Questions tagged [raster]
Raster is a data format consisting of regular grids of values, usually stored in an image-like format.
9,061
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What defines Class in Heat map plugin?
What defines a Class in the Heat map plugin?
As in:
Black holes like that are usually caused by raster values exceeding
the range of the color ramp. Try adding another class with a
higher associated ...
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2
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Translating grid to USGS .dem in C# via GDAL
I am attempting to translate ArcInfo binary grids to USGS DEM format (.dem). I have installed the GDAL .NET bindings thru this build installer. I can get to GDAL in my C# add-in I am working on. ...
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2
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Moran's I on 2D arrays/rasters?
I would like to apply Moran's I spatial auto-correlation measure to 2D arrays or raster files in Python and I am wondering if there is an available implementation for it.
I know Pysal offers an ...
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Determine rasters particular area's within ranges using python
My directions:
Create a script that determines what areas meet the following
conditions:
Moderate slope — between 5 and 20 degrees
Southerly aspect — between 150 and 270 degrees
Forested — land ...
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Alternatives to Zonal Statistics which include partial pixels (QGIS)
The task I want to complete is essentially exactly what the Zonal Statistics plugin for QGIS aims to achieve: gives statistics about the values of a raster layer in areas defined by polygons.
However,...
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2
answers
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I can't find the Georeferencer
I'm using QGIS 3.26 and I can't find the Georeferencer.
I've basically looked everywhere. It should be in the raster section, but it isn't there. I checked all of my plugins if there was anything, but ...
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Dates are off when opening netcdf file in R
I have a netcdf file with the time dimension that goes from 12/2007 until 12/2010 with monthly time steps. I can see the correct dates in both arcgis and panoply. Panoply tells me this file is a ...
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How to calculate NDSI of a specific region from an image collection?
I want to calculate NDSI using Landsat8 data for 2015 - 2020 specific months to prepare binary snow cover maps (NDSI > 0.4) and then export all images based on my boundary area.
I tried the below ...
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Substracting rasters by minimum values (loop over list) using R
I'm trying to reclassify a bunch of rasters by substracting the pixels of each of them with their minimum value (eg: I want to substract all the pixels of a raster(A) by its minimum value, same thing ...
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4
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1
answer
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Importing multiple raster files into one GeoPackage
I'm looking for an alternative to import multiple raster files into a GeoPackage other than dragging and dropping via QGIS Browser (sometimes takes to long or returns error).
Following this post I'm ...
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1
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QGIS 3.22.7 - Trouble converting vector to raster (ERROR 1: Wrong value for -ts parameter)
I am learning QGIS, and I have a series of polygons that I need to turn into a raster. The shapefile I am working with can be downloaded here (shapefile size is 3 KB). I am using the Rasterize tool, ...
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Change the resolution of the friction surface raster and compute cumulative travel time in R
I have downloaded the 2015 friction surface from the Malaria Atlas project website (see bottom of the page). On their websites, authors specify that the measure units of such a raster are minutes to ...
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3
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2
answers
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Exporting raster with transparency from QGIS
As a follow on from my earlier question on reprojecting raster images - is there a way to export a reprojected PNG file (with transparency) from QGIS, with an associated world file?
I can now ...
CommunityBot
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1
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How to create custom tool via Python that selects by attribute, then outputs new feature classes
I am trying to create a custom tool via python script that selects features in multiple fc's within a feature dataset that are missing values, then from the selected features, creates two outputs: one ...
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Rasterizing polygons in rasterio error: "ValueError: operands could not be broadcast together with shapes"
I am trying to take shapefile Boroughs3.shp and rasterize each polygon (row) as its own raster layer, where each new raster would each contain a separate and isolated rasterized polygon. For context, ...
CommunityBot
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Doubt about attribute table in R terra package [closed]
I built a classification algorithm using rf and realized maps using predict function of the terra package.
The variable I used for classification had 3 different levels.
Following the indications on ...
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1
answer
16
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Performing a k-means clustering with raster time series
I would like to perform a k-means clustering on time series data. I tried doing it with rts package.
library(rts)
path <- system.file("external", package="rts")
lst <- list....
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2
answers
31
views
How to crop an ASCII file?
I have data downloaded from https://sedac.ciesin.columbia.edu/data/set/gpw-v4-population-count-rev11. It is in an ASCII file, and I want to plot the map and the populations of just California. What is ...
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Projecting rasters, shift to the north
I would like to project one raster onto another and while doing so I think the values are changing their position "to the north".
Is this an expected behavior?
I was hoping to create a ...
- 131
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vote
1
answer
20
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QGIS 3.22.8 Raster sampling with polygons
This is a DEM of a slope. I have made a polygon grid 10X10. I can't find a command to sample the raster by polygons. I've thought something similar with r.neighbours picking the minimum value of the ...
- 677
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Mean of NDVI rasters across time point in QGIS after removing bad quality pixels
I have several NDVI and EVI rasters from different time points across a study period. These are of a region in Burkina Faso, and during the rainy season pixel reliability can be low. I have first ...
- 14.2k
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1
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How to "mosaic" rasters and keep attributes
I have numerous individual 10m Raster files (with both quantitative and qualitative data) for each state and need to combine them into a national dataset.
However, when using a mosaic it seems that ...
CommunityBot
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3
answers
154
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Calculating grid file area using MapInfo Pro
I have MapInfo Pro and a raster .grd file that contains signals strength levels for different locations. I want to calculate the total area of the .grid file.
Would there be an easy and quick way to ...
- 7,378
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1
answer
508
views
Comparing point pattern and raster data?
I have a simulated data set showing distribution of a certain habitat type as a point pattern.
Then I have a empirical data set but there the format is raster.
The two datasets are covering the ...
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1
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Raster export resolution using ArcMap
I'm trying to export a portion of Natural Earth's world 10M hillshade in ArcMap but above a certain latitude, the resolution unexpectedly changes and is really poor.
This is a screenshot of the area ...
CommunityBot
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1
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36
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r Terra Mosaic Raster uses huge amounts of memory and takes too long - any alternatives?
I built a process using google earth engine code editor to output a raster of urban land cover in Wisconsin. Google exports these as 210 shard which are geotiffs ranging from 2-100mb in size. Most are ...
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1
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133
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Binning of satellite Level 2 data
I can see that for the Aqua instruments (AIRS, MODIS, CERES etc), the Level 2 data are binned into Level 3 data providing average values for (say) a 1° x 1° cells grid.
Let's say that I would like to ...
CommunityBot
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0
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Get element in raster array based on BNG coordinates
I have some BNG coordinates which are converted from lat and long using proj4. I also have a raster file based on BNG. I want to get the relevant element from the raster array based on the coordinates ...
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1
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98
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Opening scripter in Whitebox GAT?
I am trying to open the scripter or scripting tool in Whitebox GAT so that I can edit Export GeoTIFF tool to make Whitebox export a TIFF file from dep/tas format, which was suggested by Whitebox ...
CommunityBot
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0
answers
22
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Unable to setup geoserver WMS layer as a background map in Qlik
When trying to add a WMS layer from geoserver in QLIK, despite being able to see the list of layers from different links, these layers don't show on the map.
For example, when trying to follow this ...
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2
answers
214
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Increase the dimensions of each cell in a raster without any kind of resampling?
I have a DEM interpolated from a TLS point cloud at 1 mm cell resolution. This resolution is too fine for use in a 2D surface inundation model with the required timestep, without the model taking far ...
CommunityBot
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1
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232
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Identifying spatially contiguous clusters in raster data using R
I am doing a classification of z over a single raster of dimension x,y,z.
r <- raster(nrows = 200, ncols = 400, xmn=-1, xmx=1, ymn=-1, ymx=1)
r[] <- sample(1:100, size = 80000, replace = TRUE)
...
CommunityBot
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1
vote
2
answers
796
views
Stitching Sentinel 2 neighboring images in QGIS
I'm working with Sentinel 2 imagery, and don't know how to stitch neighbouring images. The problem is that the region im analyzing is on the border of the orbit, and there's a region with no data.
How ...
CommunityBot
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1
vote
1
answer
63
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I get a constant for the whole raster by subtracting two rasters in R and QGIS
I have two raster in brick format, as a result of previous operations, they have the same characteristics. When I try to make a simple subtraction between the two, it gives me a constant in all my ...
CommunityBot
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votes
1
answer
19
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Extract values from raster matching csv and raster filenames
I have a folder with many csv files. Each file has several columns as well as lat and long columns. Another folder have many rasters in tif format. The .csv files are named based on Julian date (e.g. ...
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1
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views
Aggregate Fishnet's Cells into 10 cells by 10 cells grid
How can I generate an ID variable taking a different value for each 10 cells by 10 cells group in a raster?
Below is my code, built from this example.
In this example, each cell get an id (i.e., the ...
CommunityBot
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1
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0
answers
26
views
How / is it possible to extract polygons from raster (ex: crop boundaries from satellite imagery)?
Is there any librairies/tools/others that can extract polygons out of crop boundaries from a satellite imagery. On the example below (random location in Belgium), the various fields limits are very ...
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views
Why referenced or derived mosaic datasets do not project rasters of different coordinate system correctly on-the-fly?
I am using ArcMap.
I have many mosaic datasets in a projected coordinate system and I would like to project them into another projected coordinate system (different datum), but without locating and ...
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Getting extent of raster in ArcMap to 12 decimal places
I have a raster file in arcmap and want to get the extent of the raster to 12 decimal places, the extent in properties gives 9 places.
Does anyone know how I can increase it?
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Soilgrids - Using VRT format in R
Is it necessary to use GDAL when trying to use VRT files in R?
Raster Attempt
Following this answer I tried:
link <- "/vsicurl/https://files.isric.org/soilgrids/latest/data/clay/clay_0-...
- 63.8k
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vote
2
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Write raster file using rasterio in Python?
I am trying to follow a tutorial for computing NDVI (Normalized Difference Vegetation Index) through the rasterio package in python, however, I am unsure how to finish the task by actually creating ...
CommunityBot
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1
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Looping to do cloud mask for several raster files in R [closed]
I have over 200 land surface temp (LST) rasters and I want to mask each LST raster using the corresponding cloud Mask raster. The working directory has two folders one for LST and one for cloud Mask. ...
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2
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498
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Preserving coordinates when converting TIFF image to numpy ndarray
I have satellite image that I want to convert into numpy array (and then to Pandas).
I already know how to do that, but the problem is that it does not preserve the coordinate data.
This is how I do ...
- 63.8k
2
votes
1
answer
173
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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 ...
- 63.8k
1
vote
1
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237
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Mosaicing non-overlapping rasters in QGIS
I have a set of georeferenced rasters that I want to combine in a seamless layer in QGIS. I believe what I have to do is clip them by mask layer and then build a virtual raster. There is an issue ...
CommunityBot
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0
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Saving PostGIS raster as netCDF from SQL Error
I am trying to save a raster table in PostGIS as a netCDF file. When doing so, I get the following error:
rt_raster_to_gdal: Output GDAL driver does not support CreateCopy and/or VirtualIO.
Reading ...
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votes
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R: Cannot create a RasterLayer object from this file
I need to download the climate data from CHELSA in form of GeoTIFF file. I need many layers, for which I downloaded them successfully but failed to load them as raster. For simplicity here is how to ...
- 52k
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Plotting a buffer polygon over wrld_simpl
I want to create a buffer around a set of spatial points and plot it over wrld_simpl, without using ggplot2. Yet, there seem to be some issues with the projection I do not quite understand.
here is my ...
- 8,906
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2
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489
views
Rasterio merging went wrong
I try to merge some multiband rasterfiles (Sentinel 2 data) with Rasterio into a single rasterfile but the result is incorrect.
The files are too big to fit in my RAM completely, but I have enough ...
CommunityBot
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1
vote
1
answer
26
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Subtracting area of a specific set of raster values from polygon area using QGIS
I am currently working with parcel data and a raster slope analysis in % change I created with DEM data. I symbolized the slope analysis discrete 0-2.5%, 2.5-5%, 5-7%, 7-12%, 12+% and overlayed it ...
- 63.8k