3 ms·
Has ugly cyclic artifacts, would probably look better with mirrored extension (where the image is padded with flipped mirrored copies of itself). E.g. lowpass a
by nullc 12y ago
Has ugly cyclic artifacts, would probably look better with mirrored extension (where the image is padded with flipped mirrored copies of itself). E.g. lowpass and watch the sky bleed into the bottom.
Generally block transform techniques are not that interesting over a whole image because the signal isn't stationary.
- fensterbrett 12y agoI wonder whether our agreement upon the ugliness of Fourier artifacts (such as ringing) stems from a learned distaste for low quality image and video compression.
- nullc 12y agoForget preferences about the ringing, it's actually spilling light from one side of the image to the other, as a result of failure to pad. But yes, the ringing is ugly— and while there might be some learned elements here, the images are not periodic, they're mixtures of regions with different statistics, and it's inappropriate to spill one to the other.