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Questions tagged [pixel]

In digital imaging, a pixel, or pel (picture element), is a single point in a raster image, or the smallest addressable screen element in a display device. In GIS applications, a pixel may also refer to an imagery layer or other raster data.

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QGIS DEM to elevation Points, pixels not centred

I have a DEM which I'm trying to convert into a point layer in QGIS. I used the raster pixels to points tool, which seemed to work, except that the points are not in the centre of the DEM pixels. They ...
user240982's user avatar
1 vote
0 answers
40 views

What are the shades (vertical lines) in the orthomosaics?

I am an expert on my field. I work with remote sensing. Mostly UAVs. I collect datasets and extract features from it. This year, I started collected with the Astro Freefly and the Sony A7RIV sensor (...
Jose Luis Landivar S's user avatar
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1 answer
56 views

How calculating green canopy cover differs from the sensor utilized

I am an expert on my field. I work with remote sensing. Mostly UAVs. I collect datasets and extract features from it. One of the features is 'green canopy cover' (https://acsess.onlinelibrary.wiley....
Jose Luis Landivar S's user avatar
0 votes
0 answers
36 views

Converting latLng to screen point

I have a map in RN app on iOS and I have and overlay outside of the map Inside overlay I need to draw a View with some absolute position that will match some LatLng coords on the map I know screen ...
Sedoyjan's user avatar
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0 answers
30 views

Extracting forest patches using square Kernels around shapefile point data in Google Earth Engine

I have an image representing global forest cover named minArea. Pixels are valued 1 or 0 (tree cover or no tree cover). I also have a shapefile imported through my assets of XY coordinate data. ...
MrBeardo's user avatar
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0 answers
49 views

Pixel by pixel comparison in Google Earth Engine

I have attempted to write a surface water detection program in GEE using the NDWI, with otsu thresholding and canny edge filtering. I would like to evaluate my approach and I was thinking of using the ...
mdansfo's user avatar
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2 votes
1 answer
71 views

How to create a layer with only the isolated pixels using QGIS?

I have a raster (with one band) of a land and there is some islands surrounded by No Data. I would like to create a layer consisting only with these isolated small groups of pixels (group maximum size ...
masterOfGoogleMaps's user avatar
1 vote
0 answers
27 views

Improve image quality of "Decoration"

I imported a key using Decorations -> Image in QGIS 3.32 and the quality is poor, especially if the image is made smaller. I do not mean that the actual image file is small, but that displaying the ...
Nadka's user avatar
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0 answers
29 views

How to save the error: Array: No numbers in 'values', must provide a type

I'm a beginner of coding and GEE. I'm trying to extract the NIR and Red band time series data of each pixel in the survey area with cloud masked. However, when applying the code below I used to do ...
TIANRUN XUE's user avatar
6 votes
2 answers
236 views

Shifting existing points (shapefile) to the highest raster pixel value in 5m buffer

I am trying to move 1700 points (of an existing shapefile) to a new pixel of a raster layer. If the dot is already in the highest pixel of the NDVI raster layer then no need to change. The criteria ...
Tom Runge's user avatar
0 votes
1 answer
38 views

Adding pixel-level classification to ee.ImageCollection

I am working with ee.ImageCollection('LANDSAT/LE09/C02/T1_L2') data pulled from earthengine-api in Python. I have previously defined a function to mask cloud, shadow, water, and snow. based on the ...
richard.turner's user avatar
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0 answers
49 views

No numbers in 'values', must provide a type

I'm facing an error when trying to export all the pixel value of a ImageCollection. The error is : But when I check the corresponding image in my dataset I don't see anything different from the other....
Aurélien Lengrand's user avatar
0 votes
1 answer
42 views

Exporting pixel value of a dataset

I'm trying to export the value of a dataset for each pixel. I made it this way : var chloa_4kmOnly = chloa_4km.select("Chloa_OC3").clip(geometry) print(chloa_4kmOnly) var chloaFeatures = ee....
Aurélien Lengrand's user avatar
0 votes
2 answers
42 views

Wrapping of one huge raster with another raster and saving output such that both the rasters dimensions and crs match

I have two huge rasters, I want my target raster dimensions , height width to match with my source raster and save my target raster into another folder. Since it is huge in size I want to do tile/...
soumik chakraborty's user avatar
3 votes
1 answer
115 views

Counting how many times each pixel is covered in several GeoTIFFs

I have a few GeoTIFFs which might have overlap, I want to find how many times each pixel is covered in several GeoTIFFs. I thought it is best to create a heat map in Python (using GDAL or Rasterio) ...
Ari's user avatar
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0 answers
49 views

What do the numbers on the scale mean when I zoom in and out

I am using a map that overlays carbon emissions over geographies produced by a satellite. When I zoom in and out, the number on the "scale" changes. I want to know what this number actually ...
EmZ's user avatar
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0 answers
56 views

QGIS: Export ShapeFile-Layer with image coordinates

I am completely new to QGIS and I am trying to solve this issue: I have 3 layers: OpenStreetMap, an image and my shapefile layer with polygons. All polygons are within the image. Is it somehow ...
Life4Gaming's user avatar
0 votes
1 answer
93 views

Extract values of surrounding pixels in a raster from QGIS

I can extract values from raster by "raster to points" tool but I need to find values of surrounding eight pixels to the central pixel. And I need to do this for all pixels so I could put in ...
Zaara Kidwai's user avatar
1 vote
0 answers
41 views

Query: Raster alignment in QGIS (pixels without data)

I would like to know if when aligning rasters of different resolutions in QGIS if it is possible that some areas that do not have data can somehow be modified or interpreted to give an explanation ...
Diego_12's user avatar
0 votes
0 answers
97 views

All the pixels in an image exported from Earth Engine have the same value

I'm trying to export an image with 42 bands from Google Earth Engine: Some bands correspond to an index like NDBI for Sentinel 2 images and his equivalent for Sentinel 1 images, other band correspond ...
Roger Godofredo Rivero Morales's user avatar
3 votes
2 answers
142 views

Creating raster based on function of distance to points and assorted attributes in QGIS

In QGIS 3.30 I have a dataset of points associated with several values, call them integers A and B. I want to create a raster with maybe 5km x 5km pixels where the value associated with each pixel ...
Richard Laxton's user avatar
2 votes
2 answers
121 views

Looking for QGIS equivalent of ArcGIS "Group values" tool

I have LULC 8 classes. I want to group them in QGIS into five priority score classes in Symbology, just the same as the function in ArcGIS "Group values". But I can't find the same tool in ...
Bokhir Alikhanov's user avatar
1 vote
1 answer
182 views

Exporting MERRA2 image with Google Earth Engine with same resolution

I am trying to extract MERRA2 columnar dust data from Google Earth Engine for a specific range of dates. I have to download it as daily data so I have converted it from hourly to daily. The image's ...
shravani banerjee's user avatar
0 votes
0 answers
143 views

How to delete Individual Pixels from Raster image in ArcGIS Pro?

I need to remove some pixels that are not in homogeneous land-covered areas. How can I do that? I was told to convert the raster into polygons, but that didn't work, as some pixels were merged ...
Fernando Fuentes Martins's user avatar
1 vote
0 answers
151 views

Cloud pixel filters for Sentinel-2 images

I'm trying to perform a supervised land use classification for a region (Buenos Aires Delta) and a specific time period (between January and March 2017). I'm using Sentinel-2 images processed in GEE ...
Ivan Insua's user avatar
0 votes
1 answer
589 views

Get pixel values using rasterio.sample

I would like to get the pixel values for a single point within a .tif file using rasterio. I have read several previous questions, and implemented the suggestions. Here is the code that I am using: ...
GeoGraphical's user avatar
0 votes
1 answer
30 views

NDSI handling of areas that cross over a pixel

I am using GEE to calculate the NDSI on Landsat8 using a polygon area of 500m. Since Landsat8 has a 30m pixel resolution, I wondered how the partial pixels are handled in the calculations. Are they ...
Fernando Fuentes Martins's user avatar
0 votes
3 answers
179 views

Create raster with angles between single point and all raster pixels in QGIS [duplicate]

I would like to create a raster in which the cell values contain the angle between that cell and a single vector point. It would be as though a line were projected between the cell and the point, and ...
Matt's user avatar
  • 67
0 votes
1 answer
73 views

Merge raster data whilst keeping min value and their layer name [closed]

Using numpy and arcpy I can’t figure out a method to do the following: Merge two rasters which have identical cell alignment keeping the minimum value (e.g compare the pixel values and keep minimum) ...
spk578's user avatar
  • 1,516
0 votes
1 answer
155 views

How can I get the longitude and latitude of a specified pixel (e.g. equal to certain value) with Google Earth Engine?

I want to get the longitude and latitude of a specified pixel (e.g. equal to a certain value) using Google Earth Engine. In other words, I have used "ee.Reducer.min()" to get the minimum ...
ComeTr-2097's user avatar
0 votes
0 answers
94 views

MapServer - Adjust brightness and contrast of a layer

I'm completely new to GIS/MapServer stuff. I'm working on an application that displays geotiff images on a 3d earth/map. I'd like to be able to adjust the brightness and contrast for this imagery via ...
Index545's user avatar
0 votes
2 answers
68 views

Pixels not matching with GDAL projection of Modis LST hdf data [duplicate]

I have used the following the commands to project MODIS LST .hdf data through GDAL in cygwin: gdalwarp -r bilinear -of GTIFF -tps -t_srs '+proj=utm +zone=29 +datum=WGS84' HDF4_EOS:EOS_SWATH:"...
FlipAD's user avatar
  • 1
0 votes
0 answers
73 views

Backward transformation of georeferenced image: from GeoTIFF to TIFF

What's the processing procedure to realize a backward transformation, from a GeoTIFF image to its native array of pixels? Do you have any suggestion?
Claudio's user avatar
  • 26
0 votes
1 answer
420 views

Calculate area NDSI in GEE

I am new to using GEE. I am trying to calculate the area of NDSI values gte 0. For this, I make a function where I already do the conditional. So I have images with values 0 and 1. Then I added a band ...
Mariana Elizabeth Espinosa Bla's user avatar
1 vote
1 answer
265 views

Better workflow for extracting boundary of raster in QGIS

I have got a raster (.tif) which has areas with "no data". I want to extract just the area where i have data. I can do this with gdal:polygonize (1) and native:dissolve (2). But especially ...
fsg's user avatar
  • 682
0 votes
1 answer
61 views

Grouping single-band GeoTIFF with 50 unique values into three categories using QGIS

I have a few (very large) GeoTIFFs from a scientific agency that use a single band to categorize each pixel of satellite imagery into one of about 50 categories ("Native forest," "...
Chris Wilson's user avatar
4 votes
0 answers
110 views

Rectangular cells versus square cells, is there some advantage?

I would say 100% of my work involving rasters is with rasters where the cell shape is square, e.g. 30m by 30m. I recently received some NetCDF climate data and when I used ArcMap to visualise the ...
Hornbydd's user avatar
  • 43.7k
1 vote
1 answer
157 views

Google Earth Engine - Pure pixels within farm boundaries

I would like to clip a MODIS image (coarse pixel) with a farm´s limits, but only for the pixels that are fully inside the limits. Looks like when using the "clip" function, it includes a ...
Alfonso de Lara's user avatar
1 vote
1 answer
1k views

Exporting high-resolution MODIS image from Google Earth Engine

I'm trying to extract from Google Earth Engine a large raster based on MODIS 250m data. However, when it gets sent to Google Drive, the resulting .tif has only a few pixels. Here's my code for ...
Holt Dwyer's user avatar
1 vote
1 answer
993 views

Export too large issue in Google Earth Engine

Here is the path to my script- https://code.earthengine.google.co.in/?accept_repo=users%2Fujavalgandhi%2FEnd-to-End-GEE&scriptPath=users%2FchakrabortySoumik95%2Ffirstprogram%3Asentinel%20Australia%...
soumik chakraborty's user avatar
0 votes
1 answer
22 views

Creating mosaic with filenames for each pixel in ArcGIS Pro

I am producing mosaics from multiple processed landsat scenes. The final product contains maximum values from several rasters. I would like to connect the value in each pixel of the mosaic to the ...
MESUIN's user avatar
  • 21
1 vote
1 answer
155 views

Identifying and replacing specific pixel in DEM using ArcGIS Pro

I have a DEM that has a handful out outliers, but I have no idea where they are within the DEM. I'm using ArcGIS Pro and I have used the outlier tool to try to identify the offending pixels, but there ...
redleg_64's user avatar
0 votes
0 answers
880 views

Basemaps are blurry/pixelated in ArcGIS Pro

I recently migrated from ArcMap to ArcGIS Pro and I am having trouble with the clarity of the basemap (whether World_Hillshade or World_Shaded_relief): It appears pixelated/blurry. I have imported the ...
MadMapMitrani's user avatar
0 votes
1 answer
165 views

Get list of longitude and latitude for non-null pixels in a region (Earth Engine)

I'm trying to extract the pixel's mid point longitude and latitude value in GEE firms dataset where a fire has occurred. I filtered the image collection ee.ImageCollection('FIRMS').filterDate('2020-...
GV_97's user avatar
  • 3
1 vote
1 answer
73 views

Reading and storing 1st pixels from multiple rasters

I want the code to read 1st pixel from a bunch of rasters (for eg. 1st pixel from 6 different rasters (having same extent and same number of pixels) and convert it into array followed by reading 2nd ...
surdeep's user avatar
  • 51
2 votes
1 answer
219 views

Calculate value per unit area from raster in QGIS

I have a raster (GeoTIFF) of number of people per pixel. I would like to convert this to a new raster of population per unit area. In other words, I would like to divide each value in my existing ...
Fab von Bellingshausen's user avatar
1 vote
0 answers
1k views

transform latitude and longtitude to pixel coordinate

I am trying to draw latitude and longtitude unit polygon on an image. Firstly I converted latitude and longtitude to pixel coordinate by these codes: #Coordinates of the image that was taken by ...
Wtow's user avatar
  • 11
1 vote
3 answers
1k views

Find raster pixel coordinates on shapefile polygon corners using Python

I have a raster file and shapefile with multiple polygons. How do I find raster pixel coordinates on shapefile polygon corners? Not the geographical coordinates based on CRS, but the pixel row and ...
g123456k's user avatar
  • 600
3 votes
1 answer
443 views

Creating/generating centroids point features from raster image in console in QGIS [duplicate]

I have a 1-band TIFF/raster file showing a value for each raster cell. I want to get those cell/pixel values of the TIFF extracted to a CSV file. I guess there are two ways of doing this. First, ...
Brigitte Colin's user avatar
0 votes
1 answer
110 views

How to stack layers (slope, curvature, aspect, etc) derived from DEM to form multi-band images in QGIS?

Made a DEM from Landsat imagery and derived the aspect, slope, curvature, TWI, etc layers (generic flood conditioning factors). I now need to incorporate these layers and feed them to a LSTM neural ...
Ada's user avatar
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