नमूने-का-चुनना इसके अंग्रेजी अर्थ का उदाहरण

From the standpoint of digital signal processing, the scaling of raster graphics is a two-dimensional example of sample-rate conversion, the conversion of a discrete signal from a sampling rate (in this case the local sampling rate) to another.

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.

In the case of up sampling, a reconstruction filter takes the place of the anti-aliasing filter.

Sinc and Lanczos resampling .

Sinc resampling in theory provides the best possible reconstruction for a perfectly bandlimited signal.

In practice, the assumptions behind sinc resampling are not completely met by real-world digital images.

Lanczos resampling, an approximation to the sinc method, yields better results.

Bicubic interpolation can be regarded as a computationally efficient approximation to Lanczos resampling.

When down scaling below a certain threshold, such as more than twice for all bi-sampling algorithms, the algorithms will sample non-adjacent pixels, which results in both losing data, and causes rough results.

The trivial solution to this issue is box sampling, which is to consider the target pixel a box on the original image, and sample all pixels inside the box.

Another solution to the downscale problem of bi-sampling scaling are mipmaps.

If the ratio between input/output propagation distance and Rayleigh length returns \le 1 the surface wavefront maintains itself nearly flat along its path, which means that no sampling rescaling is requested for the phase measurement.