Shulou(Shulou.com)06/02 Report--

This article mainly introduces what format png refers to, which can be used for reference by friends who need it. I hope you will learn a lot after reading this article. Next, let the editor take you to learn about it.

Png is a bitmap format that uses a lossless compression algorithm. The PNG format has three forms: 8-bit, 24-bit and 32-bit. Among them, 8-bit PNG supports two different forms of transparency, 24-bit PNG does not support transparency, and 32-bit PNG adds 8-bit transparent channels on the basis of 24-bit, so it can show 256 levels of transparency.

Png is a bitmap format that uses lossless compression algorithm. It is designed to replace GIF and TIFF file formats, while adding some features that GIF file formats do not have. PNG uses a lossless data compression algorithm derived from LZ77 and is generally used in JAVA programs, web pages, or S60 programs because of its high compression ratio and small file size.

The PNG format has three forms: 8-bit, 24-bit and 32-bit. Among them, 8-bit PNG supports two different forms of transparency (index transparency and alpha transparency), 24-bit PNG does not support transparency, and 32-bit PNG adds 8-bit transparent channels to 24-bit, so it can show 256 levels of transparency.

The numbers after PNG8 and PNG24 represent the maximum color values that can be indexed and stored in this PNG format. 8 represents the 8th power of 2, which is 256 colors, while 24 represents 2 to the 24th power, which has more than 16 million colors.

Characteristics

In small network communication, due to bandwidth constraints, under the premise of ensuring clear and lifelike pictures, it is impossible to use large bmp files on a large scale in web pages.

Lossless compression PNG files are compressed by the derivative algorithm of LZ77 algorithm, and the result is high compression ratio without data loss. It uses a special coding method to mark the repeated data, so it has no effect on the color of the image, and it is impossible to produce color loss, so it can be saved repeatedly without reducing the image quality.

The indexed color mode PNG-8 format is similar to the GIF image, which also uses an 8-bit palette to convert the RGB color image into an indexed color image. What is saved in the image is no longer the color information of each pixel, but the representative color number selected from the image, each number corresponds to a color, so the amount of image data is reduced, which is very beneficial to the spread of color image.

More optimized network transmission shows that PNG images are streamed in browsers, even though the interlaced images provide the viewer with a basic image content before being fully downloaded, and then gradually become clearer. It allows continuous reading and writing of image data, which is suitable for displaying and generating images in the process of communication.

Supporting transparency effect PNG can define 256transparency levels for the original image, so that the edge of the color image can be smoothly fused with any background, thus the jagged edge can be completely eliminated. This feature is not available in GIF and JPEG.

PNG also supports Alpha channel transparency for true color and grayscale images. Up to 24-bit true color images and 8-bit grayscale images are supported. Supports the transparent / translucent features of Alpha channels. Gamma calibration information that supports image brightness. Support for storing additional text information to retain information such as image name, author, copyright, creation time, comments, etc.

Thank you for reading this article carefully. I hope the editor can share what format png refers to is helpful to everyone. At the same time, I also hope you can support us, pay attention to the industry information channel, and find out if you have any problems. Detailed solutions are waiting for you to learn!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.