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Messages - DoubleJ

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General / Re: micasense rededge reflectance calibration.
« on: May 10, 2023, 12:21:21 AM »
Given that most of the images appear to be under cloud shadow, my advice would be to use the "Assign Images" tool to try to exclude any images with direct light (sunny images). To my knowledge, the downwelling light sensor works best under diffuse light so that is your best chance at getting a consistent calibration across the map.

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I don't see  "Create multispectral cameras from files as bands" anywhere but I'm also having problems loading photos.

If I choose "Add Folder" it will only load the 'green' bands.

If I choose "Add Photos" then filter only '*.tif" images or even put all the tif images in a separate folder, I can only load all monochrome bands if I choose "Single cameras". If I select "Multi-camera System" then only the 'green' bands will load into the chunk.

I don't think Metashape is functioning properly for Mavic3 multispectral unless you are only trying to process the Bayer array RGB captures.

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General / Re: Phantom 4 Multispectral
« on: August 14, 2020, 07:15:04 PM »
Sometimes the calibration panel works well but other times not so much. For me, it mostly impacts some blue band captures.

One big issue is that the P4M has a different definition of vignette correction in comparison to Micasense so DJI is discussing this and trying to find the best way to solve the issue.

Given the vignette issue, I suspect that some other metadata values may not have a one-to-one correspondence with MicaSense metadata. Also, given that vignette correction is not successful, and it is part of the calibration panel routine, the calibration panel would need to be in the center of the frame so it isn't in a dark spot in the image. I'm not sure if anything else in the calibration routine "breaks" due to the vignette issue. The vignette can be solved with "calibrate colors" later on in processing, but the DJI metadata parameters might need to be translated to MicaSense equivalent, or the Agisoft code might need to be modified for the P4M.

Also, for troubleshooting this, I recommend against trying to use the sun sensor and just stick to panel calibration.

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