All Questions
1,003 questions
1
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0
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47
views
Classifying spatial data using QGIS [closed]
I have two files: geologie.dbf and Legenda_Geologie.xls. I need to classify some regions within the area that I am studying but I am not exactly sure how to do that.
Do I need to manually type the ...
- 11
1
vote
1
answer
44
views
QGIS expression to symbolise road condition between values
I am using QGIS 3.22.16. I try to symbolize a road condition. The result wanted is:
Equal 2 if Minor > 0.3
Moderate > 0.2
severe > 0.1
Equal 1 if
0.2 < Minor <0.3
0.1 < Moderate <...
- 360
0
votes
0
answers
27
views
How to solve the problem 'User memory limit exceeded' in supervised classification?
I'm trying to do supervised classification on google earth engine. I haven't done a lot of supervised classifications on gee but system keep saying:
User memory limit exceeded.
How can I solve this ...
1
vote
0
answers
36
views
Opening .img file created in Erdas Imagine 2023 in Erdas Imagine 2022
I am having an issue working with a file created in Erdas Imagine 2023 in Erdas Imagine 2022. I ran a tool with the output .img. However, the .img format seems to be different in Erdas 2023 vs Erdas ...
- 11
0
votes
0
answers
26
views
Using both Categorized and Graduated renderers simultaneously in QGIS
I am working on a map in QGIS 3.28 and would like to display two different types of information simultaneously using both the Categorized and Graduated renderers. Specifically, I want to categorize my ...
- 101
0
votes
0
answers
25
views
How to classify points in a QGIS shapefile by size based on a numeric attribute (tree canopy diameter)?
I'm using QGIS 3.28. I have a shapefile containing point data, where each point represents a tree, and I want to classify these points by size on a map. Specifically, I have a numeric attribute for ...
- 101
2
votes
1
answer
79
views
Defining not-custom graduated style to polygon layer in PyQGIS
I'm writing some scripts on the PyQGIS 3 console to build a plug-in and I would like to create a color-graduated style for my vector layer. I read Applying graduated renderer to polygon using PyQGIS, ...
0
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0
answers
38
views
Classification based on two attributes in QGIS
I am using QGIS occasionally to illustrate landscape analyses, assessments and resources. Nothing too fancy at this stage.
I have been wondering how I can classify my map based on two attributes.
In ...
- 1
0
votes
0
answers
31
views
Wrong pallete in Gradient Tree Boost classification
I'm using GTB to classify LULC, and when I'm trying to visualize the image it looks like this:
//Gradient Tree Boost Classification
var classifier = ee.Classifier.smileGradientTreeBoost(500).train({
...
0
votes
1
answer
31
views
Supervised classification ALOS-PALSAR Google Earth Engine
I need to create a supervised classification for flood detection with ALOS PALSAR in Google Earth Engine. How can I do this?
0
votes
0
answers
41
views
Use a mosaic image of aerial imagery with the classification wizard in ArcGIS Pro
I've been trying to run the classification wizard tools in ArcGIS Pro with a mosaic of 4 aerial multiband images. I have all the licenses to do so and the mosaic image is multiband.
I'm able to run a ...
0
votes
0
answers
32
views
How to set the block size parameter for prepare a high point-density PointCloud dataset for training a model with ArcGIS Pro
I have a mobile point cloud dataset with following information:
point density: all returns 126.91 last only 117.75 (per square units)
Point spacing: all returns 0.09 last only 0.8 (in units)
For ...
- 179
0
votes
0
answers
22
views
What is the optimal number of samples in a random forest classification?
I am conducting a supervised classification as part of a LULC analysis. I have 8 classes with sample sizes maxing at 500. However, I am still seeing some misclassification and want to add more classes,...
- 1
0
votes
0
answers
101
views
Training Samples Manager in ArcGIS Pro takes each polygon as a class
I am trying to create segmentation on satellite image I have. I have something like 1000 polygons to use for training and I'm using the Classification Wizard. I have uploaded the sample polygons, but ...
- 2,215
0
votes
0
answers
26
views
Merging non-overlapping classified rasters with varying nb of classes
In ArcGIS Pro 3.2, I have several tiles of 1km² as composite rasters (4 bands+NDVI+NDVIre+DSM). I classify each tile independantly with SVM and segmentation, using a training scheme with 8 classes. ...
- 19
-1
votes
1
answer
202
views
Link drive folder to gee: Display tiff images from drive to gee
I have classified images using many different programs on gee and exported a series of classified images to a folder on my drive. I don't know how I can link that folder to gee so I can display the ...
- 1
1
vote
1
answer
38
views
Apply symbol from one category to other categories and retain color already set
Is there a way to apply or change a symbol of one category to other categories without changing the already set color in the QGIS symbology window?
After setting up a symbol, I can change the color by ...
- 180
0
votes
1
answer
129
views
Using large datasets for training in Google Earth Engine
I created a training dataset using polygons outside of GEE and I want to use them now in GEE for a supervised classification in Sentinel-2 images.
However when I try to create training points from it ...
- 63
4
votes
1
answer
106
views
Sorting Classification by another field
I am currently using the QGIS software. I use rule-based classification to extract the monetary values from a field and display them as symbols. For map legend purposes I need to concatenate the ...
- 41
1
vote
0
answers
38
views
Classify vector layer by area quantiles in QGIS
I have a vector layer with aroud 400 features, each having an assigned value (here displayed as a label).
I want to classify it into 5 groups (10%/20%/40%/20%/10% of the total area) based on the ...
- 11
4
votes
1
answer
259
views
Doing simple manual classification of LAS using QGIS
Are there any basic tools for lidar classification in QGIS?
Id like to do simple function like reclassing single points, classing points inside a fence or above a line. something similar to the basic ...
- 49
0
votes
0
answers
22
views
Affect on classification for two different Sentinel images taken at the same time with slightly different color values
I am running a supervised land-use land-change classification across multiple Sentinel images. These images were taken at the same time of different but overlapping areas. However, despite being taken ...
- 1
0
votes
0
answers
39
views
Classification in ENVI
I classified multiple images using ENVI modeler and I would like class statistics for each image. Is there a task available in ENVI modeler that can do this? I know I can right click each image and ...
- 1
0
votes
1
answer
43
views
Difficulty displaying custom LAS attribute in ArcGIS Pro symbology
I have computed a vegetation index for my point clouds and have added it as a new attribute to my LAS file, and saved the updated las file using the following code-
lz <- readLAS('x.laz')
rgb <- ...
0
votes
1
answer
164
views
Plotting Sentinel-2 Level-2A Scene Classification in GEE
I am interested to visualize the result of Scene Classification (SC) that is automatically performed during the production of level-2A products. I am using GEE.
I have read this page and this page and ...
0
votes
0
answers
46
views
What data does clustering use from multiple raster files?
I currently have a series of rasters of the same area across different times. The data is categorical: the product of a supervised classification used on LANDSAT data run on ERDAS Imagine. Each ...
- 23
1
vote
1
answer
97
views
Change select color in a raster in QGIS using Serval or Value tool
Is it possible to edit the table view of a raster that you see in the Value tool?
Alternatively
Using Serval, once we have a selection polygon can we choose a specific range of raster values within ...
- 8,298
2
votes
1
answer
109
views
Does QGIS have a functionality similar to Flicker in Erdas Imagine?
I am trying to replace an Erdas Imagine workflow with QGIS and I have got most of it working but can't find a solution for fliker. We have it set to turn an image on and off every few seconds to ...
- 8,298
0
votes
0
answers
34
views
Erdas - Export LUT Instead Of Real Values
I am using Erdas 2022.
I have NDVI index of an imaging, and after creating it, the view shows a LUT which is not the original pixels, which is essentially the automatic stretching of the program.
I ...
- 101
0
votes
0
answers
29
views
Random forest invalid data
I'm trying to classify forest habitats at a 10-meter resolution. I have imported my points from a shapefile that contains habitat categories for each sampled point in the "target" column. I ...
0
votes
0
answers
26
views
Multitemporal supervised classification with spectral signatures in GEE
I need to run a supervised classification on GEE using Landsat image about a determined date with the spectral signatures derived from a image of another year but same month. Is it possible?
0
votes
1
answer
516
views
Symbology Class Editing Options Greyed Out
I am trying to add a symbology class to a layer but the options are greyed out. I believe it has something to do with the warning that says "primary symbology relies on one or more fields that ...
- 23
1
vote
1
answer
77
views
Error - Missing property in a classified image
I am trying to classify a Sentinel 2 image composite with some added index bands using Random Forest supervised classification on a collection of sample points generated from a source Dynamic World V1 ...
0
votes
1
answer
160
views
QGIS and percent values in slope map
I create a slope map from a DEM downloaded with SRTM Downloader in QGIS 3.32.0-Lima. I searched in the internet trying to find the way to interpret the values of the left column in percent. For ...
- 9
0
votes
0
answers
68
views
Interactive supervised classification tool greyed out
I'm using ArcMap to perform a classification. The problem is in the classification wizard, all tools like maximum likelihood classification and other are still available except the interactive ...
- 1
0
votes
0
answers
46
views
Excluding 'No Data' Pixels When Counting number of pixels in an AOI with ERDAS IMAGINE
I'm working with Landsat imagery in ERDAS IMAGINE 2014 and have encountered an issue with 'no data' pixels within my Area of Interest (AOI). The AOI includes unwanted 'no data' pixels that are ...
0
votes
0
answers
56
views
Zonal Statistics in QGIS
I am using raster layer zonal statistics in QGIS. I want to quantify the water yield contribution of each LULC class, but the results of the zonal statistics is greater than the value given by the ...
- 21
2
votes
1
answer
944
views
Semi-Automatic Classification Plugin Problem - No band encountered
I am new to the Semi-Automatic Classification Plugin. I am currently trying to produce Land Surface Temperature maps using satellite images (Landsat8) from Earth Explorer.
I have downloaded the B10, ...
- 21
0
votes
0
answers
72
views
What does the metadata tell you about an image and its sensor?
I'm using a software called ERDAS and my tutor says that the Metadata can be used to detect which sensor your image came from. Is there anything you can tell me that links the metadata to the sensor?
...
0
votes
0
answers
22
views
Merging Subswaths with ERDAS Imagine
Does anyone have experience with merging subswaths of a SLC Sentinel 1 image in ERDAS Imagine? I cannot find the right function for it.
0
votes
0
answers
37
views
Band not recognised - seagrass mapping on GEE
// Load Sentinel 2 raw imagery and filter it to all images in 2023.
var S2data = ee.ImageCollection('COPERNICUS/S2_SR')
.filterDate('2023-05-01', '2023-08-01')
.filterBounds(poi)
.filter(...
- 1
0
votes
1
answer
70
views
Using existing GeoTIFF as training points for random forest classifier (Landsat 7)
I am new to R and GEE. I am trying to establish a link, using time series analysis, between land use change (different classes) and evapotranspiration (if possible also temperature, precipitation and ...
1
vote
1
answer
357
views
Reclassify points in a LAS file using laspy
I am trying to change the classification of all points in my las file above a certain height (z value) from 2 (ground) to 1 (unclassified). I wrote the following code to do this:
las = laspy.read(&...
1
vote
0
answers
57
views
QGIS Classifications on 10km^2 square grid
I am new to QGIS, and I have a problem that I don't know how to solve:
My goal is to have a 10km x 10km square grid of Europe where each cell of the grid is classified by land use. With just a few ...
1
vote
1
answer
423
views
Layers not getting displayed using Map.addLayer in GEE
I am writing a code to classify glacier features using various masks. The problem however is that none of the processed images are getting displayed. They are getting processed and the 'print' ...
1
vote
1
answer
49
views
Select legend items in ArcMap
I have classified class interval with pixel value (i.e. >1 & < 0 ) as Non-Bamboo area after excluding these values in image classification. However, these classes appear in 2 rows in legends ...
- 83
0
votes
1
answer
180
views
How to enable the image classification tool in ArcGIS
I intend to perform a supervised classification on a TIFF image in ArcGIS 10.8. The image is an imagery of an area which I downloaded from my ArcGIS Online account. The goal is to automatically ...
0
votes
1
answer
523
views
Calculate area under each class for a feature in a shapefile
I have a shapefile that you see in attached picture and you can see it has eight classes for a feature shown in picture. How do I calculate area under each class. I would like to export area ...
- 21
0
votes
0
answers
121
views
Google Earth Engine Error for random forest classification
I am working on random forest classification to distinguish corn areas, and defining train and test data but I faced an error.
classification: Layer error: ErrorMargin, argument 'value': Invalid
type....
0
votes
1
answer
66
views
Does Landsat satellite image should have raster value to -1 and 1?
I am calculating the NDVI for Landsat-8 using the formula as shown below:-
But the pixel value rendered is as shown below: -
But the NDVI values need to be between -1 and +1 however, the value ...
- 83