Questions tagged [digital-image-processing]
The field of raster image processing
266
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85
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Extract specific lat and long values in GeoTIFF file using Python
I have a GeoTIFF file and I have extracted the lat long values of each pixel in the file. However, I am looking to extract lat long of specific regions in the GeoTIFF rather than all of it. Here is ...
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19
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Assigning dates to a image collection which don't have any date properties attached to it
This is what I have done till now-
var image= ee.Image("users/rohithari1703/merged_IMD_raster_WGS84_collection");
//print(image);
var CHIRPS = ee.ImageCollection("UCSB-CHG/CHIRPS/...
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13
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Removal of Visible Flight Lines in Image Processing
I am processing MicaSense RedEdge multi spectral imagery in Agisoft Metashape and have some uneven coloration between the flight lines.
I've used "Calibrate Colors" tool and it hasn't seemed ...
- 21
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94
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What's the difference between bicubic interpolation and cubic convolution?
Our remote sensing professor recently introduced us to bicubic interpolation and cubic convolution, implying that they're basically the same. Now that I'm studying for the exam, I wonder: Is that ...
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1
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121
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Quickly read all sliding windows of large GeoTIFF
I'm currently using python and gdal to read sliding windows of a given size across very large 3-4 band (RGB/RGBA) GeoTIFFs with a nested for loop and gdal.Translate() to grab the data in a given ...
- 213
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1
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56
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How do I highlight specific pixels in an image using masking?
The two images below are the same.
In the images, the value of each pixel corresponds to a date in milliseconds.
In the top image, the pixels with the higher values - more recent date - are ...
- 348
4
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1
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151
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Removing dropped line using fourier transformation?
I've noticed a 'dropped line' in only one band of SPOT MS image, as seen similar to added example. By applying fourier transformation to the band in SAGA GIS, the dropped line can be clearly spotted ...
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66
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Digital Numbers to Top of Atmosphere Radiance for Landsat 8, which formula is suitable?
I read from the following article, https://www.mdpi.com/2072-4292/8/5/413 that in order to convert Landsat 8 Digital Numbers to TOA Radiance, equation (1) is used (attached image). For some other ...
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2
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265
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How to read and write raster matrix data with R (raster package and image processing)?
I'm using R for morphological operations on geo-rasters.
The packages mmnand and EBImage offer morphological operations. However they can't work with georeferenced rasters, but operate on a matrix (or ...
- 1,744
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15
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Piece Wise Linear Mode in Erdas imagine not showing
I was visualizing images in ERDAS imagine 2015 and got this message while trying to use Piece wise linear mode, what might be the problem and how do I meet the conditions specified in the error ...
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21
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Taking median or mean (pixel) for Soil Wetness index time series data
I have downloaded around 2100 raster files of Soil Wetness index raster derived using SMAP L-band Radiometer data, from 2015-2022 with 3 day composite update frequency
Data - https://www.mosdac.gov....
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1
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52
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Mapping Soil Sealing and Water Bodies
I am asked which bands of Landsat 9 (or 8) is best for mapping soil surface sealing and water bodies at higher resolution. The band available in Landsat 9 is as shown:-
From above band name; which ...
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1
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231
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After changed datatype from gdal.GDT_UInt32 to gdal.GDT_Byte, I had GDALDataset::GetRasterBand(2) - Illegal band #
I have several UAV images with 4 bands, and I wanna merge them. The data type of these images are all UInt8. I tried to use following code to store my merged numpy.
dataset = driver.Create(path, ...
- 11
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2
answers
411
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Applying HDR (high dynamic range) rendering in QGIS
I want to automatically (without manual adjustments) apply HDR (high dynamic range) rendering to Sentinel-2 satellite images so that the image can distinguish between very bright objects (e.g. clouds, ...
- 6,695
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169
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GEE Sentinel-2 Active Fire Detection - conditional image composition
I am working on Sentinel-2 image fire detection in Google Earth Engine. I would like to apply the Custom Scripts Active Fire Detection algorithm (https://github.com/sentinel-hub/custom-scripts/tree/...
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71
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Why is my image not showing and in my metadata it says that my band is 0?
I'm working on estimation chlorophyll-a using a Landsat 8 image on Google Earth Engine but my image is not showing, and in my metadata it says that my band is 0. I'm really really confused because I'...
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1
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874
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How do you check the attribute information of the tif image in QGIS?
Where can I check the brightness value (DN) of the image stored as 'tif format' in QGIS? What is the way to add it to the attribute table?
Current progress:
Coordinates are assigned to each pixel of ...
- 467
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1
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434
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Google Earth Engine Exported GeoTIFF is blank - how to export my code as an RGB for Ai or Ps
I am trying to export my classified map layer (classified_image) as a GeoTIFF, JPG or PNG (Any format that can be viewed on Illustrator or Photoshop). Geolocation does not matter, I just need the ...
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1
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765
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Landsat 8 Collection 2 (C2) Level 2 Science Product (L2SP)
I am exploring data sources for land surface temperatures (LST) for summer 2021. From Landsat 8 Collection 2 Surface Temperature (https://www.usgs.gov/core-science-systems/nli/landsat/landsat-...
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1
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208
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Finding the correct aspect ratio from image
I'm trying to put an image over my map.
I know the correct bounding box of it, but when I load it, I see it doesn't fit correctly in the map.
Just for curiosity, I cut a piece of map of same region ...
- 2,040
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150
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QGIS: Shifting ortophotos by some meters to equalize the mismatch/offset/incongruence with satellite imagery
I got several true ortophotos from environmental authorities. These photos should serve as reference for classifying pixels of satellite records.
Though the authorities told me that the georeferencing ...
- 477
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1
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214
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Export image from GEE without accidental resample?
I'm trying to export an ALOS DSM raster at its native 30m resolution for a specific region derived from a centroid in GEE. I'm noticing, however, that when I open the raster in ArcGIS there is a clear ...
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44
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Correcting effect of solar elevation angle in tagged areas for Landsat 8 L1T images using ENVI
Someone said the L1T images did not correct the effect of solar elevation angle.
I want to know how can I get the parameters for doing such correction in ENVI?
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2
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351
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Google Earth Engine: "Parameter 'index' is required" error when mapping to an Image Collection
I am trying to apply a distance function to a collection of masked images, but am receiving a "Parameter 'index' is required" error. I've found answers for other "Parameter 'xyz' is ...
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4
answers
3k
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What is lost when converting 12 bit imagery to 8 bit?
SPOT 6/7 satellite imagery is captured with a dynamic range of 12 bits per pixel per channel (ref). However almost all of the SPOT imagery I have seen in use has been 8 bits per channel, and split ...
- 28k
2
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1
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310
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How to remove banding in Sentinel-2 imagery over water?
In several L2A Sentinel-2 images, I've seen an angular banding effect over water bodies. Another user thought that these seam effects were caused by aerosol scattering affecting each of the S2 MSI ...
- 243
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4
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767
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Should I always choose Sentinel-2 atmospheric-corrected imagery?
Sentinel-2 imagery is available in the default L1C form, or in the atmospheric-corrected L2A form.
I haven't been able to find a L1C - versus - L2A comparison that would provide the pros and cons of ...
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434
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Generate list of legend's RGB colors and values in ArcGIS
I am writing a node/typescript app that analyzes raster data. It uses leaflet and esri-leaflet quite a bit (modified to work server-side). For a given map bounds, it can download a raster image from ...
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1
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589
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Generating Hough transform (Hough line transformation) of binary image using QGIS
How do I generate a Hough transform (Hough line transformation) of a binary image in QGIS?
I tried in GRASS and I got Error: unable to fetch interface description for command
I found from the link: ...
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1
answer
1k
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Applying Otsu thresholding method to raster in QGIS
How can I apply Otsu’s threshold method to a Raster in QGIS for reduction of a gray level image to a binary image?
- 537
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2
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3k
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Computing Excess Green Vegetation Index (ExG) in QGIS [duplicate]
I have to process the image for Sugarcane row detection and extraction.
Sample image is accessible from the link: https://github.com/AndresHerrera/croprows_generator_pa_v2/tree/master/droneimages
I ...
- 537
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1
answer
117
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Designing a Low Pass Filter
How can I design a similar Low Pass Filter as given below which takes into account only 4-connectivity and ignores the pixels that complete 8-connectivity?
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48
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LPF and HPF filters in ENVI
Since we know about convolution filter in image processing, it is basically a matrix applied to an image and a mathematical operation comprised of integers and it works by determining the value of a ...
- 151
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37
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Spectral signatures difference between a raw image and an atmospherically corrected image
I did atmospheric correction of Landsat 5 image by Quick atmospheric correction method(QUAC), now I want to compare atmospheric corrected spectral signatures from ENVI QUAC with the input spectral
...
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2
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1
answer
390
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Radiance and Raw Image difference after Radiometric calibration
I have done Radiometric calibration on Envi 5.3 and got the output of my input Landsat 5 image.
What is the difference between the raw image and the radiance image and why is this value of radiance ...
- 151
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121
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Using r.thin in GRASS
I am new to GRASS GIS. I need to run my program with the r.thin command, and I will not get any results as I proceed according to the program. My map is a png image in 2 bits.
How do I execute this ...
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172
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Landsat 8 band combinations aren't appearing the way they should in ArcMap
I did all the right steps of combining 7 of Landsat 8 bands into one .tif in ArcMap but the combinations aren't just appearing the way they should, attached picture related.
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1
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56
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Mask area of GeoTIFFs surrounded by 0 Data
I've a larger amount of GeoTIFFs which basically look like:
The area of interest is the rectangle in the middle.
Black shows 0-Data.
My goal is to fill the left and right sided areas (round) with 0-...
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0
answers
18
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Statistics from one image to another in Google Earth Engine
I now have two images of the same place, image1 stores image values and each pixel on image 2 stores time (jday).I want to count the sum of image values of image1 at the same time point on image2.For ...
- 109
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1
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121
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Combining single cloud-masked images using Google Earth Engine
I am trying to calculate the mean pixel values of three Sentinel-2 images, all of which I have cloud masked separately. They all have small areas of cloud but in different places. I assumed that when ...
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572
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Problem Visualizing and Downloading LANDSAT 5 Images With Google Earth Engine
I am new to GEE. I'm working with Landsat images. First, visualizing them in the map, then downloading them and working with them afterwards in QGis 3.6 to obtain certain indexes (NDVI, NDWI, Wetness) ...
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127
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Increasing Resolution of Image By Splitting Image Pixel into Smaller Pixels | Google Earth Engine?
I have two MODIS satellite images with same custom band, one of 1000m/px resolution and other of 250m/px. I want to compute their mean 'image' and display as map layer.
My current way of achieving ...
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71
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Pixel-based image classification (Orthoimage or Raw image?
I am studying image classification and wanted to produce some land cover maps.
However, i can not seem to find resources that states whether you need to geometrically correct (orthorectification) your ...
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vote
1
answer
201
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Orfeo toolbox batch processing
I want to process Sentinel 2A images using another tool that is not SNAP. The later is very slow and crashes each time. I was recommended the Orfeo toolbox. I installed it on QGIS. I have 58 S2A ...
- 411
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143
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Band Compositing
This is probably a trivial question, but is it possible to create band composites using bands of different resolutions (10m, and 20m)? I tried that and exported the resulting rasters to JPEG and it ...
- 411
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1
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355
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Image (band) interpolation
I have a set of sentinel 2A images. I eliminated those that contained too many clouds, and then I created a cloud mask using cloud probabilities and Otsu thresholding method to eliminate cloudy pixels ...
- 411
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145
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Rasterio doesn't display the differnet bands of image
I have one raster which has three different bands.
The two first bands look like this (in qgis):
and the third band looks like this ( missing values in some places:
The three bands sit on top of ...
- 1,920
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1
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242
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Processing and classifying satellite images using Python [closed]
I wish to process and classify Sentinel2-L2A images using solely Python (Google Colab). Is it possible to do such a thing, and if so, what libraries should I use?
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1
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2k
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"Spatial join" between raster and shapefille- give raster the shapefile values with python
I have raster which has NDVI values .In addition, I have shapefile(geopandas) on top of this raster but it doesn't fully covers the raster (illustration):
the shapefile has column which contain data ...
- 1,920
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2
answers
60
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Transforming featureCollection back to an actual image
I am about to finish my calculations made on the feature that I have extracted from NDVI images.
Each image was originally transformed into a list (by the scale of 10) and extracted to a CSV file.
One ...
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