I would guess you usually see 8bit RGB images because that is what your monitor can display. What is lost is a deeper question, per channel you have to squeeze the original [0 - 4095] pixel value range per channel down to [0 -255], and there are lots of ways to do it. The problem is sometimes called tone mapping <https://en.wikipedia.org/wiki/Tone_mapping#:~:text=Tone%20mapping%20is%20a%20technique,a%20more%20limited%20dynamic%20range.>. Planet had a nice blog post describing how they manually convert their imagery to 8bit RGB here <https://www.planet.com/pulse/color-correction/>. If you were using the imagery for analytic things (e.g. converting pixel values to reflectance) you'd probably not want the 8bit product.
To get GDAL in the mix, note that gdal_translate can do simple tone mapping for you: https://gdal.org/programs/gdal_translate.html#cmdoption-gdal_translate-scale Patrick On Wed, Mar 17, 2021 at 3:23 PM <matt.wil...@yukon.ca> wrote: > SPOT 6/7 satellite imagery is captured with a dynamic range of 12 bits per > pixel per channel (ref <https://eos.com/spot-6-and-7/>). However almost > all of the SPOT imagery I have seen in use has been 8 bits per channel, and > split into RGB natural colour (Bands-321) and Near-infrared-RG false colour > (Bands-432). What information is lost in this 12 to 8 bits conversion? > > I'm wondering if we should be altering our request for purchase > specifications to deliver the full bit depth. > > *Although I'm referencing SPOT imagery specifically the question is > general and really applies to any satellite or sensor system.* > > Cross-post: > https://gis.stackexchange.com/questions/390315/what-is-lost-when-converting-12-bit-imagery-to-8-bit > > > > > > *Matt Wilkie* > > Geomatics Analyst > > Environment | Technology, Innovation and Mapping > > T 867-667-8133 | *Yukon.ca <http://yukon.ca/>* > > *Hours: 08:30-16:30, Tue-Wed: Office, Thu-Fri: Remote.* > > > _______________________________________________ > gdal-dev mailing list > gdal-dev@lists.osgeo.org > https://lists.osgeo.org/mailman/listinfo/gdal-dev >
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