Questions tagged [resampling]

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

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40
votes
4answers
58k views

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?
20
votes
2answers
27k views

How to resample GeoTIFF images to the same resolution?

I have two geotiff images that I would like to resample the same resolution. If I use ArcGIS this would be easy to do. But using QGIS I don't know how to do this. Some help will be very appreciate. ...
46
votes
3answers
15k views

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 ...
6
votes
3answers
9k 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?
10
votes
2answers
2k views

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 ...
16
votes
1answer
3k views

When dealing with rasters of varying resolutions should one resample to the highest or lowest resolution?

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 ...
23
votes
3answers
6k views

What resampling technique should be used when projecting aerial photos?

I'm doing some time-intensive projecting of aerial photos, and I'm curious - what resampling technique is best to use on aerial photos? In ArcMap, my options are NEAREST, BILINEAR, CUBIC, and MAJORITY....
5
votes
1answer
3k views

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 ...
3
votes
2answers
709 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 ...
7
votes
1answer
2k views

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?
1
vote
2answers
3k views

Convert Raster Resolution in arcGIS

I have to analyze 8 raster layers, 5 of them are 0.5 degree resolution and the other three are 0.05 degree resolution. Firstly, should I resample the 5 to finer resolution (0.05 degree) and if ...
4
votes
1answer
4k 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 ...
2
votes
1answer
515 views

What resampling method is used in gdal_merge?

I am using the gdal_merge python script to merge rasters that have slightly different, though similar, input resolutions. The documentation advertises that it can handle different resolutions, and in ...
8
votes
1answer
277 views

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 ...
3
votes
1answer
2k 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 ...
3
votes
1answer
780 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 ...
6
votes
2answers
187 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 ...
4
votes
1answer
1k views

Resampling method used in QGIS Raster save as?

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 ...
4
votes
1answer
1k 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 ...
4
votes
1answer
598 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 ...
3
votes
1answer
1k views

Converting worldclim data to 30m resolution

I know that resampling from coarse resolution to fine resolution is bad. Effectively you are making up data. However, if the study area is small are there any other options? Worldclim comes at around ...
3
votes
0answers
244 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-...
1
vote
2answers
540 views

Resampling raster based on mask raster?

I want to resample rasters of e.g. 2 m resolution to the same raster cell size and projection of an existing raster (25 m). However I cannot really find answers how to do it properly. I managed to ...