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ultramango / gear360reveng

Some internal information on Samsung Gear 360
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Are cameras factory calibrated? #8

Open utack opened 6 years ago

utack commented 6 years ago

Something I was wondering about: Do you think there is factory calibration data written into the EXIF, about how lenses are assembled? The app does a really good and quick job stitching with minimal "borders" where image content does not match, tbh I'd be surprised if it could do so quick and well on a phone CPU, without getting some calibration data how images line up

Is there a way we could do a "large scale comparison", which binary sections of the jpg beginning match between all images taken with a single camera, and then another one which of these parts also differ with all other cameras, to find out if there is camera specific data in the images?

usumfabricae commented 6 years ago

It seems to me that stitching is managed before writing the image to the sdcard (directly in memory) by libdi-arc-imagestitch.so I think it reads data from internal camera memory (CFisheyePanorama::loadCalibrationDat) maybe stored during the factory building process? I saw something interesting looking at prefman

ultramango commented 6 years ago

First I kind of doubted that they do it - after the revelation with loadCalibrationDat - they could have some kind of pattern in front of the lenses and based on that calculate proper transformation for both lenses.