Questions tagged [resampling]

To alter the frequency of sampled data points in continuous data.

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Resample using Rasterio with Resampling.sum method

I want to resample Geotiff image using Rasterio with Resampling.sum I have the following code, however, it returns, ResamplingAlgorithmError: <Resampling.sum: 13> can be used for warp ...
0 votes
3 answers
645 views

Rasterio reading outshape resample does not give correct array

I have a population grid and want to decrease the resolution by a factor 2. I would like to get a raster that has 2 times less rows and columns, a resolution that is 2 times as large as the original ...
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13 views

ENVI 5.6.2 HSV problem

I've used ENVI a lot in the past, but am a bit rusty. I have never ran into this problem and can't find anything online about it. I'm trying to do HSV sharpening with 3 band multispectral data and a ...
1 vote
2 answers
1k views

Cell size in Mosaic to New Raster versus Resample cell size

I have several TIF 2 meter LIDAR DEM files (100+) that I am merging into a single raster and then creating 4m, 6m, 10m, and 30m DEM raster variants. I would normally just use the Mosaic to New ...
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0 answers
34 views

How do I resample a raster layer over another layer in QGIS 3.x?

I have 2 raster layers (the full same area): Layer 1: 30 m resolution, coordinate system is EPSG:32643, layer size is 7406x6801; Layer 2: 10 m resolution, coordinate system is WGS 84, layer size is ...
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1 answer
326 views

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 ...
0 votes
1 answer
1k views

Positional argument error using rasterio to reduce raster pixel size

I'm new with rasterio and I need to reduce the pixel size of a GeoTiff. Using the code below def resample(input_raster: str, output_raster: str = None): upscale_factor = 2 with rasterio.open(...
3 votes
2 answers
316 views

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 ...
2 votes
1 answer
180 views

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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0 answers
95 views

Resample Sentinel-2 bands from 20m to 10m using GEE code outside of GEE

I want to resample the 20 meters bands of Sentinel-2 to 10 meters. I found this piece of code in GEE and after trying it out, this is what I would like to do to my Sentinel images but outside of GEE. ...
0 votes
1 answer
498 views

GEE: resampling MODIS LST from 1km to 200km produces gradient

I am trying to resample raster from 1km resolution to 200m using this code: var august = ee.ImageCollection(landsat) .filterDate('2019-08-01', '2019-08-30') .filterBounds(geometry); //Mean ...
1 vote
1 answer
305 views

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 ...
7 votes
1 answer
1k views

Can extracting raster values work in polygons' CRS without raster resampling?

I am trying to extract raster values using polygon layer with different CRS. Raster is in WGS84 (EPSG:4326) and the polygons in UTM (EPSG:23031). 1. If I want to work in the projection of the ...
3 votes
1 answer
162 views

Generating DEM that gives realistic contour

I am quite new QGIS user. I have point data from the field and I generated DEM and contour. However, the contours are a bit unrealistic. I have attached the image. The green contour is the contour ...
0 votes
1 answer
278 views

Resample of mean of ImageCollection to higher resolution

I want to resample the mean of 48 images of GPM with 10000m to MODIS in GEE. My code works perfectly for one image but the result for the mean or median of 48 images (or any number) does not correct. ...
1 vote
1 answer
284 views

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 ...
1 vote
1 answer
402 views

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) ...
0 votes
1 answer
343 views

Sampling raster data and classifying the pixels

I'm completely new to python usage in GIS. I'm working with Sentinel images and want to sample the pixels of raster file only in the places which are represented by the geometry of the truth data ...
0 votes
0 answers
64 views

Problems with the SAGA Next Gen Tool "Resampling Filter"

When running the Saga Next Gen tool "Resampling-Filter" I get the error message: failed: could not find a suitable import driver**" and "**[Import Raster] Execution failed (less ...
3 votes
1 answer
362 views

Resampling with Python console (QGIS): number of parameters

I am trying to resample two raster layers with Python console in QGIS with this code: outputs_0=Processing.runAlgorithm("saga:resampling", 'G:/DOCTORAT/2014/Incendis/Dades/LST/LST_TERRA/Tiff/...
0 votes
1 answer
93 views

QGIS - keep square pixels in resampling

I have a raster file (asc) with a resolution of about 10m, square pixels and an extent of X: 15929 Y: 16159. I am trying to resample this to a larger resolution (tried 20 and 30m). However, the output ...
2 votes
1 answer
88 views

QGIS simple downsample of a raster

I'd like to downsample a DEM raster from 2m per pixel to 8m. I've tried using SAGA Multilevel B-spline interpolation (from raster) as suggested here, but though that results in an 8m resolution it ...
0 votes
0 answers
38 views

How to assign a value to a set of 25 identical pixels in a raster layer?

I am using ArcGIS Pro 3.1 I would like to create a new raster layer from an existing raster composed of 4 possible discrete values (MIN=0, MAX=4, VAL=0,1,2,3,4). This existing raster illustrate ...
0 votes
1 answer
56 views

R: Resample raster layer according to a polygon grid

I have a reference polygon grid and several raster layers with varying resolutions. I need to resample raster payers so that the cell sizes and locations of the new rasters match the cell sizes and ...
0 votes
0 answers
158 views

Optimize the resampling and projection of multiple NetCDF files in R using terra

I have a set of 35 NetCDF files (continental scale), each containing 365 daily layers of climate data with a resolution of 5 km, s. I need to do two main tasks: Subset, s_sub, these files based on a ...
8 votes
2 answers
6k views

Aligning two rasters of same resolution perfectly on top of each other in QGIS

I have two rasters, that I managed to make in the same resolution using the 'Raster tools --> Resampling' tool by SAGA. The pixel sizes are exactly the same, however the new resampled raster, in ...
1 vote
1 answer
47 views

QGIS Raster resampling without label changes

I am working on raster data that which is in a 5x5 meter resolution. I need to resample this to a 25x25 meter resolution. I have used resample.stats which works, but changes the label numbers into one ...
2 votes
1 answer
393 views

Differences in raster extents in gdalinfo, SAGA & QGIS after resampling [closed]

I recently resampled a raster file using SAGA's Resampling module. The aim was to widen the extent of the new raster to two decimal places, where the original raster has three decimal places. The ...
0 votes
0 answers
93 views

Resampling Sentinel-2 images

I want to change Band-11 (SWIR Bands) of Sentinel-2 to 10m resolution. I found resampling process used for it. Doesn't it affect the spectral characteristics for processing further???
0 votes
0 answers
98 views

In GEE: Calculating area in WGS84 masking out regions with layers in different resolutions

I am trying to calculate the number of affected people by flooding, but only those who are living in urban areas. So essentially, I take the WorldPop dataset and overlay it with flood extent and land ...
0 votes
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149 views

Image (Error) Image.reduceResolution: The input to reduceResolution does not have a valid default projection. Use setDefaultProjection() first

I would like to aggregate the 30m images to 990m on average through reduceResolution, but he shows me to add the default coordinate system, but I have already added it and this still happens. Below is ...
3 votes
0 answers
473 views

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 ...
5 votes
1 answer
551 views

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 ...
2 votes
1 answer
72 views

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+...
1 vote
1 answer
170 views

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 ...
3 votes
1 answer
445 views

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&...
0 votes
1 answer
84 views

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 ...
0 votes
0 answers
14 views

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, ...
0 votes
1 answer
283 views

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()...
19 votes
1 answer
7k views

Resampling to highest or lowest resolution when dealing with rasters of varying resolutions

I'm looking for recommendations on best practices for dealing with raster data layers with different resolutions and projections. The advice I've been given is to always resample to the layer with the ...
1 vote
1 answer
136 views

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/ > ...
0 votes
0 answers
59 views

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 ...
1 vote
2 answers
544 views

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 ...
20 votes
2 answers
9k views

Creating an in memory rasterio Dataset from numpy array

I am reading in a raster using rasterio, and then upsampling the raster as per the example in the documentation: def upsample_raster(raster): return raster.read( out_shape=(raster.height *...
1 vote
2 answers
464 views

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 ...
1 vote
0 answers
95 views

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 ...
2 votes
0 answers
150 views

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 ...
0 votes
1 answer
443 views

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 ...
2 votes
0 answers
110 views

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( ...
0 votes
2 answers
2k views

Bilinear resampling with GDAL leaves holes

I'm attempting to down-sample a raster (resampling to a coarser/ larger pixel size) with continuous, floating-point values. I generally use bilinear resampling for the up-sampling case (resampling to ...

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