Portable Network Graphics Format Explained

What is a PNG file?

The PNG file format is one of the newest ways to store and transmit digital images. PNG stands for portable network graphics and has been developed to replace the GIF file format which can reproduce images in only 256 colors. GIF files are widely used on the web for logos and line drawings but the technology is patented and the PNG format is viewed as a way around that.

PNG files can produce color from a 24 bit palette and like GIF files are called lossless meaning that the quality of the image is not sacrificed. You can edit them and resave them and they will still look as good as the original. PNG files also can be blown up without losing the quality of the image as you might with a JPEG file.

JPEG files may still be preferred over PNG files for photographic images because of the size. JPEG files are significantly smaller than PNG’s but the quality will not be as good. JPEG’s are a lossy coding system which sacrifices some detail to achieve greater compression of the file size for easier storage and quicker transfer. If you are posting photos on the web or emailing them to someone, a JPEG file will work best.

Where the PNG file format is superior is when the image is going to be reproduced in print or in cases where it must go through extensive editing to be posted on a web site. The JPEG files will suffer from a loss of quality the more it is edited and saved but the PNG files will not. PNG is also the better choice for images that contain text and lines.

Eventually, it is widely believed that PNG files will take the place of GIF files and become the industry standard however, for now the format is only recognized by advanced versions of browsers and desktop publishing software. Adobe Photoshop will recognize PNG files and so will Corel Paint Shop. Internet browsers, Netscape and Explorer will support the PNG file format if you using Version 4.0 or higher.