Shulou(Shulou.com)06/03 Report--

Today, I would like to talk to you about what JEPG is, many people may not know much about it. In order to make you understand better, the editor has summarized the following contents for you. I hope you can get something from this article.

JPEG Joint Photographic expert Group is a standard for continuous-tone still image compression. The file suffix is jpg or jpeg, which is the most commonly used image file format. It mainly adopts the joint coding method of predictive coding, discrete cosine transform and entropy coding.

Performance of JPEG

The performance of JPEG, measured by the ratio of quality to bit rate, is quite superior. Its advantages are:

It supports extremely high compression ratio, so the download speed of JPEG images is greatly accelerated.

It can easily deal with 16.8m colors and can reproduce full-color images well.

In the process of image compression, the image format allows free choice between the minimum file size (lowest image quality) and the maximum file size (highest image quality).

The file size of this format is relatively small, the download speed is fast, and it is beneficial to transfer when the bandwidth is not "rich".

The disadvantages of JPEG are:

Not all browsers support inserting various JPEG images into web pages.

When compressing, the quality of the image may be lost, so it is not suitable to use this format to display high-definition images.

JPEG is impressive because of its low complexity and long use time. Here are several levels given by JPEG as criteria to measure the effectiveness of compression coding for 8-bit-per-pixel moderately complex images:

0.25 bit / pixel ~ 0.5 bit / pixel; medium ~ good, enough to meet some applications.

0.5 bit / pixel ~ 0.75 bit / pixel; good ~ good, enough to meet many applications.

0.75 bits / pixel ~ 1.5 bits / pixel; excellent enough to meet most applications.

1.5 bits / pixel ~ 2.0 bits / pixel; it is difficult to distinguish from the original image, which is enough to meet most applications.

> 2.0 bits per pixel; almost perfect, satisfying almost all applications.

The bit per pixel (bit/pixel) is defined as the total number of bits of the compressed image (including the chrominance component) divided by the number of samples of the luminance component.

After reading the above, do you have any further understanding of what JEPG is? If you want to know more knowledge or related content, please follow the industry information channel, thank you for your support.

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