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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Fastest way to clip millions of small polygons and storing results as JSON [closed]
I have a dataset with couple million farm polygons (around 2.5 million and only expected to grow in the future), and I need to calculate the NDVI for these farm polygons, with some basic stats (...
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Convert a PNG file to a line layer in QGIS
I have a map in PNG-format that looks like this:
I have imported it into QGIS as a raster. I want to create a line layer as a network based on the blue and pink lines. Is there a way to create a line ...
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Converting vectorization (raster to vector) with small steps in values in QGIS
I have a raster file that contains water depths in m. The water depths are the only attribute and should be transferred to the vector layer.
The raster files have a cell accuracy of 1m x 1m. I would ...
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Extract a vector from a raster with a single boundary in QGIS
I have a "problem", I need transform a raster in a vector and it works but some pixels like the one in the print it is separated from the boundary, and for my use (a specific use of ...
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ReducetoVectors in Google Earth Engine not working with the Mollweide transformation. Need to calculate zonal statistics for global scale analysis
My study is a global-scale analysis of the factors driving forest gain, with grid cells as the unit of analysis. I need to calculate the amount of forest gain per ~65km2 hexagonal grid cell at the ...
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Generate points from raster image in QGIS
I'm hoping to generate a new vector file from select points from a raster image in QGIS. I don't know if it is possible.
For instance, I would like to generate a vector point file that puts a point ...
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Convert topographic map to vector and text
I have a topographic map in TIFF format and I vectorized it in QGIS (3.22.0). For my project I needed the settlements, which I was able to extract. More importantly are the names of the settlement. ...
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GEE Export individual FeatureCollections as shapefiles from an image Collection
I have run an NDWI index for an Image collection and thres holded the results, which I want to import as individual FeatureCollections (shapefiles).
My code is of course longer, but teh most importan ...
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Differentiate vertical and horizontal shapes
I have the following shape file:
Each polygonal area (the lines are areas) is one feature in a single Shapefile.
Can anyone think of a simple method that can be implemented with qgis to separate the ...
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How to convert raster to vector by generating center lines?
I need to vectorize the raster by keeping one center line trough the boundary pixels. My solution would need to be very similar to this question: Converting raster to vector by generating center lines?...
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Abrupt error when trying to run model with viewshed as batch process
I am trying to run the following model as a batch process. In summary, I take a DEM raster layer and a number of individual points as separate .gpkg files in a directory (these points have been ...
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Smoothing a vector layer in Google Earth Engine
I extract riverbanks out of Landsat images at Google Earth Engine. After the vectorization of my raster image I receive a shapefile of the riverbank with many unwanted vertices. How can I smooth the ...
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Why r.to.vect process takes too much time with topology analysis?
My task is to vectorize a standard landuse map (PROBA-V discrete classification) for extent 118.747182 54.231218 124.946218 60.060467 degrees. Raster is too detailed for me, so I generalize it.
I use:...
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Chain the output of gdal_polygonize to ogr2ogr
I am doing a two step process:
Polygonize a PNG raster via gdal_polygonize.py
Add a custom field named id
Upload the resulting vector to PostGIS via ogr2ogr
I am currently doing it in two steps, ...
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Vectorizing all pixels as separate polygons using rasterio
I use rasterio.features.shapes and use the geometry of pixels in raster data to create polygons for each pixel. Pixels with the same value merge these pixels if they are adjacent.
What I want is for ...
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QGIS .tiff to shapefiles by extracting colours
So I have the following raster file:
I would like to edit it so that I export all green, blue or purple areas as a single, new .tiff. Afterwards I would make a vectorization to be able to process the ...
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What are strategies to simplify a vectorized raster layer?
For a GIS web viewer I am building, I plan to use large sets of vector data on coral reefs (source: Allen Coral Atlas). When viewing the downloaded data, it seems that the original source was raster ...
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Create clipping masks using contour lines in QGIS
I'm new to QGIS and GIS in general. I'm trying to find a way to create height layers automatically and then use them to clip other layers.
In detail: Below is my area of interest. I have a raster ...
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Visualization and vectorizing for AI in Google Earth Engine
I'm glad to find this space, I come from a background in economics and do not know the first thing about GIS (hope to learn as I go with this project).
I found an interesting dataset (https://...
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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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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, such as a Shapely ...
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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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 ...
