Questions tagged [resampling]
To alter the frequency of sampled data points in continuous data.
246
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Resample() function in R's terra package and the r.resamp.interp module in GRASS GIS yield such different rasters
Comparing the results from the resample() function in R's terra package (version 1.7-29), and the r.resamp.interp GRASS GIS module (version 8.2), I find differences in how they apply bilinear ...
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Which resampling method to use when georeferencing with QGIS/GDAL
Using Georeferencer in QGIS (which in fact uses GDAL library), in transformation settings you can define the Resampling method as can be seen on the screenshot. I am wondering on what it depends which ...
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How to avoid gdalwarp converting to alpha band
I am running the following code in order to resample a single-band TIFF file, whose data are going from 0 to 100 with 255 being the nodata value
"gdalwarp -t_srs "+srs+" -tr "+pxsz+...
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Reducing resolution of raster layer in QGIS: "Save as..." or "Align Raster..."?
In QGIS (Version 3.22), if I need to change (reduce) the resolution of a raster layer, I can simply choose "Save as.." from the "Layer" menu or I can use the "Align Raster&...
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Trying to resample data and the columns are off by 1
I am trying to run a MaxEnt model with layers from ArcGIS.
I am new to MaxEnt modeling but from what I have learned everything must be exactly the same in all layers. Columns, rows, cell size, ...
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Mosaicking cloud removed Sentinel2 imagery using Google Earth Engine [closed]
After struggling the cloud removing part of GEE, I have some questions regarding the mosaicking the result instead of using median().
What I learn about the difference between mosaic and median()/max()...
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Projection is not a function
I'm new to Google Earth Engine, just get started to learn how to load and process the Sentinel imagery on GEE.
Today I wanted to resample the imagery downloaded from Sentinel2 into 10m (band 5 and ...
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Reproject and resample raster1 to CRS and grid of raster2, but keeping the shape of the original raster
I am working with two raster files.
path_target: shape (27502, 6133); CRS: EPSG 31255
wk_path: shape (294825, 570431); CRS: EPSG 31287
I would like to reproject path_target to EPSG 31287 and align the ...
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1
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Avoid adding a bunch of new features for one static location for repeat sampling efforts in Field Maps
I have built several maps and forms for their use in Field Maps for various projects. Most have been creating new features and filling out the form for the new location where we sampled. However, we ...
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S2 Resampling Error with SNAP
When I tried to S2 Resampling using SNAP 9.0.0, I get an error and the processing fails. I kept all parameters default.
Error as follows,
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What's the difference between bicubic interpolation and cubic convolution?
Our remote sensing professor recently introduced us to bicubic interpolation and cubic convolution, implying that they're basically the same. Now that I'm studying for the exam, I wonder: Is that ...
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Miminum values of a raster change when applying r.resample
I am trying to aggregate a raster of a bioclimatic variable (can be downloaded here: https://envicloud.wsl.ch/#/?prefix=chelsa%2Fchelsa_V2%2FGLOBAL%2F > Climatologies > 1981-2010 > bio/ > ...
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Downsample large raster without reprojecting first
How can I downsample a large TIFF (raster) which is projected in decimal degrees without first having to reproject it to meters. I know that in meters the resolution is 3cm and I want to downsample to ...
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How to merge GeoTIFF files of different resolutions and utilize the higher resolution tile data where available
I've got a single 1/3 arc-sec GeoTIFF file covering an area and a handful of smaller, higher resolution 1 meter GeoTIFF files that cover only some of the area that the 1/3 arc-sec file covers. I'd ...
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Converting raster layer from EPSG:3003 to EPSG:4326
I am working with two type of raster layers:
The first one is a .tif file downloaded from Worlclim database that is in WGS84 (EPSG:4326) coordinates reference system. So that, the resolution is ...
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Calculation of downscale factor for downsampling image using Rasterio
I have image with resolution of 30cm in WGS84 EPSG 4326.
I want to down-scale the image to get the same image but with 50cm size of pixel.
I have used Rasterio documentation (pages 80-81) in order to ...
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Resampling Sentinel-1 GRD data - should it be converted to linear scale before resampling?
I am trying to resample Sentinel - 1 data(original resolution of 10m) to 500m in GEE platform.
#Resampling the image to 500m
def resamp(image):
resampd = image.reduceResolution(
...
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2
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151
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SRTM raster looks pixelated with hillshade style in QGIS when zooming in
I have a project and I want to create a map using SRTM as a background.
I upload it ... and it looks like that:
But my project area is smaller, so I need to zoom it ... and when I do that, my SRTM ...
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terra R package resample of non-empty raster by 'sum' produces empty raster
I have a raster x which is at a resolution of 100m and pixel value is its area in sqkm is suitable for an action, see below
class : SpatRaster
dimensions : 769, 716, 1 (nrow, ncol, nlyr)
...
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Resampling images in GEE
I'd like to resample three images into the same scale as the rainfall data in GEE. So far the code below works for Sentinel but not for the soils data which is still in 30 meters.
var rainfall = ee....
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Resampling using pyresample grid definition
I would like to resample a dataset to another projection and scale. Following the documentation in pyresample website here. We need to have an Area Definition, which is tedious to do.
import numpy as ...
3
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3
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QGIS: Resample (upscale) raster using a Gaussian filter
I want to resample a raster from 15m to 460m using a Gaussian filter.
The goal
I am having a coarse image which I want to downscale. I also have a fine resolution band to assist the downscaling. The ...
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QGIS - Converting Vector to Raster and back to vector to resample resolution of vector data
I would like to convert my polygon data into a raster file to change the pixel resolution and then would like to convert it back to polygon data since this will allow it to be resampled to another ...
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How to deal with Nan value when using rioxarray rio.reproject()?
I was trying to use rio.reproject_match() to match the resolution of two xarray datasets. However, when I used resample methods like Resampling.bilinear or Resampling.average, a large area would ...
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stratifiedSample() gives an empty feature collection in Google Earth Engine
I am trying to sample 10 random points from each value in the 'QA60' band of a Sentinel-2 image for machine learning purposes. When I use the .stratifiedSample() function, I obtain an empty feature ...
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Specifying target resolution when resampling with rasterio
In GDAL warp you can simply set an xRes and yRes value. I'm trying to only use rasterio, but the process seems a lot less clear.
According to the docs https://rasterio.readthedocs.io/en/latest/topics/...
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How can I group Land Cover Classification into urban vs rural areas and summarize Land Surface Temperature for each class in python? [closed]
I have NLCD land cover classifications from an .img file as follow:
I would like to somehow reclassify these into Urban or Rural by taking all developed as urban and the rest, minus water as rural.
...
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Zonal Statistics as table on population raster does not produce correct regional population figures using ArcGIS Pro
I have a population raster (from Worldpop.org) with data on the population count of Philippines. It is unconstrained data from 2020, 100m resolution.
Link to raster: https://www.worldpop.org/geodata/...
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1
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How does majority resampling technique works in ArcGIS?
I would like to understand how does the majority resampling technique works.
To be specific the documentation below states that the method will use a 4X4 filter and will populate the output with the ...
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Resampling high resolution data into lower resolution based on most common value
I want to use a high-resolution classification (3cm) as training data for a classification using Sentinel 2 data (10m).
To do so, I want find which high-res value is most common within each Sentinel &...
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291
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Google Earth Engine: Output too large when reducing resolution and exporting to Google Cloud
I'm calculating a bareground layer for Africa using Sentinel-2 at 10m resolution. I want to reduce the resolution to 1000m and then export it to Google Cloud Storage. However, this gives me an error ...
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Resample raster but keep sum of total cell values the same
I am trying to resample a raster to a finer resolution, matching the resolution of my raster of interest. The problem is, my raster I'm resampling is a population raster. When I resample, the total ...
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2
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What's correct order of resampling, reprojecting and composing ImageCollection in GEE?
I want to resample, reproject and compose an image collection in python using the GEE API.
My script now is this
adm0 = ee.FeatureCollection("FAO/GAUL/2015/level0");
filter = ee.Filter....
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Anti-alias raster layer by upscaling/ resampling
Recently, I performed a VGA analysis using Depthmap X. I moved the date over using a Mapinfo file (vector) and rasterised the values to the associated pixelsize. The analysis was conducted at a 2m ...
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Should you resample rasters before or after raster calculator operations?
I struggle to understand if rasters should be resampled before or after doing some arithmetic. For example:
Suppose I have a DTM and DSM of an AOI which were produced from the same instrument, but the ...
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0
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186
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Resampling high resolution binary raster
I have a large, high resolution raster of binary data that I need to reproject and resample to align with a lower resolution dataset. Because the original data is binary, I need to aggregate using the ...
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Resampling a raster with R
I'm trying to use the R function resample between two non matching Raster objects. The raster to resample has the following description
hydrogate
class : RasterLayer
dimensions : 1163, 1499, ...
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315
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Resolution of Python GDAL-generated GeoTiff different from plotted image
The Situation
I use the GDAL library to warp geotiffs (subsequently referred to as "rasters") of different resolutions (30m and 500m) to a 100m (subsequently referred to as "default&...
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Method to resample 2d numpy array to a coarser grid and weighted by pixel area in python (analogy to grass r.resmap.stats -w)
What is the optimal method in Python, when I need to resample 2d numpy array (grid) to coarser resolution (weighted by pixel area, the case when the new resolution is not the exact multiple of the ...
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Resampling of Sentinel-1 data to 1km resolution using gdal and snappy modules
I am trying to resample my preprocessed Sentinel-1 data to 1km resolution. I am facing the following issues when I try to do it using snappy and gdal modules.
Using gdal,
Used code:
os.system('...
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415
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Build VRT to merge overlapping rasters always takes max values?
I'm attempting to merge two overlapping rasters from the same source with the same resolution. I would like the overlapping pixels to take the average value of the two overlapping pixels. When I ...
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Resample layer but keep RGB bands (QGIS)
I have an orthophoto from a drone with a spatial resolution of 0.02m and would like to reduce the resolution to 1m. The simplest way of doing this is using the export>save as>and manually fill ...
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Can I resample a raster in R using "max" as function?
With a raster and a reference raster, I'd like to do something like this:
# resample raster to ref_raster to match resolution/origin using max as aggregate
raster = resample(raster, ref_raster, 'max')
...
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Preserve NA areas in resampled raster
I got a raster image with 2m pixel size, there are some areas with value 1 (black) and roads with value NA (white):
It is made from a rasterized shape:
Now I resample my raster to 5 m pixels, the ...
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Resampling nighttime satellite imagery with rasterio (Python)
I am working with a GeoTIFF file from the Earth Observation Group (3rd download on this page). Once extracted, the file is too large (5.6gb) to do much with on my laptop - so I am trying to downsample ...
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296
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Downsampling GeoTIFF in QGIS using GRASS
I need to downsample a GeoTIFF image. I have been trying to test this using a simple example like using the following r.samp.res dialog.
(I know I could also export the TIF file directly following ...
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234
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How does Google Earth Engine deal with scaling up/down categorical data?
I read the docs on Resampling and Reducing Resolution and Projections. I sort of get that the scale/projection is determined by the final outcome but I still don't get how categorical data are handled....
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Actual area from polygons is either under- or overestimated when extracting raster values - any solutions?
I am trying to use ModelBuilder to iterate through sets of polygons to overlay on top of two rasters and extract the total area of each value from each raster, but am having issues with the estimated ...
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2
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263
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Differencing two rasters with very different resolutions (QGIS 3.20.3)
I am having a problem with analysing two rasters with 2 significantly different resolutions.
Background on the two rasters:
DEM is the ALOS_30m DEM which is in the WGS_84 format. Merged together ...
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0
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644
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Generation of snow cover area time series in GEE using MODIS Snow Cover product
My aim is to resample MOD10A1/MYD10A1 to the same scale as that of MOD11A1/MYD11A1, mask the image collection to obtain the best pixels, and finally to obtain the time series plot of the total area ...
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