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

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Convert raster to smooth contour polygons in QGIS

I have had limited success creating smooth contour polygons from a raster layers. I have created contour lines and boundary polylines and then used QGIS Union. Then I use QGIS Polygonize. Then ...
2
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2answers
30 views

Raster to KML convesrion [duplicate]

How raster data can be converted to KML? I have searched but could not find any answer. Are there any tools in Arc toolbox for such process ?
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12 views

How to query raster in PostGIS within GeoJSON mask only

I have a raster in PostGIS which I need to query pixel values from, but only within a specific area. So I have a GeoJSON polygon within which I want to extract min/max/avg values of the raster from. ...
1
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1answer
29 views

How to set the outline color of raster cell (pixel)?

Can somebody please show me how to set the outline color of a raster cell (pixel)? This is what I have right now: This is what I am trying to do: I googled a bit, and looks like it is somewhere ...
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0answers
14 views

R Freezes when Plotting Spatial Data Frames

I have run into a problem where anytime I try and plot a Spatial DataFrame in R, the console freezes, regardless of the size of the file. I imagined this must be due to an issue with the path to one ...
1
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1answer
20 views

How to work with Baccini et al.'s biomass map from ArcGIS?

Baccini et al. (2012) has produced one of the best biomass maps available for the world. One can find the map from one of ArcGIS repositories here. I downloaded the .pkinfo file for that map but I ...
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0answers
21 views

How to get all pixel values of raster within a GeoJSON FeatureCollection in PostGIS

I need to extract all pixel values in a raster within a GeoJSON mask, using ST_Intersects. Attempt (throws invalid GeoJson representation): select row_to_json(t) from (select * from table_name where ...
1
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1answer
22 views

Error in rasterToPolygon trying to get several coverage layers

I have a very strange problem: I am trying to get a raster with coverage from 0 to 1 in each cell for types of vegetation, I started with a raster of vegetation type, but I needed a raster with 12 ...
0
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0answers
14 views

How to calculate the world file [duplicate]

I have map image of size 2500x 2500 and i know the extent of the map image which is xmin=454651.17794, Ymin=2738724.37939,Xmax=550197.46330 and Ymax=2834270.66475. The Xmin and Ymin calculated from ...
3
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3answers
119 views

Statistics on classified raster overlaid with a polygon vector

I have a classified raster file and a polygon vector file. I need to overlay polygon and find out area occupied under each classification in each polygon. I am not familiar with R. Can you please ...
4
votes
4answers
147 views

How to speed up raster to polygon conversion in R?

I've decided to process my Landsat data in R instead or ArcGIS - due to my missing knowledge of python and and because of (assumed) high computation capacities of R. I want to : import r1 raster to ...
2
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0answers
53 views

Size of an object in raster image based on DPI resolution and number of pixels

I'm trying to estimate the size of an object in a raster image, with known DPI resolution. To evaluate the validity of this method, I do as follows: 1) I'm drawing a 0,02 in × 0,02 in black square ...
6
votes
1answer
100 views

Why does the difference between two overlapping rasters exist?

I have two similar rasters of the Mount Vesuvius: one spans 20 kilometers, and the other one 50 kilometers. Both rasters are in WGS84 geographic coordinate system, and they overlap between each other: ...
6
votes
2answers
171 views

Transforming geostationary satellite image to lon/lat

The ICARE Data and Services Center distributes the SEV_AERUS-AEROSOL-D3 product in HDF5 format (http://www.icare.univ-lille1.fr/archive/?dir=GEO/MSG+0000/SEV_AERUS-AEROSOL-D3.v1.03/). The main ...
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1answer
42 views

Building georeferenced GeoTIFF from mbtiles automatically?

I want a georeferenced raster.In that way I don't have to georeference this raster manually . I know that geotiff has the georeference inside it , I got the mbtiles of the map how do I build the ...
6
votes
2answers
89 views

How to calculate the difference between two rasters in QGIS?

I have two similar rasters of the Mount Vesuvius and surroundings: one spans 20 kilometers, and the other one 50 kilometers. The two rasters are overlapping: What I would like to do is to create a ...
0
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0answers
50 views

Call gdal_proximity() from R

I have a raster including eight land cover types (pixel values ranged from 1 to 8): > r class : RasterLayer dimensions : 9887, 30532, 301869884 (nrow, ncol, ncell) resolution : 10, 10 ...
2
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0answers
19 views

How to generate random points from classified raster layer?

I need to generate random points using a raster layer, which is classified into 5 classes of TPI (terrain position index). This should be a stratified random sampling design, with an equal amount of ...
3
votes
1answer
51 views

Importing large .asc files into QGIS

I've been given two .asc files containing a 1m raster data from a LiDAR survey. I only have access to QGIS.2.14.1 (which I'am using for the 1st time only having previous experience with ArcGIS) and I ...
2
votes
1answer
54 views

Recommendation for getting TIF raster from modis HDF, for processing in R

I've downloaded a set of modis mod13q1 HDF files, e.g. MOD13Q1.A2016097.h11v05.006.2016114040325.hdf. I'd like to load the 250m_16_days_EVI and 250m_16_days_pixel_reliability bands into R as rasters. ...
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0answers
6 views

How do I display NAD 1927 Albers with other data?

I have some raster datasets which are in NAD 1927 Albers projection. I cannot seem to display any other type of data with this projection. I get the pop-up projection warning when trying to add a ...
2
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0answers
14 views

Issue loading PostGIS out-db rasters (either in QGIS or MapServer)

I'm playing with a few different options of storing raster data via PostGIS to visualize (eventually in a web app). The out-db or out-of-database storage seems the best option, but I can't seem to ...
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0answers
23 views

Zonal Statistic Tool

In ArcGIS, I have a grid 5x5km (I have it both in vector and raster formats) I want to calculate, based on this grid, the zonal statistic (MEAN) of a raster 30x30m pixel size. The raster overlaps ...
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0answers
22 views

Raster Precision QGIS

I am using r.patch extension in QGIS to join a number of LiDAR tiles, some of which overlap hence i am carrying out this task before utilising in a hydraulic model. R.Patch works fine, however the ...
2
votes
1answer
35 views

How do I change the pixel values of raster data from QGIS python plugin

I have been trying my hand at a QGIS plugin. The plug in reads raster layer data into an array, pipes the data to a C++ program, does processing over there, and pipes my results back. After a couple ...
0
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1answer
24 views

How to merge rasters with the same but unequal cell size in ArcMap?

I'm trying to merge raster tiles that all have the same, but unequal cell size (X: 2,8, Y: 2,9). When I use the Mosaic To New Raster tool, I can enter ONE cell size which either results in a raster ...
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1answer
21 views

Raster to point

I have a raster (5km pixel side) and I want to create a shapefile of points, one point per pixel (like a centroid), each point carring the correspondent pixel value. I run "RasterToPoint"tool in ...
2
votes
1answer
40 views

How can I calculate the percent of a raster cell covered by a polygon?

First, I am going to try and intersect a raster and a polygon shapefile. I'm not 100% sure how to do this (or if I need to do this for the next step), so if you have any suggestions please let me ...
-1
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0answers
29 views

Calculating total area overlapping raster DEM color interval whose boundaries are confined by another vector? [duplicate]

Example: I tried running raster calculator on intersections then zonal statistics checking "count" and "sum" but I get a huge table of 8000+ rows and two columns, however each cell usually have a ...
1
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1answer
41 views

Generate ESRI grid with xllcenter/yllcenter in header

I'm trying to generate ARC/INFO ASCII GRID (*.asc) from point feature class using Create TIN - TIN to raster - Raster to ASCII functions. I'm looking for a way to have the output raster file header ...
0
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1answer
22 views

How to extract single band from multi-band radiometry raster using R?

I am having trouble extracting single band from multiple multi-band raster. I have no problem doing it on single raster file. Is there a way to loop through all the raster images to extract a single ...
0
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1answer
49 views

Exporting Raster from SAGA and importing it to QGIS - error CRS was unidentified

I make raster files from LiDAR las files in SAGA - CRS of .las is Slovenian national Grid. Then i export it as GeoTiff (Import/Export - GDAL/OGR - Export GeoTiff). When i import it into Qgis (Project ...
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0answers
24 views

Selecting cells with values from DEM those are above specific value corresponding to each polygon?

i have a shapefile with 2000 polygons and a DEM. i want to calculate zonal mean for each polygon considering values from DEM which are above a particular value for each polygon. i want to it with ...
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1answer
24 views

“First” and “Last” from Global Forest Change [closed]

What are the "first" and "last" rasters provided by the Global Forest Change data set?
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2answers
29 views

How to export vector file in GrassGIS to QGIS

I am using GrassGIS to analyze watershed. I created a stream vector extracted from raster elevation data, how to extract the stream vector file so I can open it using QGIS?
5
votes
1answer
94 views

Krovak projection EPSG 5514: Correct data transfer between R and ArcGIS?

I have a problem which many ArcGIS, QGIS and R users from Czech Republic and Slovakia may encounter. In ArcGIS, I am working EPSG: 5514, Projected Coordinate System, defined as: ...
1
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1answer
33 views

32-bit Map tiles for use with leaflet

I've got a lot of single-band Geotiff files with the GDT_Float32 format and I need to present these over the web, hopefully using a webmap leaflet/mapbox/googlemaps widget where clients can hover over ...
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28 views

Why ArcGIS crashes when I load raster file created in R? (HFA format)

I was processing my raster operation in R, as I think it's easier then in ArcGIS: - read shp + raster1 - crop them - classify raster1 by location - create classified raster2 - export the ...
0
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0answers
29 views

Create a grid over shapefile then save each section into GeoTIFF

I have a massive shapefile with 200,000+ building polygons. I've loaded these up in ArcGIS. I need to convert this into a usable raster (GeoTIFF) that can then be tiled using MapTiler. My current ...
1
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1answer
40 views

Reclassifying raster analysis (like the one in ArcGIS Spatial Analyst) in QGIS [duplicate]

I am trying to reclassify raster (DEM) in QGIS. I know how it is done in ArcGIS (Spatial Analyst, reclassify option), but I would like to know how it is done in QGIS?. The point of my exercise is to ...
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1answer
43 views

Convert a raster with one band into a raster with RVB bands on QGIS?

So yesterday i downloaded a raster tile on a WMS server and exported it with Grass. I get a raster with 3 bands, i treat with the Semi automatic classification Plugin in QGIS and it works perfectly. ...
0
votes
1answer
20 views

How to I change the extents of a Euclidian Distance Raster?

I am calculating the Euclidean distance of a set of points. The output raster truncates the resulting raster image to the farthest north, south, east, and west point. I need the distances to extend ...
0
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2answers
22 views

mapping with spplot

This question should be easy! I am using spplot for visualizing a map with suitable results. However, I would like to know how to set the limits of z, because the values are not being discriminated. ...
5
votes
4answers
153 views

ArcGIS 10.3: Insert rotated image without background

How can I insert this image into an mxd so the white background doesn't show up? I've tried using photoshop to delete the background and save it as a format that supports transparent backgrounds (gif ...
0
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0answers
21 views

Problems to export raster files in R software

I'm working with R software with raster and netcdf4 packages adn netcdf files to get information from SST. I got the information and now I'd like to convert in ascii or geotiff files to work in ArcMap ...
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0answers
24 views

Polygon to Raster: Cells with multiple values

I'm trying to use R to rasterize a number of shapefiles and I'm having trouble dealing with cells on the edge of shapes, in other words the if a cell is partially covered by an NA value and partially ...
3
votes
1answer
28 views

Problem with algebra formulas for work with gdal_calc.py

I'm trying to update some values of a raster based on another raster. 1st raster (A): landuse data (values from 10 to 240) 2nd raster (B): mask data (only nodata values and a given value, for ...
0
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1answer
23 views

Extract elevation values from WMS DEM to points

I have a points feature class that I am trying to get elevation values for the state of texas. ArcGIS Online conveniently has a DEM for the entire state as a WMS. I am wondering if there is a way to ...
2
votes
1answer
13 views

Quartiles from Raster Layer band

I'm building a plugin from QGIS, and I need to extract the values from the quartiles from a band in a raster layer. Does anyone knows how it is done?
0
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0answers
19 views

Read GeoTiff from memory in GDAL

Is it possible with the GDAL library to read an image (e.g. GeoTiff) from a memory stream, like stdin instead of a defined location on the local disk? It would be useful to read data in streaming ...