zeflash
22nd June 2007, 19:29
Hi
I'm looking for an application that being provided an image (or better yet a video) as the input could calculate the effective resolution, that is the lowest resolution you could resize the image to without starting to lose details.
Usecase scenario is when I want to reencode a sat recording of something that had a bad resolution to start with - it happens quite often.
I would assume from my (old) math classes that an app that could calculate the fourier transform of the image would then get the maximum frequency (horizontal or vertical) in the image. I believe there is a maximum intrinsic frequency that can be attained on a image of a specific size. If you then upscale that image, you would still end up with the same maximum frequency.
hmm... a sharpen would trick the FFT though, artificially adding high frequencies that weren't there in the first place.
So it might be not exactly how that would work, but I'm still looking for such an app if it exists :)
Any inputs?
I'm looking for an application that being provided an image (or better yet a video) as the input could calculate the effective resolution, that is the lowest resolution you could resize the image to without starting to lose details.
Usecase scenario is when I want to reencode a sat recording of something that had a bad resolution to start with - it happens quite often.
I would assume from my (old) math classes that an app that could calculate the fourier transform of the image would then get the maximum frequency (horizontal or vertical) in the image. I believe there is a maximum intrinsic frequency that can be attained on a image of a specific size. If you then upscale that image, you would still end up with the same maximum frequency.
hmm... a sharpen would trick the FFT though, artificially adding high frequencies that weren't there in the first place.
So it might be not exactly how that would work, but I'm still looking for such an app if it exists :)
Any inputs?