Questions tagged [resampling]

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

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What is Lanczos resampling useful for in a spatial context?

GDAL includes a resampling method beyond the normal mix of nearest neighbor, bilinear, cubic and splines: "Lanczos windowed sinc resampling". I understand that its a convolution filter, but unlike ...
scw's user avatar
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45 votes
4 answers
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Deciding what interpolation method to use for resampling raster data?

Are there hard and fast rules about which interpolation methods are suited to each kind of raster data?
ninesided's user avatar
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29 votes
4 answers
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Resampling GeoTIFF images to same resolution using QGIS

I have two geotiff images that I would like to resample the same resolution. If I use ArcGIS Desktop this is easy to do but how do I do this using QGIS?
Gil Gonçalves's user avatar
26 votes
3 answers
9k views

What resampling technique should be used when projecting aerial photos?

I'm doing some time-intensive projecting of aerial photos. What resampling technique is best to use on aerial photos? In ArcMap, my options are NEAREST, BILINEAR, CUBIC, and MAJORITY. Nearest Neighbor ...
Tanner's user avatar
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20 votes
2 answers
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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 *...
Renier Botha's user avatar
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 ...
Matt SM's user avatar
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13 votes
1 answer
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Understanding raster symbology settings

I am trying to understand how to use the symbology options for raster layers in QGIS, particularly the Resampling options, but the official documentation only mentions the setting very briefly and ...
Nathan's user avatar
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12 votes
1 answer
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What resampling technique should be used to reproject an altitude raster?

Does anyone know whether I should choose: nearest, bilinear, cubic or majority when projecting the WorldClim altitude raster layer?
skid's user avatar
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10 votes
2 answers
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Resample binary raster to give *proportion* within new cell window

I would like to go from a binary raster of forest/non-forest at 30m resolution to a raster at 240m resolution with the value of each cell being the proportion of that cell forested - i.e. the data ...
stuckGIS's user avatar
  • 175
9 votes
1 answer
3k views

EarthEngine: average/reduce a raster at resolution of coarser raster?

I want to average a 30m raster at the resolution of a 1000m one. Specifically, I want to computer, for each Daymet raster cell, the percentage of cultivated land from the 30m CDL. How can I do that ...
Matifou's user avatar
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8 votes
2 answers
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Up-sampling (increasing resolution) raster image using GDAL?

I have a single-band geo-referenced raster image (a DEM) and my goal is to increase the number of pixels in each dimension (x and y) by 3. So given an initial resolution of 1200 * 1200 pixels, I want ...
Basile's user avatar
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8 votes
1 answer
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Why do "stripes" appear on raster?

I am reprojecting a SRTM 3 arc-second raster file from WGS84 geographic coordinate system, to projected coordinate system which is using Azimuthal Equidistant projection: gdalwarp -s_srs EPSG:4326 -...
marco's user avatar
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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 ...
Andrea Rey's user avatar
7 votes
1 answer
6k views

Pros and Cons of using Bilinear Interpolation and Cubic Convolution when dealing with DEMs? [duplicate]

I am currently processing a handful of DEMs (derived from LiDAR data). I have a conceptual question, when choosing a Resampling Technique what are the pros and cons of using Bilinear Interpolation and ...
MoreMeowbell's user avatar
7 votes
2 answers
10k views

Should resampling/downsampling a raster (using Rasterio) cause the coordinates to change?

I was able to successfully downsample a raster file, after getting Stack Exchange help. I loaded the new downsampled file into QGIS along with the original file, to check that things went well. The ...
krishnab's user avatar
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7 votes
2 answers
1k views

How does oversampling work in WMTS layers?

(This question arises as a sub-topic of the answer provided here.) In the symbology options for a raster layer in QGIS, there is a setting called "Oversampling" (see image below). How does this ...
Nathan's user avatar
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7 votes
1 answer
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Resampling method used in QGIS Raster save as? [duplicate]

I have what seems like a simple question, but I haven't been able to find the answer in the QGIS documentation. I have a raster that is 250 m resolution, and I want to resample it to 1000 m ...
Sam Zipper's user avatar
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 ...
Tomas's user avatar
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6 votes
3 answers
11k views

Resizing image resolution in ArcGIS Desktop?

I have NDVI images (250 m) and Soil map (1000 m). How can I change the resolution from 1000 m to 250 m, so I can compare/work with them?
user3063's user avatar
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6 votes
1 answer
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Best Resampling Method for DEM reprojection in QGis

I need to reproject a DEM (raster file) in order to have the same CRS as all my other project data - I have different shapefiles for the same DEM's location but they have a different CRS. Which ...
Rui Prata's user avatar
  • 119
6 votes
1 answer
1k views

Changing image size in ArcGIS Desktop?

I did interpolation operation on temperature and precipitation data. Output image size is 3300 (col) and 2550 (row). I have some NDVI images with size of 15456 (col) and 5074 (row). Generally, I ...
Lusa's user avatar
  • 101
6 votes
2 answers
4k views

How to resample a raster layer to match a specific raster layer's cell size?

I would like to resample the cell size of a GeoTIFF raster layer with dimensions equal to the reference file (a Sentinel-2 B12 band with 20 m resolution to 10 m resolution). I use the following code ...
DanielKovacs's user avatar
6 votes
1 answer
784 views

Is the bilinear resampling technique appropriate for the projection of ASTER data?

I need to project some ASTER data from a geographic coordinate system to a projected one. I have read online that the cubic resampling technique is the most appropriate for this purpose. However, ...
jc22's user avatar
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5 votes
1 answer
9k views

Resampling a raster from python without using gdalwarp

I'm trying to resample a GeoTIFF file to match another raster layer using python GDAL package. Most of the ways I found online is to use gdalwarp resample data from the command line. Is there a way to ...
MaxG's user avatar
  • 505
5 votes
2 answers
2k views

Changing pixel size in 'asc' file using QGIS?

I have soil data and BioClim data from Australia soil data: rows 2200 columns 1400 pixel size 0.0025, -0.0025 255 BioClim data: rows 660 columsn 420 pixel size 0.00833333, -0.00833333 I am ...
SteveResearch's user avatar
5 votes
2 answers
660 views

Smoothing or resampling DEM to find steep roads?

I am trying to find sections of road with steep gradients. My process is: pull a linestring from Openstreetmap data resample it to create a point every 10 metres look up the height data for each ...
user1331131's user avatar
5 votes
1 answer
539 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 ...
Babel's user avatar
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5 votes
1 answer
2k views

Reproject masked array with rasterio

Is there a way to preserve the mask of a numpy array when reprojecting it with rasterio? See the reproducible example with real data below: import os import tempfile import rasterio from rasterio....
Loïc Dutrieux's user avatar
5 votes
2 answers
5k views

convert lat/lng to pixel and vice versa

This had been asked previously on Stack Overflow. I've tried different methods/formulas but results are not correct. 40.764296,-73.97302 should result into 930,3590 pixel on map image. I've Manhattan ...
Tariq Mahmood's user avatar
5 votes
0 answers
644 views

Resample a raster to the grid of another unaligned raster using GDAL/pktools

Is there a way to resample a raster to the grid of another raster using Bash utilities (GDAL or pktools), if both of the rasters do not necessarily have their origins aligned (and without an ...
GreatEmerald's user avatar
5 votes
0 answers
410 views

What is the kernel width of the gdalwarp resampling methods?

gdalwarp provides 7 resampling methods. How many neighborhood pixels do contribute to upsampling respectively downsampling? I will try to guess. Please correct, if values are wrong: Upsampling: ...
kking009's user avatar
  • 118
4 votes
1 answer
2k views

Squaring pixels of GeoTIFF using GDAL

I have a GeoTiff that has been supplied to me with non square pixels (I suspect due to reprojection to lat lon at some point). However the next step in my processing chain requires a Arc ASCII grid as ...
Ian Turton's user avatar
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4 votes
1 answer
2k views

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/...
hmnoidk's user avatar
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4 votes
1 answer
125 views

What proportion of the 240m area sensed by MODIS must be forest before it is defined as forest?

MOD12 is a MODIS product at 240m resolution. Landsat produces 30m resolution products, which I resampled to 240m resulting in a raster of proportion forest cover in each 240m pixel (based on the mean ...
gisol's user avatar
  • 540
4 votes
1 answer
5k views

Using shapely interpolate to evenly re-sample points on a linestring geodataframe at specified interval

I have a GeoPandas LineString GeoDataFrame. I am trying to evenly interpolate the spacing of the nodes that make up each line, with a couple constraints: keep endpoints unchanged, and specify maximum ...
a11's user avatar
  • 940
4 votes
1 answer
560 views

Vector to Raster for Smoothing purposes using ArcGIS Desktop?

I have a vector file that represents transit scores by Census Tract (CT) of a city. It shows harsh boundaries where one CT has great access to transit and right beside that CT is one that has ...
hhart's user avatar
  • 464
4 votes
1 answer
2k views

Gdal/QGIS resampling asc file

I have a DEM (.asc) file with a resolution of 1000 meters per pixel. Therefore the file has a lot of columns and rows. I would like to chance the resolution per pixel from 1000 to 3000 meters per ...
Duddel's user avatar
  • 375
4 votes
1 answer
3k views

1m cell size equivalent value in decimal degree

I'm doing re-sampling pixel size in ERDAS 2014,I'm using input image(Indian terrain) in GCS_WGS_84 projection. Now I have to keep out put cell size as 1m,what is the 1m equvivalent value in Decimal ...
Satya Chandra's user avatar
4 votes
2 answers
3k views

Resample, ArcGIS: How do I avoid resample taking into acount NoData values?

I am trying to Resample a raster dataset to match the resolution of another dataset. I have fine resolution data on small islands (surrounded by NoData in the sea). When I re-sample the data to a ...
David Cooper's user avatar
4 votes
1 answer
487 views

Converting dataset between coordinate systems

I'm working with NOAA's PRECipitation REConstruction over Land dataset, and am looking for an efficient way to sample the data by pixels on NASA's MODIS grid, using open source tools. The PRECL data ...
Sam Ritchie's user avatar
4 votes
1 answer
469 views

How to resample QgsRasterLayer in QGIS 3?

I am generating png images of concentration maps, resulting from air quality modelling. Resulting files are croped and coverted to tiff files and than loaded into QGIS in Python: rlayer = ...
Marcin Kawka's user avatar
4 votes
2 answers
557 views

"Downsample" a dense grouping of points onto a sparse grid

I have a SpatialPointsDataFrame with thousands of datapoints in a relatively small geographic area. The points are grouped around regions of physical measurements and are hence irregularly spaced: ...
nivek's user avatar
  • 161
4 votes
1 answer
2k views

Rasters lose quality when Georeferencing using ArcGIS for Desktop?

I've started to have a problem when georeferencing some rasters in ArcGIS 10.2.2 where the image appears in much lower quality with false colors and higher contrast. The images appearing in ArcGIS do ...
MMR's user avatar
  • 41
4 votes
0 answers
1k views

Using max as resampling method with gdal_translate?

My Issue According to the docs it appears that gdalwarp has many more resampling methods than gdal_translate. Can anybody explain why the resampling methods can't be used with both functions? ...
Braden Roseborough's user avatar
4 votes
0 answers
375 views

Reprojecting a population raster from LAEA to lonlat

I have a population density raster from the EEA which is based on the CORINE land cover 2000 data. http://www.eea.europa.eu/data-and-maps/data/population-density-disaggregated-with-corine-land-cover-...
telegott's user avatar
  • 165
3 votes
2 answers
593 views

Is Satellite Image Continuous Data?

I have a satellite image of one region. I perform interpolation on this image. However, I am not sure Satellite Image is continuous or discrete data.
Sun's user avatar
  • 113
3 votes
2 answers
9k views

How to resample a raster to higher resolution in QGIS?

I'm fitting a SDM using R. A requirement is that all environmental predictor layers have the same extent, origin and resolution. I have high resolution bathymetry data (25m) that I will resample to ...
DaveS's user avatar
  • 61
3 votes
1 answer
4k views

Using xarray to resample and merge two datasets

I have one dataset of satellite based solar induced fluorescence (SIF) and one of modeled precipitation. I want to compare precipitation to SIF on a per pixel basis in my study area. My two datasets ...
clifgray's user avatar
  • 409
3 votes
1 answer
435 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&...
winnewoerp's user avatar
  • 1,508
3 votes
1 answer
1k views

Creating RGB composite using GDAL: resampling?

I want to use gdal_merge.py for creating rgb composite from 3 bands with the same qualities (resolution, crs..), but here I found that gdal_merge.py is using nearest neighbor resampling method. Is ...
J.Coo's user avatar
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