect when displaying imagery from multiple source

In the context of creating my own imagery viewer (for educational purpose), I would like to learn about the process used to create seamless transitions between satellite imagery tiles coming from ...
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how to extract line features from a raster

I have a raster of land cover types where roads are represented by pixels (1 pixel = 25m x 25m = 625 m²). Is there a way to extract line features (here roads) from a raster ? ## Create raster as an ...