Enhancement Filters for JPG Files

JPG is the term coined by the Joint Photographic Experts Group, a group of experts that created, among others, a high quality image compression format, both in color and grayscale.

Therefore, we are facing the most common method when it comes to generating compression of photographic images.

Of course, it should be noted that the degree of reduction can be adjusted, allowing you to select the storage size and image quality.

Typically achieves a compression of one to ten with little noticeable loss in image quality.

One of the best aspects for its popularization is that these types of files are the most common on the internet and are supported by all browsers.

Sometimes you could find yourself in the situation that you need to apply a filter to enlarge a JPG image, for this, you can find several types of filters of a different nature, namely:

B-Spline

B-spline Interpolation method are a weighted set of basic functions for polynomial splines. That is, they are capable of reproducing a curve in segments defined by different polynomials.

Lanczos3

Filtering using the Lanczos3 algorithm or Lanczos3 resampling is the triple application of a mathematical formula. It can be used as a low-pass filter or used to smoothly interpolate the value of a digital signal between your samples.

Bicubic

Is an extension of cubic interpolation to interpolate data points on a two-dimensional regular grid. Using Lagrange methods, the interpolated surface is smoother than the corresponding surfaces obtained by bilinear interpolation or nearest neighbor interpolation.

Most image processing software has algorithmic interpolation filtering capabilities. With the disadvantage, that these softwares, in general, have a proprietary license.

There are also some online services that offer multiple algorithms to increase the size of an image. Such is the case of:

Online Image Enlarger

Below we have a sample of an image, enlarged using the three aforementioned algorithms