Questions tagged [vectorization]

The conversion of raster data (an array of cell values) to vector data (a series of points, lines, and polygons).

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QGIS: Converting Rasters (Bathyemtric ASCII & TIFF) to polygon

Currently using QGIS 3.16. I essentially want to create a shape file polygon for the extents of bathymetric grids I am currently working with. The grids are high resolution (2m,5m,10m) and come in a ...
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Polygonize/Vectorize large raster

A raster(.tif) of 6.70GB needs to be converted into polygons. The raster is binary (0 & 1), currently I am using Polygonize (raster to vector) and its taking a considerable amount of time and the ...
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186 views

Simplification by constrained anti-aliasing in PostGIS

I vectorized a raster data set, therefore, I'm facing a "steps" effect, or aliasing, due to the fact that the vectorization strictly follows the raster cells. So, the geometry is quite large ...
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Extracting raster outline to a vector geometry

I have a raster data set with an irregular outline (every value outside is NaN) in Python (loaded from rasterio v.1.3a3 ): I'd like to extract its outline to a vector shape (red in the figure below) ...
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Vectorize and export table in GEE

I have a classified image obtained from RF algorithm in GEE. I want to extract and export each class separately to drive. First as an image by this script (for example for class water of ...
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Issues with vectorisation of thinned flow accumulation through r.to.vect on QGIS

I'm trying to produce a shapefile river network from a flow accumulation raster using the r.to.vect function and I've overcome some difficulties regarding bit depth and thinned raster. n.b. I don't ...
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How to transfer simple GeoTiff data into a database

I'm trying to turn a relatively simple GeoTIFF file into a dataset readable by an API. End goal: Build a GET method for an API like /search_by_coordinates?lat=-73.1221&lng=44.4924 and get ...
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6 votes
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Creating a seamless vector dataset from raster with gdal, R or Python

I'm trying to create a seamless vector dataset from an integer raster. "Seamless" as in: not gaps between features and no overlapping features. The tools gdal_polygonize, pkpolygonize, terra:...
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Converting Raster into Vector in QGIS

I am in process of converting one raster file ( JBA Flood score) into Vector file But due to raster size ( Possibly) process seems endless i.e. even after 9 hours process still continue. Is there any ...
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How to polygonize NDVI raster using GDAL?

I have raster with NDVI values. I would like to polygonize the raster to get vector where each polygon is a pixel. I have tried gdal.Polygonize as described in the documentation and that runs without ...
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2 votes
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Contour Polygon Alternatives on QGIS

I am trying various ways to make polygons from raster data using 1 m DEMs. I am using QGIS 3.16 Hannover I have tried vectorizing my data, which does work OK, but I would like smoother boundary lines ...
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Symbol recognition on a scanned image (map)

I have a specific task and I'm looking for possible approaches. What I'm trying to do is this: I have a high resolution (600dpi) scanned, and georeferenced image of a map, and I need to be able to ...
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3 votes
1 answer
290 views

Seeking GIS tool to automatically extract polygon geometries from images

Let's say I have multiple png images like the following one: I'd like to find a way where I can automatically draw polygon geometries on this image. Something like the following: My expectation is ...
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1 vote
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Draw polygon (vectorize) raster based on same colored pixels -- getting bad polygons

So, I have a TIF georeferenced map and a rather messy shape that I need to digitize. It is green but has a lot of holes in it that are light green color. So, I want to capture all green pixels and ...
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2 votes
1 answer
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Scaling a soil profile Raster to georeference and vectorize Raster data

I have pictures of root patterns, where each root is marked by a point. We worked on soil profile walls, so there is no coordinate system to use as a basemap. I loaded it to QGIS and classified it ...
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Conceptual question on comparing rasterized data with vectorized (polygons) data

I've got this doubt on how to best proceed with the following situation: I would like to compare two datasets, one (model_data) is a raster (NetCDF format), with lat, lon and time as coordinates, ...
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Automatic extraction of ditches and breaklines from point clouds/ DEM

I am trying to automatically find Ditches and break lines from a point cloud of a rural but flat area. So far I tried to covert LAS to DEM and generate 'streams' using Flow direction, Flow ...
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QGIS Polygonize algorithm, converting raster to vector files different from Mac and Windows

We are trying to convert a single-band raster files with values 0s & 1s to Vector. When using the QGIS's internal algorithm 'Polygonize', the result is slightly off from a Mac then the ones from ...
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1 vote
1 answer
127 views

Wrong features when exporting vectorized raster data to a file using GeoPandas after applying a filter and a dissolve operation

I have a raster file with black areas having a value of 0 and white areas having a value of 1, resulting from a visibility analysis: I vectorized this raster after loading it with rasterio: import ...
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Transforming a raster .png image to vector file

I have been working with FEMA flood maps to georeferenced and then digitize the maps by hand drawing polygons of the flood zone features. I have tried some workarounds to make the digitization process ...
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How is it that ArcMap and QGIS produce feature classes with different numbers of points and different coordinates from the same TIFF?

I have a 300m by 300m B&W TIFF map of Brazil, and I need to convert all the pixel values into a point feature class. When I do it in ArcMap using Raster to Point, I get a feature class with 92,054,...
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Google Earth Engine Reducing Landsat Global Inland Waters Raster to Vector

I'm trying to create a vector outline of the water areas of the Landsat Global Inland Water raster in Earth Engine. I get the error "Line 3: water.addBands is not a function" from the ...
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2 votes
2 answers
366 views

Vectorizing raster with values between 0 and 1 in QGIS

I am working on QGIS. I have a raster of EVI, in which values are comprised between 0 and 1. I need to vectorize this raster in order to make an intersection with another vector. My issue is that when ...
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Distance between two vector lines in each east-west raster row (in QGIS)

I have 2m-resolution raster LiDAR data of a marsh edge from two moments in time and I am trying to calculate how much the marsh has "retreated" between the datasets. I used the LiDAR data to ...
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r.thin (GRASS) not giving correct result

I have raster image of road feature. I want to extract line feature from it. So I run r.thin tool on it of parameter - { 'GRASS_RASTER_FORMAT_META' : '', 'GRASS_RASTER_FORMAT_OPT' : '', '...
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5 votes
2 answers
101 views

Removing additional lines from vectorized stream network

I have a large raster stream network (excerpt below) in QGIS that has been thinned using r.thin (light blue squares) and then vectorised using r.to.vect (pink lines). However, because some of the ...
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174 views

How can I vectorize contour lines from a DTM in QGIS?

I'm using QGIS 3.16. I am trying to do the following: Starting with a DTM model (geoTIFF format) I am computing the contour lines (100m) with QGIS. So far, so good. In order to import the results into ...
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1 vote
0 answers
65 views

QGIS does not polygonize [closed]

I have a .tif which I want to have polygonized. I take the Raster/Conversion/Raster to Polygon. QGIS 3.12 starts the process but never ends (once I waited half an hour). I maybe don't see a mistake. ...
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1 vote
1 answer
496 views

Creating a polygon from all raster values >0 in QGIS?

I have a raster layer with two values, 0 and 1. I want to create a polygon shape from all the 1 values. I expected the "raster to vector" tool to achieve this, but this created another grid ...
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Raster Values into Gridded Polygons with Same Cell Size using ArcMap

I have data in the form of a raster with 1 km x 1 km cells. I need to transfer it into a vector polygon grid layer (USNG) which also has 1 km x km cells, but has divergence around UTM zones and does ...
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1 vote
1 answer
283 views

Using TIFF file in Intersect tool of ArcMap

I am attempting to do some geoprocessing with a CSV file and a TIFF file (trying to use the Intersect tool), but am experiencing some trouble with it. I can't seem to be able to input the TIFF file as ...
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30 views

FireCCI51 on Google Earth Engine: burnt area as shapefiles

How can I export my results as shapefiles (polygons) from the burnt area results (raster)? I intend to export these shapefiles to ArcGIS for further anlysis on a specific national scale. Link to ...
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1 vote
1 answer
319 views

Vectorize a raster TIFF based on its different class colors

I am using QGIS 3.16 and I have an int ratser tiff file, which shows classified land covers obtained from Sentinel-2. I need to create polygons over each class to classify and visualize each group in ...
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73 views

Creating shapefile of a raster image in QGIS 3.6

I use QGIS 3.6 on Windows and I have been trying to convert raster images into shapefiles. I managed to do that for Digital Terrain Models only, using the conversion --> vectorize tool in the qgis ...
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1 vote
1 answer
367 views

Converting Raster to Polygon in ArcMap

I've prepared my Shapefile in ArcMap 10.7.1 by Raster to Polygon. When I am opening this shapefile in ArcMap its showing a rectangular polygon around the shapefile like this: When I select this ...
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7 votes
1 answer
163 views

Optimizing identification of tree stand boundaries

I am working on a workflow to identify tree stand boundaries. My desired result is the blue lines - I know it will never be like that, but I need it to be as good as possible. My best result is the ...
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2 votes
2 answers
2k views

Extract cells above certain values of raster file

I have a very large raster layer and with the values for noise emission. I'd like to extract all cells which are above a certain threshold value (e.g. 50 db) and convert them to an ESRI Shapefile so ...
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5 votes
2 answers
286 views

Identifying tree stand boundaries

I have a forest area, where I need to identify all the dividing lines between tree stands. I have a different amount of rastar files (RGB, NIR, DTM, DSM), and need an output with the boundaries as a ...
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1 vote
0 answers
39 views

Vectorizing a raster zone map without the lines turning into squares QGIS

Raster zone lines turn into squares after vectorizing my raster because of pixels between color zones QGIS
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2 votes
0 answers
55 views

Is my raster too large to realistically vectorize in ArcGIS Pro?

I'm new to ArcGIS Pro so go easy on me. I have a raster file(.img) of the continental US broken up into 30x30m grid resulting in about 10 billion individual pixels. I need to index each of these ...
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1 vote
0 answers
384 views

ArcScan equivalent in QGIS

Is there any thing in QGIS which can perform operations like ArcScan? I put WMS polygon layer as a base map. I save it as PNG and when I add it as a raster layer, I can vectorize it with ArcScan. I ...
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1 vote
1 answer
97 views

Automatic Vectorisation in ArcGIS

Is there any method or tool/model for ArcGIS to draw automatic line based upon raster data values. E.g i have a DEM and i want to automatically generate a line feature passing through all those pixels ...
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0 votes
1 answer
146 views

Error in overlay - formula not vectorized

I've run into another error while trying to get my predictive model to work. My base model is basically done (extracting locational parameters from archaeological sites in an area, and calculating a ...
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2 votes
1 answer
432 views

Split single band layer in QGIS

I have a single band raster layer, namely the USGS Global Mountain Explorer Home K3 dataset. It is a 8 bit unsigned integer GeoTIFF of 200 Mb, with 4 grey values each corresponding to a mountain ...
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0 votes
2 answers
51 views

Two-value raster to generalized polygons (join pixels close together into one polygon) with short computation time in QGIS or ArcMap [closed]

I want to create application map for agriculture based on NDVI map. I have theoretical way how to do it. My raster has two values (1 - red, 0 - green), the raster is quite big (100 hectares with 6 ...
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2 votes
1 answer
252 views

Runtime problem gdal:polygonize processing algorithm

I have a c. 60 MB file containing the GTOPO30 30-arc second (c. 1 km) digital elevation model of Africa. The dataset is described here: https://databasin.org/datasets/2965da954b114ff3b47621e99e3b29ba. ...
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1 vote
2 answers
458 views

Converting raster to polygon through ModelBuilder?

I have a set of raster which I want to convert to the polygon. Below is the model I prepared, but its showing below error. I checked the error code, which explains Alter the name to remove any ...
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  • 385
1 vote
3 answers
99 views

Custom vector data drawing

I'm trying to create a map for a fictional map. I'm using Leaflet to display the map, with tiles, different levels of zoom and so on. Now I need to generate, to "draw", some vector data. Specifically,...
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9 votes
1 answer
740 views

Creating vector (with lines/polygons) from raster based on paper map in QGIS

For a task I have several maps created with GIS that look like the following: I am mainly interested in the colored zones that aren't roads (red) or rivers (blue) and would like to turn these into ...
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2 votes
0 answers
233 views

QGIS is flipping my rasters when I vectorize them

I am using QGIS to vectorize some raster layers. I was able to do this fine a week ago, but now every time I use the vectorize tool, the resulting vectors are flipped upside down. Any suggestions?
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