What is the format of png files?

PNG is a common image file format, whose full name is "Portable Network Graphics". It is a lossless compression format designed to replace the JPEG and GIF formats commonly used in the past. The PNG format was created in 1995 by graphic designer Thomas Boutell and grew in popularity over the following years.

The PNG format is characterized by supporting high-quality image compression while retaining image details and color information. Compared with JPEG format, PNG format is lossless compression, which means that no data is lost during the image compression and decompression process. This makes the PNG format excellent in scenarios where image editing and production require a lot of detail and accurate color, such as bitmap images (such as icons, logos, etc.), screenshots, artistic design works, etc.

Compared with GIF format, PNG format has higher color depth and transparency support. The PNG format supports 24-bit true color images, while GIF only supports 256 colors. In addition, the PNG format also supports transparency features, which can achieve transparent background and translucent effects of images. This makes the PNG format very useful in design and web production that require a transparent background, such as icons, graphics, logos, etc.

In addition to lossless compression and transparency support, PNG comes in three variants: single image, multiple images, and animated images. A single image means that it contains only one static image, and multiple images means that it contains multiple static images in the same file, and each image has its own index. Animated images are continuous image sequences composed of multiple frames, which can create simple animation effects.

Although the PNG format has many advantages, there are also some limitations. First, because PNG uses lossless compression, image files are generally larger than those in JPEG or GIF formats. This means that the PNG format takes up relatively more space and bandwidth in terms of storage and transmission. Secondly, the PNG format does not support CMYK color mode, which is a common color mode used for printing. Therefore, when the image needs to be used for printing purposes, it is usually necessary to convert the PNG format to other formats that support CMYK mode, such as TIFF or EPS.

Overall, PNG is a very useful and common image file format. Its high-quality lossless compression, transparency, and multiple variants make it widely used in image editing, web page production, and art design. Although it has some limitations, the PNG format is still one of the preferred image formats by many people.

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