Questions tagged [digital-image-processing]

The field of raster image processing

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2
votes
2answers
125 views

Feature normalization (scaling) for Hyperspectral images

I have been straggling with the concept of feature normalization for the hyperspectral images. Respect to my problem I have attached a picture of my problem which clearly stands the issue which I have....
0
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0answers
13 views

Project masked image to a numpy array

I have two sources of data which I would like to compare. For one source (lets call it DS1) I have the pixel values as a matrix with shape (N,M). To compare it I download the corresponding sentinel ...
0
votes
1answer
45 views

Cloud mask for worldview

I'm using worldview imagery downloaded from gbdx and I want to apply cloud mask for it. It's preferable to use ready-made layer or some python module/tool to create it. The demand for the method ...
1
vote
1answer
16 views

Unable to activate analytic asset in satellite Imagery

I was trying to import the map of Melbourne. I was able to fetch the details from API coordinates but when i am trying to check the analytic asset status, it is returning inactive. # extract image ...
2
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0answers
61 views

Histogram matching in Google Earth Engine?

Does anyone know if there is a more GEE-friendly way of achieving this? I'm experimenting with S1 SAR image histogram matching in GEE and was wondering if foremost the code can be improved. Read here ...
1
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0answers
19 views

Generate multiple polygons based on JPEG image?

I have a number of image files depicting polygons (the original shapefiles are lost). Is there a way to automatically create new polygons in GIS, based on the form of the shapes visible in the image? ...
2
votes
1answer
62 views

QGIS raster calculator ^2 operation gives negativs results

I want to compare 2 same tiles at different dates. I use the raster calculator like this : (IR_band_frb - IR_band-aug)^2 But I get this result : The data range goes from -6049 to 4486 ... Why I ...
3
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0answers
840 views

Decision tree classifying of satellite image in R?

I want to classify satellite image in R using RWeka classifier, J48. I have a CSV file with the classes required, and raster data loaded in R. I am able to make the tree, however, I am not able to use ...
13
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4answers
10k views

Splitting .tif image into several tiles? [closed]

I have an image of size 1GB (.tif), with the width and height 94000x71680. I would like to chunk this image into 20000X20000 tiles so that I can process them. How can I do this?
3
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2answers
57 views

Detecting 12bit images in 16bit

Setting For the purpose of a machine learning algorithm I'm tying to automatically scale images of arbitrary bitdepth to unit interval, i.e. I want to map pixels from [0,2x] to [0,1] simply by ...
0
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0answers
26 views

How to get pixel per meter in MATLAB

I have a vector shapefile which is in unit of 'Meter' presenting boundary of overall Germany. I am converting it into raster format based on each pixel representing 300 Meters respectively. After ...
0
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1answer
370 views

Calculating band depth image for M3 data

I am working with chandrayaan M3 hyper spectral data. I need to create a band depth image for identifying mineral abundances. How do i calculate the continuum reflectance value for producing a band ...
2
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0answers
25 views

QGIS raster files not aligned due to different extent

I have a DEM file of building heights calculated from DSM-DTM in QGIS. Based on this DEM file, I generated a mask that indicates the presence of buildings in matlab. However, when I load the building ...
1
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0answers
60 views

What does cumulative count cut actually do?

I have a grayscale satellite image (16-bit image) which is dull (low brightness). When I apply cumulative count cut from 2 to 98 percent (Properties -> Min-Max Setting -> Cumulative count cut), it ...
1
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0answers
574 views

What causes this rainbow image artifact in Google Maps satellite imagery?

I discovered this "rainbow" over the Yellowstone River in Google Maps: View the site in Google Maps: https://goo.gl/maps/y6xETmY859M2 You can see a distinct red, yellow, and blue streak hovering ...
2
votes
1answer
55 views

Reading large image using GDAL?

I want too read large image. The image size is 92117 x 30313 pixels. So far I know cv2.imread can not read large size. How can I read using GDAL API?
0
votes
2answers
89 views

Relative Radiometric Normalization of multisensor Landsat Level 2 images using R

For my time series analysis, i need to use images of the three Landsat sensors (TM, ETM+ and OLI). I chose the already atmospheric corrected surface reflectance/Level-2 products. Due to the ...
1
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0answers
42 views

Assessing quality (accuracy and precision) of digital surface model (DSM)?

I have been trying to build digital surface model from stereo satellite images. I do some initial research of it, it looks like I have to go outside and manually measure the height of an object (...
9
votes
1answer
2k views

Ditch Extraction using LIDAR DTM (1m resolution)

I'm trying to extract ditches using the LIDAR DTM using the software eCognition but I am actually having a hard time since the paper where I based my workflow entitled "Ditches’ network extraction and ...
0
votes
1answer
21 views

Image Overlay 3D Adapt in Google Earth

When adding an image overlay (specifically a GeoTiff exported from QGIS), the image looks great until you turn on 3D buildings or terrain. These features pop through the image overlay, and disrupt the ...
3
votes
3answers
892 views

Extract values from raster based on points and pixels adjacent to the point

I have an issue. I have a set of points (n=~2000) and I would like to extract the pixel values from multiple rasters (a single-raster solution is also ok) for location of that point as well as that of ...
0
votes
0answers
24 views

Mapping a LinearFit to colors

Refering to EE>Examples>LinearFit (https://code.earthengine.google.com/598af3369de7a4845f0325030a66e0e1) I would like to check my understanding. On line 20 comment says: // Display trend in red/blue,...
5
votes
1answer
604 views

Verifying landsat reflectance values? [closed]

I am still beginner in Remote Sensing. I have asked a GRASS programmer to prepare for me Landsat reflectance values from raw DN values (1 scene per year from 1987 to 2013). I have proposed him (...
11
votes
2answers
821 views

Is it scientifically correct to pansharpen landsat reflectance product with pan band

I need to know if it is scientifically valid to fuse/pan-sharpen Landsat 8 surface reflectance products with pan band of that respective band? Landsat reflectance product details can be found at here. ...
1
vote
1answer
155 views

Iterative Mean of Means Infinite Loop for calculating H-t Index

I'm trying to create a function that will calculate an Ht-Index for Quantifying the Fractal or Scaling Structure of Geographic Features (but am new to R) which basically just finds nested means of ...
0
votes
0answers
11 views

Normalizing a single band of landsat 8 imagery w.r.t an adjacent one

We have 23 landsat 8 level 2 imageries which has to be mosaiced. Based on date, we have mosaiced individual bands (B1, B2, B3, B4, B5, B6) and now it's down to 5 imageries. But we are not getting a ...
2
votes
4answers
6k views

exporting metadata from gps camera to spreadsheet

I have a question involving exporting metadata from a GPS camera to an application such as a spreadsheet. In essence, I'm working with a significant number of images taken with a GPS digital camera. ...
0
votes
0answers
34 views

Matrix union in ArcGIS

How can I do matrix processing in ArcGIS or ERDAS Imagine? l have two different raster images for change detection. Matrix join same code filed information. In this video link already done matrix in ...
1
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0answers
78 views

Earth Engine: Function to generate daily image collection from 3 hourly

I am working with GLDAS-2.1 image collection. I would like to generate a daily image collection with max temperature, min temperature, mean temperature and sum temperature for each day from 3 hourly ...
0
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0answers
17 views

No Data Holes in Certain Tiling Scheme Levels in Mosaic Dataset Imagery Cache

I have a mosaic dataset containing three other mosaic datasets (one containing county imagery, one containing regional imagery, and one containing city imagery) I have them ordered by putting the ...
0
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0answers
164 views

Writing code to add calculated image to display in Google Earth Engine?

I wrote a code for Land Surface Temperature (LST) from Landsat 8 images in google earth engine. I have successfully calculated the following steps, NDVI, fractional vegetation (fv), emissivity (EM), ...
0
votes
1answer
885 views

Reading a 4 band image with rasterio (python)

I am trying to view a tif satellite image which has 4 bands. I want to remove the last band (NIR) and view the RGB image only, so I am trying to split the NIR from the rest of the image. Here is my ...
1
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0answers
82 views

Batch processing DTM with Hillshade in QGIS 3

I'm using the Hillshade tool from GDAL library [Raster analysis] in QGIS 3.4. I can't use the batch process with creative options like compress=LZW or profile=Geotif. It doesn't work. The tool works ...
1
vote
2answers
515 views

Pansharpen landsat mosaic in Google Earth Engine

Does anyone have a good way to pansharpen an entire mosaic of landsat 8 images? I would use the Panchromatic band (band 8). I have found tutorials on how to pansharpen a single image, but not for a ...
1
vote
0answers
42 views

Pre-Processing for multi-sensor Time series analyses based on Landsat Level 2 imagery

I downloaded TM, ETM+ and OLI Surface Reflectance Higher-Level Data Products (atmospheric corrected) based on L1TP Landsat images (radiometrically calibrated, orthorectified). I need to include images ...
3
votes
1answer
2k views

supervised classification

I am having a problem in creating new signatures in Signature Editor in ERDAS 2014. Whenever I click on the icon (i.e., after selecting the aoi), it shows an error which says "unable to open ...
3
votes
1answer
104 views

Performing Supervised Classification on Sentinel Image using ArcGIS Desktop?

Is it possible to perform supervised classification on Sentinel Satellite Image with the minimum error. I compared two raster, one being the manual classification of an area using Photoshop CS6 and ...
-1
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2answers
544 views

SCP QGIS sentinel 2 authorization error

I am using Qgis 2.18.16, when i tried to download sentinel 2 via SCP interface, I am getting following error: Authentication Required
5
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7answers
8k views

Failed to create signature file

I've no clue how to solve this issue in the exercise that I'm trying to perform. The point where I'm stuck is 4. "Create signature file as LandsatCompS.sgs". I've done what it says in the exercise. I ...
0
votes
1answer
27 views

Two different CRS somehow works? [duplicate]

I am overlaying some WGS84 (EPSG:4326) coordinates over a few DEM rasters with EPSG:102710 (NAD_1983_STATEPLANE_NEW_HAMPSHIRE_FIPS_2800_FEET) When they are these two different layer CRS the ...
0
votes
1answer
196 views

How to convert masks generated by rasterio to channel last mask

The problem is about using rasterio to generate mask from GeoJSON file which contains geographic coordinates. The function that I used is from: from rasterio.tools.mask import mask with rasterio....
1
vote
1answer
504 views

How to save an image stretch/enhancement in ENVI?

I am using ENVI 5.3.1 and viewing a georeferenced satellite image with a linear 1% histogram stretch applied to the entire image. When exporting the image with the current histogram stretch using File-...
12
votes
2answers
320 views

Ice type differentiation using satellite data

I would like to classify glacial area by categories of snow (if there is) and ice, but what's most important: between old ice and fresh ice. They have different properties that are possible to ...
7
votes
1answer
473 views

Counting rocks of different sizes on shoreline using ArcGIS Desktop? [closed]

I have a 5cm resolution geotiff image for a shoreline. I need to count the number of rocks in three classes (e.g., >6 feet, 3-6 feet, and <3 feet). I don't have any point cloud data. What will be ...
0
votes
1answer
48 views

Colorize radar imagery so it looks like optical imagery

Here is an imagery from a radar satellite Is it possible to colorize a radar image, so it looks like and enables the same kinds of analysis as for an image captured from an optical satellite (simple ...
3
votes
1answer
641 views

Retrieving exif tags from GeoTiff with GDAL?

I work on toolkit that automatically classifies data from a bunch of aerial cameras. Each camera uses geotagging to store position and time metadata in EXIF tags. When I use GDAL (I use version 2.0....
2
votes
0answers
2k views

Interpreting NDVI value on water?

There is a surreal thing on my NDVI images. NDVI values on lake is ranging from -0.04 to 0.7. (The lake surrounded by forest and has freshwater). Theoretically, negative value of NDVI is correspond to ...
1
vote
1answer
267 views

conditional statements for raster in R - land surface temperature

Im trying to calculate Land surface temperature estimating with Landsat 8 images, but i got stuck in one place and i cant move on. I m following split window algorithm. I calculated NDVI and I have ...
0
votes
1answer
100 views

Satellite image in ArcGIS darker than usual

This is one image from 2013 in some área. This is another image from 2014 in the same área, but darker. why? How can I display it like in 2013. Both are Landsat 8 images.
3
votes
2answers
2k views

Raster image thresholding using python

Can someone guide me for applying thresholding technique to input raster image using Python. I intend to extract impervious surfaces from a high resolution raster such as roads, sideways and ...