Questions tagged [digital-image-processing]

The field of raster image processing

Filter by
Sorted by
Tagged with
0 votes
0 answers
10 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 ...
R. Ian Cunningham's user avatar
0 votes
0 answers
11 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 ...
DMAGAS SENAVIRATHNA's user avatar
0 votes
0 answers
29 views

What do the values mean in surface reflectance/surface temperature bands Landsat 8/9 OLI/TIRS C2 Level 2?

I am trying to make a heat risk index using Landsat8 but I am having a bit of trouble with understanding the basics or operating remotely sensed imagery. I downloaded the band 10 of Landsat 8 because ...
noobshacks76's user avatar
0 votes
0 answers
28 views

How to have a good rendering with mdenoise - DTM LiDAR denoising

I'm trying to generate a clean slope map from a LiDAR DTM. Due to LiDAR high resolution, the slope map is full of noise. So to do this, I use mdenoise library. It works quite well but it generates ...
Tim's user avatar
  • 83
0 votes
1 answer
71 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 ...
MoritzMoreira's user avatar
0 votes
0 answers
67 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 ...
Neo96's user avatar
  • 1
0 votes
1 answer
526 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 ...
Vivek's user avatar
  • 1
1 vote
0 answers
145 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/...
Anisha's user avatar
  • 11
0 votes
0 answers
40 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 ...
Caroline's user avatar
1 vote
1 answer
268 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 ...
Pixelcode's user avatar
  • 113
1 vote
1 answer
269 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 ...
mrgeo's user avatar
  • 213
2 votes
1 answer
110 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 ...
Iago Mendes's user avatar
4 votes
1 answer
183 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 ...
Rex's user avatar
  • 1,198
0 votes
0 answers
103 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 ...
Chris's user avatar
  • 123
0 votes
2 answers
824 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 ...
Honeybear's user avatar
  • 2,386
0 votes
1 answer
76 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 ...
Pushkar's user avatar
  • 83
0 votes
1 answer
411 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, ...
Raymond10153's user avatar
6 votes
2 answers
683 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, ...
Comrade Che's user avatar
  • 7,051
1 vote
0 answers
245 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/...
jakubslesinski's user avatar
0 votes
0 answers
92 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'...
Martanti Aji Pangestu _'s user avatar
1 vote
1 answer
1k 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 ...
bsg's user avatar
  • 467
1 vote
1 answer
574 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 ...
Riad El Soufi's user avatar
0 votes
1 answer
918 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-...
Monica Pena's user avatar
2 votes
1 answer
262 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 ...
Magno C's user avatar
  • 2,120
0 votes
1 answer
254 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 ...
jaysigg's user avatar
  • 497
1 vote
1 answer
314 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 ...
slidekel's user avatar
1 vote
0 answers
47 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?
tunar's user avatar
  • 141
1 vote
2 answers
493 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 ...
Jay Schoen's user avatar
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 ...
matt wilkie's user avatar
  • 28.2k
3 votes
1 answer
435 views

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 ...
Graham S's user avatar
  • 263
12 votes
4 answers
1k views

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 ...
Stu Smith's user avatar
  • 8,192
2 votes
1 answer
492 views

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 ...
Seth Lutske's user avatar
4 votes
1 answer
710 views

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: ...
HansrajR's user avatar
  • 537
-1 votes
1 answer
1k views

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?
HansrajR's user avatar
  • 537
5 votes
2 answers
4k views

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 ...
HansrajR's user avatar
  • 537
2 votes
1 answer
123 views

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?
Autodidact's user avatar
0 votes
0 answers
59 views

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 ...
Autodidact's user avatar
1 vote
0 answers
45 views

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 ...
Autodidact's user avatar
2 votes
1 answer
545 views

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 ...
Autodidact's user avatar
0 votes
0 answers
165 views

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 ...
saeed's user avatar
  • 1
0 votes
0 answers
187 views

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.
Mohammed Imad Eddine Alliouche's user avatar
1 vote
1 answer
74 views

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-...
Anatol's user avatar
  • 475
2 votes
0 answers
20 views

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 ...
YYu's user avatar
  • 109
0 votes
1 answer
149 views

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 ...
em.popcorn2's user avatar
-1 votes
1 answer
735 views

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) ...
AlbertoH's user avatar
0 votes
0 answers
149 views

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 ...
Waleed93's user avatar
  • 322
0 votes
0 answers
77 views

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 ...
missgeo's user avatar
1 vote
1 answer
232 views

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 ...
Rim Sleimi's user avatar
0 votes
1 answer
165 views

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 ...
Rim Sleimi's user avatar
0 votes
1 answer
384 views

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 ...
Rim Sleimi's user avatar

1
2 3 4 5 6