Geographic Information Systems

Questions tagged [vectorization]

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

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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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19 views

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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1answer
30 views

Remove 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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40 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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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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1answer
29 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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22 views

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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1answer
36 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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15 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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1answer
59 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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31 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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1answer
66 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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21 views

Is there a plugin for batch conversion of raster data to vector on QGIS?

I know there is Polygonize but it's just not practical for me because it fails for batch process and there a lot of files that I want to convert in one go. I'm dealing with temperature data stored in ...
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51 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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2answers
237 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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181 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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24 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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37 views

Raster to Lines fails (R)

I have the following set of images where a set of 8-neighbor contiguous pixels are outlined in each image, representing a line. The images are distinct, but the lines generally run from left to right. ...
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38 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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108 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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1answer
53 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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1answer
85 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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1answer
172 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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2answers
39 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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1answer
81 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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2answers
165 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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2answers
55 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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1answer
422 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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136 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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75 views

Telling gdal_polygonize.py how to interpret colors / what does the `DN` field mean

I have lots of raster files I am converting to polys with gdal_polygonize.py. All these images have a consistent palette which I'd like to map to an attribute in the resulting polygons. On most ...
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30 views

Generate multiple polygons based on JPEG image?

I have a number of image files depicting polygons (the original shapefiles are lost). Is there a way to automatically create new polygons in GIS, based on the form of the shapes visible in the image? ...
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1answer
65 views

Load GeoTIFF band value into PostGIS

I am trying to upload a geoTIFF file into my PostGIS database. Using raster2psql, it works. raster2pgsql -I -C -M *.tif -F -t auto mytablename > mytable.sql psql -d mydatabase -f mytable.sql ...
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26 views

Refine Raster Layer / remove Color bleeding

I have a Raster layer of Population density in a low resolution. These raster layer has color bleeding between the different population areas. Is there a way, to remove them in QGIS like color ...
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1answer
57 views

Finding external boundary of bunch of vectors (using R libraries)

I have vectorized raster as in the image. This is actually 1419 polygons in SpatialPolygons class object. I'm looking for a method which would allow me to extract the one most external polygon (...
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175 views

Converting historic map data (raster) into polygon format? [closed]

How do I convert historical buildings from map data (raster) into a polygon format? The historic maps that I am referencing are the Sanborn Fire Insurance Maps. Here is the link to an example in case ...
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337 views

Digitizing contour lines from a picture in QGIS

I have a map with isobaths (water depth), like in this picture, and I would like to digitize them. Is there any tool or procedure in QGIS that can recognize the lines in the picture and create a ...
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79 views

Polygon to Raster conversion: Raster shifted ~10m horizontally. How to fix?

I converted a number of polygons into a raster. The cell size is correct but the raster has shifted ~10m horizontally. Is there an issue with my method or is there a tool I can use to fix this?
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1answer
212 views

Extracting GeoTIFF colours and adding to equal geometry shapefile

I have the following map in .png-format that I would like to replicate, but I cannot obtain the original data. The map shows the current water supply vulnerability for local municipalities in South ...
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1answer
56 views

Loading georeferenced map TIFF image into shapefile using ArcMap?

I need to add this Lake County townships map into a shapefile that contains other counties' townships. The shapefile's fields are: Township, Shape, Shape_Length, Shape_Area and County. How can I do ...
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1answer
1k views

Converting large raster to vector?

I have a shapefile which contains 10.000 polygons and I want to know how many of them falls on a specific land use. Unfortunately, the land use map that I have to use is a raster map and not a vector ...
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1answer
832 views

Converting raster to vector in QGIS?

I have reclassed my data so show areas were wind speed is greater than 5m/s and were it is not. I have converted this raster file to a vector file however it showing as one single colour and not ...
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1answer
561 views

Converting each Rastercell to its own Point-Vector, Google Earth Engine

Related Post My goal is to perfectly obtain one vector point per raster cell, located at the Center of the RasterCell Running .reduceToVectors() with the scale argument retrieves vector points, but ...
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1answer
605 views

Converting Raster to Vector, Google Earth Engine,

By running the code, one obtains: FeatureCollection (Error) Image.reduceToVectors: First band ('x') of image must be integral. I don´t understand this error. My goal is to convert the pixel values ...
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1answer
67 views

How do I turn a fog belt zone raster map into a geographic map of expected fog?

I'd like to make a map that shows the amount of fog by San Francisco neighborhood. I'm using QGIS. I have some of the pieces: a geoJSON file for each of the neighborhoods. a raster map with a ...
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2answers
1k views

Converting raster to vector from multiple raster values?

I have a raster GeoTIFF with values from 0 to 255 representing intensities. I want to Vectorize this information, but in ranges of 25. As an example, I want to create a layer in which polygon islands ...
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204 views

How to delete little geometries without hole in python script

I'm writing a python standalone script from a old PyQGIS script. Input data is a raster of which I would like to delete little areas. In the PyQGIS script, I vectorized it and used GRASS v.clean to ...
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1answer
558 views

Vectorizing large-scale binary layer in Google Earth Engine?

I would like to vectorize binary raster layers in Google Earth Engine in order to be able to use the geometry of the resulting FeatureCollection in other tasks (e.g. clipping data or similar things). ...
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1answer
498 views

How can I collect training samples using ee.Image.sampleRegions() and an existing raster layer in Google Earth Engine?

I would like to sample training data from some raster data source (e.g. Sentinel-2) based on labels extracted from an already available dataset (e.g. some binary layer or classification map) in Google ...
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126 views

Doing automatic vectorization in ArcMap?

I'm using ArcMap 10.6; ArcScan. I am trying to run an automatic vectorization on my .tif file. I've cleaned up my raster, and am doing Start Editing - Vectorization - Show Preview (looks good) - ...
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1answer
82 views

How to merge pixel values to the nearest maximum value based on area in a classified raster?

We have a raster image with 9 discrete values. Generated the image using SAGA's Terrain Analysis -> Morphometry -> TPI classification technique. Now, like to merge pixels which occupy certain area (...

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