Questions tagged [resampling]

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

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6
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1answer
294 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 -...
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1answer
911 views

Resampling a raster file with GDAL C#

Is it possible to resample the raster by using GDAL C# binaries, in a way that every other cell in a row and column is removed? Basically a replication of this GDAL command: gdal_translate -outsize ...
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0answers
362 views

Resampling netcdf file?

What is the best way to change the cell size of a netcdf file, keeping it as netcdf? I have looked into ArcGIS and GDAL and have not found anything yet. I prefer to use python if a solution is ...
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0answers
206 views

Is it valid to resample a raster from 1m to 3 feet?

I know that in general it is not a good idea to up-sample. I am curious if it would still be be a "bad idea" with a minor change like this from 1m resolution to 3 feet? Going to 3 feet would not ...
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0answers
286 views

gdalwarp won't run with “cubic” resampling method [closed]

I am having an issue with running the gdalwarp command from command prompt. Basically I have a raster WGS84 file, which I would like to reproject to spatial reference which is using the Azimuthal ...
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0answers
353 views

Flipped (Y-axis) Raster from point cloud

I have been working on a project where I need to create rasters from irregularly spaced point clouds. I am resampling my point clouds to a regular 0.25 cm grid using a nearest neighbor method ...
2
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0answers
280 views

Possible to resample tifs in numpy array? [closed]

I need to resample a large number of tif files. Is it possible to put the list of rasters in a numpy array and resample the array? I'm thinking this would be faster than looping through the list, but ...
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0answers
748 views

Change pixel size of 30m for 23.5m in QGIS [duplicate]

I need to change pixel size in raster file file with Pixel Size = (28.086057277202915,-28.086057277202915) using Qgis for Pixel Size = (23.951601289061028,-23.952379920305706) what kind of function I ...
5
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2answers
4k 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 ...
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0answers
868 views

Efficient way to resample, crop, and mask a raster image using R

Does anyone know an efficient way to resample an image? I am currently trying to crop a large image and clip two regions from a shapefile. From this clipped image, I would like to increase the pixel ...
5
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2answers
903 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 ...
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1answer
203 views

How does Resampling raster work at corner cells?

This may seem quite a simple question for which I couldn't find a satisfactory answer. I have been trying to understand how resampling of raster work with ArcGIS 10.3, in both cases of refining and ...
2
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1answer
182 views

Resampling gives higher MEAN when using zonal statistics

I am using ArcGIS 10.1 for Desktop. I have a value raster and a polygon feature in GCS coordinates. My raster resolution is 0.5 decimal degrees which is much larger than the size of my polygons. My ...
2
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2answers
2k 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....
2
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1answer
79 views

Can I use areal mean pixel value in raster for input to Extract Values to Point tool

I have a dataset consisting of a point vector file (plant leaf area) overlaid and georeferenced to a raster file (soil moisture) that I want to use as inputs to the Extract Values To Point Tool in ...
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2answers
1k views

Resampling DEM using gdal in python?

Using gdal I want to resample (in this case, oversample) a DEM. The only thing that should change is the pixel spacing, so I want to interpolate in between the values that I currently have. For this I ...
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1answer
464 views

Resampling 30 m NDVI to 5 m in ArcGIS [duplicate]

Is there any easy way to resample 30 meter NDVI from Landsat 8 images to 5 metres? I use raster to point and the interpolation of point to raster using Kriging method. I know that it may not be a ...
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0answers
466 views

Why does gdalwarp's cubicspline method expand into nodata areas?

The image below shows part of a peninsula on the Australian island of Tasmania. The black pixels are 9" climate data with GDA94 (EPSG:4283) SRS, projected by QGIS on the fly to Australian Albers (EPSG:...
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1answer
342 views

How does majority algorithm works in ArcGIS

I'm trying to understand how does the majority resampling works in ArcGIS, they write that "The MAJORITY option, which performs a majority algorithm, determines the new value of the cell based on the ...
2
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1answer
636 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 ...
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0answers
528 views

When subtracting two raster with different cell sizes using raster math, what value is used for smaller cells?

After reading the answer to a similar question (What will happen if we subtract two raster with different cell size using Raster Calculator?), I am still left with a question. When the raster with ...
3
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1answer
727 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, ...
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1answer
301 views

Looping inside r.mapcalc in GRASS GIS

I have a Land Cover classification map that I created from 2m resolution multispectral imagery and I am trying to downsample the results to a 20m resolution class map. The climate in question is ...
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2answers
314 views

Re-sample raster to acre grid using ArcGIS Desktop or R? [closed]

I have a 1m classified landcover raster layer that consists of values 1-4 representing various land covers. I need to resample this layer to an acre grid. Each acre in the resultant grid should ...
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0answers
222 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
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1answer
430 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
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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
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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 ...
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1answer
324 views

Saga:processing resample extent in python editor QGIS

I would like to resample many geotiff layers to another geotiff layer's extent and pixel size. For this I would like to use the QGIS python console (editor). When I run my script it raises the ...
0
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1answer
356 views

Work order: project then resample, or resample then project

I'm working with 10m DEMs in northern New York, along the Canadian border (in ArcGIS 10.2). To complete a regional elevation map (and eventually slope, flow, etc.), I need to also include a portion of ...
3
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0answers
261 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-...
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2answers
664 views

Divide two rasters with different cell sizes using ArcGIS for Desktop?

I've got two rasters of the exact same location (So every pixel in one raster is equivalent to the pixel in the other raster). Raster A has a resolution of 6m per pixel. Raster B has a resolution of ...
5
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2answers
490 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 ...
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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 ...
8
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1answer
3k 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?
4
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1answer
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 ...
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 ...
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1answer
59 views

The resampled image has many NaN values and does not cover the complete area of the input raster [closed]

when I resample an image of 20m to 240m resolution, the resampled image does not cover the whole area of the input image and does the resampling for some pixels in which I get many NaN values. How can ...
4
votes
1answer
363 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, ...
2
votes
1answer
361 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
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0answers
126 views

Align & Sum Grids in Python

I have two grids. One, call it A, is 4320x2160 cells and spans the whole globe. The other, call it B is 8640x3432 and spans the circumference of the globe, but is clipped toward mid-latitudes. Both ...
3
votes
1answer
292 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/...
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1answer
3k views

Best Resampling Method for DEM reprojection in QGis

I need to reproject a DEM (aster file) in order to have the same CRS as all my other project data - I have different SHP for the same DEM's location but they have a different CRS. Which resampling ...
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 ...
2
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0answers
142 views

Is it feasible to reclassify a raster which has been resampled/smoothed for display purposes?

Background: I have a Google Earth KMZ file which shows ground movements after an earthquake, arranged into discrete classes: From the KMZ file I'm able to download the original PNG images, which are ...
16
votes
1answer
4k 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 ...
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2answers
2k views

How to resample polygon vertices so that they are evenly spaced in Arc 10

I have digitized the outline of many river channels (by both manually picking points and using streaming mode), but now I need the vertices to be evenly spaced (for input to another program). I tried ...
21
votes
2answers
33k views

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. ...
5
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0answers
572 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 ...
2
votes
1answer
314 views

Lack of Options in Gdal Tool “Build Overviews” QGis

I am using QGis 1.8 and I want to build overviews (pyramids) for satellite imagery using the Gdal Tool. I would like to use the resampling method "cubic convolution", but the option doesn't exist ...