History of the Portable Network Graphics (PNG) Format

PNG (Portable Network Graphics) is a lossless image compression file format. PNG has nearly completely superseded the formerly popular Graphics Interchange Format (GIF).

A PNG file, like a GIF, is lossless compressed, which means that when the file is decompressed during viewing, all picture information is recovered. A PNG file isn’t meant to take the place of the JPEG format, which is “lossy” but allows the author to choose between file size and picture quality while compressing the image. An image in a PNG file is typically 10 percent to 30% more compressed than one in a GIF file.

png image 15478File format of PNG

The PNG format has the following features:

  • Not only may a single color be made transparent, but the degree of transparency, known as opacity, can also be adjusted.
  • Images interlacing is supported, and the image develops quicker than in the interlaced GIF format.
  • Gamma correction allows you to adjust the color brightness of a picture to meet the requirements of certain display manufacturers.
  • True color images, as well as the palette and grayscale formats offered by the GIF, can be stored.


The most widely used image file formats on the web are JPEG and PNG, however there are distinctions between them.

In 1986, the JPEG (Joint Photographic Experts Group) was created. This picture format uses very little storage space and uploads and downloads quickly. Because JPEGs can display millions of hues, they’re ideal for real-world pictures like photos. They’re great for publishing on social media and look great on websites.

When a file is converted to a JPEG, some quality is lost or compromised because JPEG is “lossy,” which means that when data is compressed, unneeded (redundant) information is permanently deleted from the file.

Unless the image contains text, requires transparency, is animated, or would benefit from color changes, such as logos or icons, JPEG is the default file format for posting images to the web.

JPEGs, on the other hand, aren’t suitable for pictures with little color information, such as interface screenshots and other basic computer-generated visuals.

The fundamental benefit of PNG over JPEG is lossless compression, which means there is no quality degradation when a file is opened and saved several times. PNG is also useful for photos with a lot of detail and great contrast. As a result, PNG is often used as the default file format for screenshots since it provides a nearly flawless pixel-for-pixel depiction of the screen rather than compressing groups of pixels together.

PNG also provides transparency, which is a crucial feature. Pixels in PNG files can be transparent in both grayscale and color pictures, allowing users to build graphics that perfectly overlay the information of a website or image.

Uses of PNG

  • PNG may be used for a variety of purposes.
  • Drawings, illustrations, and comics are examples of line art.
  • Handwritten letters or newspaper articles, for example, can be photographed or scanned.
  • Charts, logos, graphs, architectural designs, and blueprints are all examples of graphic design.
  • Page layouts created in Photoshop or InDesign and then saved as pictures are examples of text-based work.

The advantages of the PNG format include:

The following are some of the benefits of the PNG format:

  • Lossless compression preserves picture quality and detail after compression.
  • Supports a wide range of colors — the format may be used to create a variety of digital pictures, including photographs and graphics.
  • Transparency support — allows for the reduction of digital photos with transparent sections.
  • Perfect for picture editing – lossless compressions make it ideal for storing and manipulating digital photographs.
  • Images with text, line art, and graphics benefit from sharp edges and solid colors.

The following are some of the drawbacks of the PNG format:

  • Larger file size — reduces the file size of digital photographs.
  • It doesn’t handle non-RGB color spaces like CMYK, therefore it’s not appropriate for professional-quality print graphics (cyan, magenta, yellow and black).
  • Doesn’t allow you to incorporate the EXIF metadata that most digital cameras utilize.
  • Although it doesn’t enable animation out of the box, there are unofficial addons available.

PNG History

PNG was created by an Internet working group led by Thomas Boutell, who met in 1994 to start developing the format. The GIF format was already well-established at the time. Their objective was to improve color support while also developing an image format that would not require a patent license.

Unisys controlled the GIF format, and its usage in image-processing software required license or other legal issues. Web users could freely create, read, and transmit GIF files, but they couldn’t build software to create them unless they had a deal with Unisys.

On January 4, 1995, the first PNG draft was released, and within a week, most of the important PNG features had been offered and approved. The group generated seven major drafts over the following three weeks.

All of the specifications were in place (draft nine) and accepted by the beginning of March 1995. The initial version of the PNG standard was published as a W3C recommendation in October 1996. When it became an international standard in 2003, new versions were produced in 1998, 1999, and 2003.

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