Calculations/Formulas for Blending Modes & Pixel Upscaling?

[aggieair]

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]

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.