All Questions
537 questions
0
votes
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30
views
Automatically create a polygon of non-white borders from WTMS imagery
I was wondering how could you create a (multi) polygon representing the borders of non-white areas in a non-worldwide, online WTMS imagery automatically?
The WTMS in question: https://data.geopf.fr/...
0
votes
0
answers
21
views
Gdalwarp() based orthorectification using computed RPCs has distortions and artifacts
Orthorectifying an image with RPCs computed (using this library) based on a manually marked set of GCPs and an elevation model gives an output which looks something like what I've attached below ( ...
- 1
1
vote
0
answers
35
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
1
answer
72
views
Creating orthomosaic from UAV image
I was provided with UAV data consists of *.JPG and *aux.xml files. I tried to create an orthomosaic using ArcGIS Pro following this tutorial https://www.youtube.com/watch?v=I_hwOeft0n4&ab_channel=...
- 894
3
votes
1
answer
2k
views
Converting image data type from uint16 to uint8 using Python
I have a uint16 image, but when I want to convert this image to uint8 data type, I get bad results. I'm sharing my entry image and the result below. My image is a 3-channel RGB image.
original image: ...
- 75
4
votes
1
answer
506
views
What does "post to post" mean?
For example, when someone talks about the "post to post" elevation error of a DTM, what exactly are they referring to?
- 69
0
votes
0
answers
44
views
How to apply Empirical Line Method to UAS imagery for radiometric correction
I am correcting/calibrating multispectral UAS imagery using the Empirical Line Method using the raw digital number of 3 color panels (white, 18% grey, black). I found the slope and the intercept of ...
- 523
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
0
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0
answers
46
views
ENVI 5.6.2 HSV problem
I've used ENVI a lot in the past, but am a bit rusty. I have never ran into this problem and can't find anything online about it. I'm trying to do HSV sharpening with 3 band multispectral data and a ...
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
108
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
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 ...
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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?
...
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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
1
answer
224
views
What exactly is mask band according to GDAL? [closed]
The GDAL documentation for the translate function says:
Select an input band to create an output dataset mask band. But what exactly is a mask band?
band can be set to "none" to avoid ...
- 315
0
votes
0
answers
121
views
Wrong scale when exporting Google Earth Engine image as NumPy array
Relatively new to EE. I am trying to export a Google Earth image to a numpy array to run further processing. I have managed to convert the image to an array and have plotted it, but my plotted figure ...
- 1
0
votes
1
answer
896
views
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 ...
- 1
1
vote
0
answers
184
views
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/...
- 11
0
votes
0
answers
53
views
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
1
vote
1
answer
805
views
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 ...
- 113
1
vote
1
answer
369
views
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
2
votes
1
answer
142
views
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 ...
- 538
4
votes
1
answer
241
views
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 ...
- 1,218
0
votes
0
answers
111
views
Opening images layer stacked on ArcMap into ERDAS
I noticed that ArcMap can open almost anything but if I do a band combination or a supervised or unsupervised classification on ArcMap I cannot open it on ERDAS.
Is there a way around it?
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0
answers
164
views
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 ...
- 133
1
vote
4
answers
742
views
Most efficient way to perform rastercalculations with GeoTIFF and/or ErdasImagine files greater than 100gb
I have many GeoTIFFs ranging from 50-300gb and expect I'll have some even larger in the near future. I running a simple subtraction on a pair 77gb 1-band files, but I will also have similar 6-band ...
- 151
0
votes
2
answers
1k
views
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 ...
- 2,554
0
votes
1
answer
1k
views
Unsupported compression type in ERDAS imagine Software
Am trying to load a Landsat band but I keep getting the error of unsupported compression type, what might be the problem?
- 3
0
votes
1
answer
273
views
Doing Layer stack in ERDAS Imagine
I am trying to do "Layer Stack" of Landsat 5 Surface Reflectance image in ERDAS Imagine 2015 but every time i get output as black and white image. Though pixels have RGB values but still ...
0
votes
1
answer
88
views
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 ...
- 83
0
votes
1
answer
633
views
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
6
votes
2
answers
909
views
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, ...
- 8,208
1
vote
0
answers
316
views
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/...
0
votes
0
answers
102
views
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'...
1
vote
0
answers
200
views
How can I match the colors between the subset and the original image?
I have test subset using an AOI, and I have unchecked the "Ignore zeros in stats." option in the subset dialogue box. The difference in colors may have been cause by the histogram re-...
1
vote
1
answer
2k
views
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
1
vote
0
answers
50
views
Supervised classification in parts
I have an image from 1990 (res 30m, also clouds) for an area equal 2100km2 and when I performed the supervised classification, the software (ERDAS) confuses the classes that look similar. Is it ...
- 11
1
vote
1
answer
696
views
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 ...
0
votes
1
answer
1k
views
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-...
- 25
2
votes
1
answer
306
views
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 ...
- 2,190
1
vote
0
answers
216
views
Using ERDAS Imagine 2020 orthophotos
I am dealing with how to figure it out how to export an orthomosaic from my Agisoft Metashape because when I did the merge chunks there. When you merge there, it doesn't provide what I need because of ...
- 4,139
0
votes
1
answer
371
views
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 ...
- 507
1
vote
1
answer
365
views
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 ...
- 11
3
votes
0
answers
44
views
Empirical Line Method (ELM) in ArcGIS Pro [closed]
My images from 2017, 2018, 2019 and 2020 from the same area, recorded in the same time of the year, all look different regarding colour brightness, likely caused by atmospheric circumstances. As I ...
- 41
1
vote
0
answers
50
views
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?
- 141
1
vote
1
answer
209
views
Is it possible to display a gray color GeoTIFF in ERDAS as it simply occurs in QGIS?
I have several GeoTIFFs (gray color) to be imported in ERDAS, however after googleing I could not find a way to display that color gradient as it occurs in QGIS.
Below the GeoTIFF displayed in QGIS:
...
- 2,131
2
votes
0
answers
118
views
Do PNG files suffer performance for scaled read over ERDAS Imagine (.img) files?
So I have a 20 GB in size Raster Image in .img format. Though I will be examining the code, to find out why, I am AMAZED at how quickly QGIS renders the entire file in a scaled format, and prior to ...
- 21
1
vote
2
answers
588
views
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 ...
- 13
4
votes
4
answers
4k
views
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 ...
- 28.3k