image banding

[emaxwell]

I am having an issue with pronounced image banding. The initial problem was with adjacent flights flown in opposite directions. As a test I removed every other flightline and the image looked good in photoscan, but when I exported an Ortho without using color correction, I had a similar banding issue. Exporting with color correction seems to help.
Why am I seeing banding from flights flown in different directions, ( I should not have to throw out half my imagery)?
And why, when the banding is not present in the original file does it appear in the ortho if I don't use color correction?

Thanks

[Marcel]

Is the camera pointing straight down, or does it have a small angle? If the camera has a small (sideways) angle then the difference could be because of the specular reflection of the sun. Sand and soil look pretty matte/non-reflecting, but they do have a bit of specular reflection.

The effect is probably very even over the whole image, so you could also try sorting the images into rows, and correcting the brightness manually per row in Photoshop.

[emaxwell]

the camera has a small angle because the UAV flies slightly nose up. The banding appears regardless of flight direction, (north-south vs east west). We get a similar issue over heavily forested areas where the ground itself is not evident.

[andyroo]

I saw the same artifacts without color correction in one of my flights too. I think it has to do with the camera angle relative to the sun, just like taking a pic with someone with the sun behind them or behind you makes a large difference in image brightness, so does even a slight angle toward the sun rather than away from it.

Anyway, my solution was to export with color correction and that seems to nicely normalize exposure/brightness/whatever

Andy