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Author Topic: Calculations/Formulas for Blending Modes & Pixel Upscaling?  (Read 3798 times)

aggieair

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Calculations/Formulas for Blending Modes & Pixel Upscaling?
« on: December 04, 2014, 09:02:52 PM »
First, I would like to know what the pixel calculations are for each of the blending modes:

Mosaic (default)
Average
Max Intensity
Min Intensity

Mainly the difference between the first two, but overall I just don't want to make any assumptions!



Secondly, when you export a mosaic or DEM and you increase pixel size, what "upscaling" method is it using?

Alexey Pasumansky

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Re: Calculations/Formulas for Blending Modes & Pixel Upscaling?
« Reply #1 on: December 09, 2014, 01:01:17 PM »
Hello aggieair,

Mosaic – images are decomposed into high frequency and low frequency components. A weighted average is calculated separately for low frequency and high frequency components (with different weights), which are subsequently combined back into final image.
Average – simple weighted average of overlapping image colors.
Max Intensity – color from the image with the highest intensity at the corresponding point is used (without any changes).
Min Intensity – color from the image with the lowest intensity at the corresponding point is used (without any changes).


Currently PhotoScan uses simple bilinear interpolation.
Best regards,
Alexey Pasumansky,
Agisoft LLC