# I am the Watcher. I am your guide through this vast new twtiverse.
#
# Usage:
# https://watcher.sour.is/api/plain/users View list of users and latest twt date.
# https://watcher.sour.is/api/plain/twt View all twts.
# https://watcher.sour.is/api/plain/mentions?uri=:uri View all mentions for uri.
# https://watcher.sour.is/api/plain/conv/:hash View all twts for a conversation subject.
#
# Options:
# uri Filter to show a specific users twts.
# offset Start index for quey.
# limit Count of items to return (going back in time).
#
# twt range = 1 6
# self = https://watcher.sour.is/conv/3tslmiq
If I have an image that has clearly been naïvely upscaled, is there a program that can reasonably reliably tell me what the "true" size is?
If I have an image that has clearly been naïvely upscaled, is there a program that can reasonably reliably tell me what the "true" size is?
@anth From my classes of image processing, I can recall that's not an easy problem to solve...
Why do you want to know the true/previous size ?
@anth In general I don't know that it's possible, but this might be a decent place to start. One sort of obvious way to detect upscaling is to run DFT (discrete Fourier transform) over (portions of) the image and see whether there is an obvious cutting-off point in the frequency domain that would signal a bandpass had ocurred. Fully-detailed images would have frequencies in all bands, but upscaled images would be missing the highest-frequency variations. Of course that'd depend on what exactly the image was--some natural images don't have high-frequency variations either. Anyway, good luck!