Wikipedia:Reference desk/Archives/Computing/2021 April 23

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April 23

How to digitally fix NASA's tilted satellite images?

A significant portion of photos taken by Operational Land Imager (OLI) on the Earth observation satellite Landsat 8 that have been featured on NASA's website are, despite being rectangular, tilted and surrounded by dark areas. For example, this one, this one, and this one. How do I digitally fix them? I am using a Mac Os and GIMP is the image editing program I have. Will it be enough? StellarHalo (talk) 06:29, 23 April 2021 (UTC)

They've been rotated to put north on top. If you don't want that, yes, you can use gimp to fix it. Rotate the image, then trim the edges. There may be ways to automate this, but I'm not an image editing specialist. PiusImpavidus (talk) 08:41, 23 April 2021 (UTC)

You can also download the primary image products and other data - review Where to Get Data from the LandSat website.

The rotated images are already processed and are meant to be used in sort of a consumer-facing fashion: if you want data that is less-processed, it already exists, and it's more advisable to get it from source instead of trying to reprocess a downstream product (e.g. instead of attempting to "re-rotate" an already-rotated image, just locate the source image!)

Nimur (talk) 16:36, 25 April 2021 (UTC)