Questions tagged [smoothing]

smoothing is a generalization process that removes any extreme values in a line string or surface

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Reshaping existing features with freehand using ArcMap [duplicate]

I need reshape polygons have sharp degrees like red line in Image. I can't use smoothing because the existing polygons already overlap with another feature and I am also want to correct the location ...
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How to smooth interior polygons of one shapefile

I have a shapefile that includes the boundary of a field plus many interior polygons that represent levels of NDVI - we'll say High, Medium, and Low. The larger areas have jagged, irregular edges. ...
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Rasterbrick NDVI smoothing

I've scoured the internet for an answer to this, but the methods I've read up on either aren't applicable or just aren't working. I'm currently looking at the NDVI timeseries over 19 years worth of ...
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Aggregate / Simplify / Buffer polygons ArcGIS

[ArcGIS Pro 2.5 / Windows 8.1 Enterprise] I'm trying to follow some instruction to reconstruct a polygon layer for the current year. However, I cannot solve a step in these instructions, namely "...
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How to smooth discrete raster data with GDAL in C++?

I am using GDAL in C++ for upsampling land-cover raster data. When upsampling, I would like to smooth out the edges, so that I do not get aliased stairs but nice diagonal lines. Essentially, the "...
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23 views

Turn disjoint polygons into tessellation

I have a set of points that have labels. These labels represent geographies; however, some of the labels are wrong. Like in the picture below So after running some analysis, I end up with a set of ...
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72 views

Smooth contour lines/correctly extract contour lines from a DEM in QGIS

I have a DEM obtained as a result of the interpolation of elevation points TIN Interpolatin: I extracted the contour lines in QGIS and the result is this: After I tried to apply the Line Smoothing ...
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1answer
50 views

A simple way to merge lines separated by a space in QGIS

In QGIS after creating contour lines by extracting them from a DEM (Extraction > Contour) and smoothing them (Line Smoothing) I noticed this situation: In order to smooth out the corners ...
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Which resolution is appropriate for resampling a raster in a specific CRS in QGIS 3.6? [closed]

I'm trying to resample a raster file to obtain smooth interpolated levels in EPSG:3120 - Pulkovo 1942(58) / Poland zone I projection. (following the steps in this answer) 1. Using the raster ...
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2answers
547 views

Making elevation contours of raster smoother using QGIS

I am using QGIS 3.6. I have raster of Europe map which I want to make a colored relief model. After duplicating the layer, used hillshade on backward layer and colored the upper layer interpolation >...
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Impact of r.neighbor window size on raster values

I have the residuals of a detrended DEM of a glacier surface in QGIS. With these residuals I have used QGIS' r.neighbor standard deviation over a range of neighbourhood sizes (window sizes) as a proxy ...
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1answer
45 views

Seeking algorithm that can re-locate vertices on linestring so that line does not intersect land polygons

I'm currently working with GPS data gathered from boats. The data has low temporal resolution (every 5 minutes) which causes the linestrings that display the boat's trajectory to be jagged. An example ...
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1answer
57 views

Setting correct start and end time series for Savitzky-Golay in R

I am trying to smoothen my raster stack using Savitzky-Golay method. I am following the workaround from HERE but my problem is setting start and end of my time-series raster. My series of images were ...
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1answer
62 views

Raster smoothing - assigning each raster the average value of its neighbors

I have a raster world map of population densities at a resolution of 30 arc seconds. For each raster, I want to find out the average density of neighbors within a certain distance (e.g. 0.1 degrees). ...
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1answer
136 views

How can I smooth LineString coordinates with 1D Gaussian Filter?

I'm trying to smooth a LineString through 1D Gaussian Smoothing and I'm having a doubt on the steps required to implement it, regardless of programming language. I couldn't find by myself anything ...
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1answer
774 views

Smoothing polygons in QGIS? [duplicate]

I vectorised an image and all my polygons have extremely jagged edges. What is the best way to smooth these polygons?
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0answers
77 views

Smoothing MODIS LAI? [closed]

I am trying to smooth 8 days LAI data from MODIS and managed to work around it with several algorithms such as loess, Savitzky–Golay, smooth.spline etc. This is pretty much going well if the level of ...
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1answer
54 views

Exporting render of polygon after applying smooth geometry command using QGIS?

I have recently discovered the smooth($geometry,x) command in QGIS which is very convenient for me. However, when exporting polygons, the "smoothness" obviously goes away as the vertices are untouched ...
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1answer
177 views

Blurring raster data across tile boundaries?

I have a raster dataset that is made up of 280 tiles, 51Gb total. I need to smooth/blur the data, retaining the same resolution. I would like to blur across tile boundaries, where possible, so that ...
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1answer
1k views

GEE - Using Savitzky-Golay filter over an Image Collection [closed]

I'm trying to generate a smoothed MODIS(MOD11A2) time series by using the Savitzky-Golay filter. There is this github repo https://github.com/Fernerkundung/EarthEngine_scripts/blob/master/...
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1answer
34 views

How to apply smoothing filter only to way bigger than specified number of nodes, length, area?

I am try to smooth data obtained by vectorization of a raster image by applying a series of filters in GRASS GIS. Once of steps involves using the Douglas-Peucker filter. However, I need to apply it ...
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1answer
2k views

Smoothen Line vector QGIS

I am working on a publication and would like to make my schematic visually pleasing. The amount of detail is too high and the image would be better If I could simplify and smooth my line and polygon ...
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1answer
1k views

Data smoothing of Sentinel-2 NDVI time series chart in Google Earth Engine?

I am exploring Sentinel-2 time-series NDVI with Google Earth Engine. In another post I learned how to plot a NDVI time series chart. I know that there are many smoothing methods for reducing NDVI ...
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3answers
547 views

Smoothing raster with binary cell values

Main question towards the end. Details follow now: I have a slope raster Region: Bern, Switzerland CRS: EPSG:2056 - CH1903+ / LV95 - Projected Extent: 2587757,...
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1answer
39 views

Mapnik upsampled raster isn't smooth

I'm using Mapnik to show a map with hillshading. It works well when displaying it up to my tiff's native resolution and a little bit above, for instance at zoom 13 (dataset is SRTM30): But then if I ...
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0answers
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World DEM speckled outcome solution

I have a world digital elevation model which has been classified into 5 showing the different heights. My issue is that viewing and printing this image as it is results in a speckled look due to the ...
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1answer
102 views

Generalizing slope raster in Mapinfo?

I am working on calculating a slope raster in Mapinfo using a 15cm DEM derived from a LiDAR point cloud and the output data will have 3 predefined breaks displayed so I need to blur those relatively ...
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0answers
68 views

Importing .geotiffs and wavelet denoise plug-in - GIMP

I am trying to run the wavelet denoise plug-in tool on GIMP to smooth a .geotiff. Unfortunately when I import the .tiff, the spatial refernece is lost and the image appears black. My goal was to ...
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0answers
44 views

Obtaining a smoothed DTM?

I am use AcGIS 10.1 and have a DTM with an 8 m grid resolution. Which tool could I apply to smooth the surface?
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0answers
26 views

Smooth Data Values Across Geographies with Zero Population

Looking to fill in gaps through generalizing a population count across U.S. counties. I.e., if a county has 0 population, but is surrounded by 5 non-zero counties, then change the 0-population county ...
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1answer
55 views

Remove small interstices on the edges of a polygone

How can I remove the white interstices on the edges (and interior) of a polygone or polyline, as represented in the first figure below? I want to get smooth and continuous edges, capturing the global ...
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0answers
281 views

Optimized smoothing of stream lines generated from Arc Hydro? [closed]

Has anyone found an effective ArcGIS 10.3.1 workflow for smoothing streamlines generated from ArcHydro...or hydrology in general? (Fill -> Flow Dir. -> Flow Acc. -> Stream Def. -> Stream Seg.-> ...
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0answers
197 views

Smoothing borders of polygons taking a layer of points into account

I'm trying to smooth borders that separate clusters of points. GRASS instrument v.generalize.smooth works pretty well, except that in some cases the points end up on the wrong side of the smoothed ...
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0answers
85 views

Avoiding tiling/mosaicing in resulting image when Pan-sharpening Gram-Schmidt?

I mastered to georeference some declassified Hexagon satellite imagery from the 60s and would like to use it to pan sharpen a current Sentinel satellite image (already done as RGB). It is very ...
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154 views

Why do I get invalid elements (polygons), when smoothing a vector layer (smooth geometry)?

The problem occurs, when using the commands "Smooth geometry" or "v.generalize.smooth" in QGIS. The shapefile, which I want to smooth, shows a flood water level and looks like this: The water level ...
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1answer
6k views

QGIS Raster map, smoothing pixels

I am trying to generate a map in Qgis which makes it possible to see the temperature of a region during a heatwave. This was a great succes. However, I want to add shades as well, since shades lower ...
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278 views

GRASS r.denoise error

I have installed r.denoise, put mdenoise into QGIS2.18/bin and installed "pip install pyproj". However when I try to run r.denoise on STRM DEM, a get this error: ERROR: Unable to open file <...
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1answer
1k views

Continuous smoothing of raster using R?

I have a dataset on some villages like this on a grid: I want to fill the space of the whole grid so that each grid cell has a value that reflects the pressure from the surrounding villages (i.e., ...
5
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1answer
663 views

Snap existing line vertexes to nearest line in MapInfo

I have driven along some roads and registered some information about the state of the edge of the road. The GPS coordinates are not very precise, and I would like to smooth or snap the tracked lines ...
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0answers
131 views

Smoothing out polygons without gaps? [duplicate]

I'm converting a raster data to vector data. The problem is similar to this: How to smooth large vector polygons from Raster But what I need to know is how can I handle out the gaps that are formed ...
2
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0answers
901 views

Leaflet: Smooth lines between points without control points? [closed]

Goal I want to connect points using a polycurve or curved lines in Leaflet in a scalable way. If possible, without defining control points. Approach I'm using the Leaflet.curve plugin which offers ...
3
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1answer
335 views

Methods behind qgis:simplifygeometries and qgis:smoothgeometry?

I would like to know on which method (e.g. Douglas-Peucker line simplification) the modules qgis:simplifygeometries and qgis:smoothgeometry are built on. I cannot find further information on these ...
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0answers
63 views

Rule of Thumb for setting smoothing parameter

I'm trying to model some binary data (disease infections) using indicator kriging in the Geostatistical Wizard in Arc 10.3. For presentation purposes I'm using the smoothing option. Is there a rule of ...
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1answer
302 views

Raster data like heatmap from polygons w.r.t their own values

I have polygons as below, and each polygon is assigned to some value. What I'd like to do are ... Smoothen boundaries (Values should change more smoothly around boundaries) Fill N/A part properly ...
2
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1answer
1k views

SAGA Gaussian filter lower value than 1?

I'm smoothing a 2 meter DEM using the Gaussian filter in SAGA through QGIS/Processing and the smallest amount for the smoothing of the Standard Deviation value of 1 which for me is too much, it all ...
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0answers
186 views

Smoothing relatively flat DEM for terrain and hydrologic analysis

I'm trying to do some terrain and hydrologic analysis from a 1/3 arcsecond DEM that I downloaded from the USGS National Map website. The issue I'm having is that the area in question is central ...
2
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1answer
83 views

Gap filling for linear features using ArcGIS Desktop?

I have a Landsat time series from which I derived NBR using bands 4 and 7, and delta NBR (to show changes). I then set a threshold based on the mean and standard deviation delta NBR values to ...
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1answer
1k views

Looking for a tool to smooth edges of raster areas in QGIS

I am looking for a tool which helps me to smooth primarily edges/outgrowths of raster areas/zones in QGIS/GRASS/SAGA. I particular, regarding the image below, I would like to reduce the single lines (...
3
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0answers
321 views

gdal_grid invdistnn with smoothing?

I am trying to generate a raster with many pixels (10240x10240) using the gdal_grid tool but I have problems choosing the right interpolation algorithm. I have a dataset with varying point density (...
2
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1answer
1k views

Smooth linestring shapefile

Is there an algorithm to perform a smoothing of a linestring and maintain the original points?