Questions tagged [resampling]

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

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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 ...
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?
23
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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....
20
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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. ...
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 ...
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 ...
8
votes
1answer
275 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 ...
7
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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?
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?
6
votes
1answer
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 ...
6
votes
2answers
186 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 ...
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 ...
5
votes
2answers
456 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 ...
5
votes
1answer
96 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 ...
5
votes
2answers
3k 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 ...
5
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0answers
396 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 ...
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 ...
4
votes
1answer
227 views

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 -...
4
votes
1answer
118 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 ...
4
votes
1answer
503 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 ...
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
350 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, ...
4
votes
2answers
2k 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 ...
4
votes
1answer
471 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 ...
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
2answers
289 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: ...
4
votes
1answer
595 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
776 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 ...
3
votes
2answers
5k 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 ...
3
votes
1answer
477 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 ...
3
votes
2answers
706 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 ...
3
votes
1answer
1k views

Choosing Point to Raster vs Feature to Raster in ArcGIS for Desktop?

I am converting point vector data to a raster dataset using nearest neighbor. I am using arcgis 10.2. The first step is to use the conversion toolbox, but there are two possible options: Point to ...
3
votes
1answer
977 views

how to square the pixels of a GeoTiff

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 ...
3
votes
1answer
320 views

Is GeoServer Image Pyramid upscaling?

I have an Image Pyramid in GeoServer 2.2 RC3 (not the latests - I know, but I have other pyramids working here). The total size is around 1TB and file size is around 1-2GB for each GeoTIFF. When ...
3
votes
1answer
403 views

Reducing number of points, keeping most recent data within given distance, using QGIS?

I have a HUGE dataset of points that were collected along a route. The data may change daily, and the most recent data is the most important. What I would like to do is take only 1 point from a given ...
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
776 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....
3
votes
1answer
650 views

ArcGIS resampling rasters by maximum pixel value?

I need to resample a binary image of linear features like roads, rivers to a coarser resolution, conceptually combining multiple pixels into a single one. 1 indicates presence of the linear feature, ...
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
1answer
48 views

GeoServer v2.9.1 re-sampling errors with GetCoverage request

App I'm using Openlayers3 and GeoServer 2.9.1 to create an application allowing users to draw an aoi then download it as raw data subsets (geotiff) of a Canada wide data set (also geotiff). I'm using ...
3
votes
1answer
285 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/2012/...
3
votes
1answer
310 views

Differences in raster extents in gdalinfo, SAGA & Quantum after resampling

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 ...
3
votes
1answer
579 views

Raster format with rotated cells - no resampling

Is there any way to rotate a raster w/o resampling? I am aware that rasters are always 90 deg perpendicular grids, but is there any file format or methodology that allows for a diagonal raster - one ...
3
votes
0answers
767 views

Changing Raster Resolution to match other Raster in QGIS

I have a raster layer of 0.125 degree resolution and another raster layer of 0.0833 degree resolution. Both the raster layers are to be overlapped. So, I want to change the resolution of 0.0833 ...
3
votes
0answers
180 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: ...
3
votes
0answers
243 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-...
2
votes
1answer
1k views

How gdal_rasterize works - how it interpolates / resample values?

I have huge number of points saved as shapefile. I created an empty raster file with low spatial resolution. Next, I applied gdal_rasterize on mentioned .shp and used low resolution raster as ...
2
votes
1answer
308 views

Better way to combine 2 rasters

I have two raster layers: One with 56 m resolution and the other has 30 m resolution. Usually, I just use the 'Combine' command in ArcGIS to combine them, getting a single value for each unique ...
2
votes
2answers
426 views

Is it Possible to Resize the Pixels

I classified this image in ArcGIS 10.3, but my Professor said the pixels are big and I should make it smaller. This is my problem: is there any tool that can use to make the picture grains finer. Or ...
2
votes
2answers
1k views

Resample not changing the cell size

I am trying to use the Resample tool in Spatial Analyst to go from a 1kmx1km grid to a 500mx500m grid for increased resolution of my land use data. My cell size is 0.008, and I want a 0.004 cell size....