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Author Topic: Dark orthophotography export  (Read 1246 times)

Alterco

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Dark orthophotography export
« on: January 25, 2021, 12:16:11 PM »

Hi,

I use Metashape V1.6.5 b 11249

After exporting othophotographies in tiff format, they now appear very darker oppenned in my SIG software (QGIS 3.16).
The export in jpg format is ok. The exposition remains the same as in Metashape.

Should I correct my ortho before export ?

Thank you in advance for your answer.

AA

Alexey Pasumansky

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Re: Dark orthophotography export
« Reply #1 on: January 25, 2021, 01:35:46 PM »
Hello Alterco,

Can you send JPG and TIFF export results (for the same small area or of a low resolution ortho) to support@agisoft.com? Also please specify, which input image format is used (file format, bit depth).
Best regards,
Alexey Pasumansky,
Agisoft LLC

Alexey Pasumansky

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Re: Dark orthophotography export
« Reply #2 on: January 26, 2021, 02:11:37 PM »
Hello Alterco,

Thank you for sharing the related data.

I see that you are using 16-bit input images and the resulting orthomosaic is also 16-bit, if exported to TIFF format. Whereas JPG export is downsampled to 8-bit output.

As for the data display in QGIS, it seems that it automatically stretches 16-bit range for the channels according to the image band histograms. Please open the imported TIFF raster properties in QGIS, then go to Style tab and modify the values for RGB bands in the Band Rendering section to 0 - 65535 range for all the bands. I think it should give you visually similar result to JPG file.
Best regards,
Alexey Pasumansky,
Agisoft LLC