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38 votes
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Panchromatic Image association with high spatial resolution

Panchromatic images are created when the imaging sensor is sensitive to a wide range of wavelengths of light, typically spanning a large part of the visible part of the spectrum. Here is the thing, ...
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21 votes
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Free radar (SAR) satellite data

You can get Sentinel-1 data from scihub.esa. Requires only registration (And most likely, non-commercial use). As Sentinel-1 has just become operational the archive is not very extensive but should ...
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  • 422
19 votes

Image collection to Single Image in Google Earth Engine

// UPDATE: The easiest way is now toBands(). var merged = MOD1.toBands(); // For completeness, this is the iterate() way: var mergeBands = function(image, previous) { return ee.Image(previous)....
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14 votes
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Is the reflectance required to get the NDVI, for Landsat 8 images?

NDVI is defined for any two bands with near-infrared and infrared data (it is an empirical remote sensing index). As such, you can calculate it straight from the DNs. This is mostly OK if you are only ...
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  • 1,234
13 votes
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Adding excel table to QGIS print composer?

Save your excel file as CSV file go to Add Vector Layer in QGIS and navigate to your CSV file and load it In the print composer, go to Add attribute table, as you can see below: Select the Source ...
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  • 36.2k
10 votes

Seeking software for opening .img files?

GDAL supports .img format, both the basic Imagine and the extended Imagine (greater than 2GB), thus any software that utilizes GDAL drivers would support ERDAS Imagine. The most workable and well ...
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10 votes
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Is this satellite image of a blackout real?

NASA's "Black Marble" is not one satellite image, but a mosaic gathered over several weeks and heavily edited: The data was acquired over nine days in April 2012 and thirteen days in October 2012. ...
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  • 8,172
10 votes

Adding site photos to a print composer atlas in QGIS

It looks like so hard without any script. So I tried a solution like below. Sample data: margin and interval Script: Copy/paste the script to QGIS Python Editor. Set layout_name, layer_name, ...
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9 votes
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image segmentation of RGB image by K means clustering in python

I hacked together a solution for this and wrote a blog article a while back on a very similar topic, which I will summarize here. The script is intended to extract a river from a 4-band NAIP image ...
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9 votes
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How to Combine Two Image Overlaying Into One Image in Google Earth Engine?

Never mind my impatience, It was easy. I just convert them to image collection and then create mosaic of it! var combined_img = ee.ImageCollection([img_1, img_2]).mosaic();
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  • 253
8 votes
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Creating scatterplot with icons (svg or png) instead of points?

rasterImage draws a raster image at a given location and size. Below is a very rough example, which you can hopefully adjust to your needs. (I made up some location points, you would obviously have ...
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  • 3,204
8 votes
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Creating vector (with lines/polygons) from raster based on paper map in QGIS

Not automatization (strictly speaking), but one good helper tool would be Gimp Selection Feature plugin. It enables us to access Fuzzy selection tool of Gimp 2.10, and returns a polygon layer taken ...
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  • 29k
7 votes
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Is there a way to filter the colors out of an image?

Yes, there is a way to do that. In the symbology palette for the overlay raster, you can select the Display Background Value (R, G, B) _ _ _ as ___ option (see screenshot for a raster I have doing the ...
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  • 1,646
7 votes

image segmentation of RGB image by K means clustering in python

You could look at clustering in scikit-learn. You will need to read the data into numpy arrays (I'd suggest rasterio) and from there you can manipulate the data so that each band is a variable for ...
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  • 15.3k
7 votes

Adding site photos to a print composer atlas in QGIS

I know you mentioned you do not code, but your task may be cumbersome in click and drag software, because you want paired images-filenames; your goal may be accomplished with very few (8 to be precise)...
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  • 3,259
7 votes

Overlaying image with polygon shapefile in QGIS

Create a new layer, draw a polygon covering your area Difference geoprocessing tool, with your polygon as input, and the blocks as Overlay. Set a dark grey or black symbol Now you have a polygon with ...
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  • 51.2k
7 votes
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Noisy lines in all scenes for Landsat 7?

You should read about the Landsat 7 ETM+ SLC-off data This refers to all Landsat 7 images collected after May 31, 2003, when the Scan Line Corrector (SLC) failed. These products have data gaps, but ...
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6 votes

How to remove black box around georeferenced grayscale image in QGIS?

Try converting your file to another/the same format (Raster/conversion/translate(convert format).There you can define a value for "no data", which you can set to a number different than 0. Hope it ...
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6 votes

Free radar (SAR) satellite data

Only managed to find a couple of sources for SAR images and data: You can download SAR images from here which are mostly focused on ecological sites such as forests: You can download SAR samples ...
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  • 72.2k
6 votes

How to export the map in very high resolution

Make sure you're using a 64 bit build of QGIS. The limitation on exported composer sizes/DPI is much higher on a 64 bit build.
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  • 26.2k
6 votes
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Multi Temporal Images

Your understanding is correct. Obviously, you aren't limited to just two points in time, but that is only a minor variation. Multi temporal information is generally used for change detection, but it ...
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6 votes
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Otsu thresholding and classic image processing algorithms on radiometrically calibrated Sentinel-1 SAR images

Otsu's method does not really care about actual values since it tries to minimize the total variance within classes while maximizing the distance between the classes. So, you could just run Otsu on ...
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  • 166
6 votes

I cannot find full Sentinel-2 scenes

As far as I know, only tiled scenes are distributed since october on the ESA hub, so you will need to download all the tiles. Note that there are several alternative websites to download S2 data with ...
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  • 48.5k
6 votes
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I cannot find full Sentinel-2 scenes

I acknowledge in advance that the following links don't provide you with direct access to the full scenes, but I do think that they are useful resources for searching the Sentinel-2 archive. In ...
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  • 4,752
6 votes

Detect the coordinate reference system based on an image

What you want is the projection, not the coordinate reference system. You need to look at the lines of longitude and latitude and work out from their curvature what possible projections it might be. ...
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  • 51.1k
6 votes
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Using Open Google Earth cache file in QGIS?

I don't believe qgis is able to process Google Earth cache file. I advise you not to wast your time. Instead use SAS Planet alternative. It stores tiles locally as file:///D:/Software/SAS.Planet/...
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5 votes
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Georeference images together

you can either check "update georeferencing" or create a new rectified image using "rectify". These tools are in the drop down menu of th georeferencing toolbar.
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  • 48.5k
5 votes

Free radar (SAR) satellite data

JAXA have made global L-band SAR mosaics at 25 m spatial resolution available from the PALSAR sensor: http://www.eorc.jaxa.jp/ALOS/en/palsar_fnf/fnf_index.htm Registration is required to download ...
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5 votes

Free radar (SAR) satellite data

Sentinel-1 data is published as Open Data, with attribution, see licence here. Registration required. An API is provided. See Scientific Data Hub for details. Software is also provided to process ...
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  • 345
5 votes

Is there a way to filter the colors out of an image?

You can block out the "white" using a Mask function, through the image analysis window. Change NoData Interpretation to "All", and add values 0 (minimum) and 250 (maximum) to all bands in your raster. ...
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