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This is because resampling filters with negative lobes like Mitchell–Netravali and Lanczos create ringing artifacts linearly even though human perception is non-linear and better approximated by gamma. (Emulating "stepping back," which motivates downsampling in linear light (gamma=1), does not apply when upsampling.)
Image scaling can be interpreted as a form of image resampling or image reconstruction from the view of the Nyquist sampling theorem.According to the theorem, downsampling to a smaller image from a higher-resolution original can only be carried out after applying a suitable 2D anti-aliasing filter to prevent aliasing artifacts.
Simple Fourier based interpolation based on padding of the frequency domain with zero components (a smooth-window-based approach would reduce the ringing).Beside the good conservation of details, notable is the ringing and the circular bleeding of content from the left border to right border (and way around).
Sample-rate conversion, sampling-frequency conversion or resampling is the process of changing the sampling rate or sampling frequency of a discrete signal to obtain a new discrete representation of the underlying continuous signal. [1]
The bicubic algorithm is frequently used for scaling images and video for display (see bitmap resampling). It preserves fine detail better than the common bilinear algorithm. However, due to the negative lobes on the kernel, it causes overshoot (haloing).
Each pixel is individually distorted, meaning outlines become unsmooth after anti-aliasing. Because the conversion to and from a linear format greatly slows down the process, and because the differences are usually subtle, most image editing software, including Final Cut Pro and Adobe Photoshop, process images in the gamma-compressed domain.
Increase (resample) the sequence by a factor of L. This is called Upsampling, or interpolation. Decimate by a factor of M; Step 1 requires a lowpass filter after increasing (expanding) the data rate, and step 2 requires a lowpass filter before decimation. Therefore, both operations can be accomplished by a single filter with the lower of the ...
Adobe Photoshop is a raster graphics editor developed and published by Adobe for Windows and macOS.It was created in 1987 by Thomas and John Knoll.It is the most used tool for professional digital art, especially in raster graphics editing, and its name has become genericised as a verb (e.g. "to photoshop an image", "photoshopping", and "photoshop contest") [7] although Adobe disapproves of ...