The PNG file, or Portable Networks Graphics as it is the acronym for, is a lossless form of data compression for a bitmapped graphic or image. At the time of its creation, there was a big issue over the use of the gif and its lossy compression format with regards to licensing as the compression method used was patented. However, the PNG file never really took hold like it was expected to and although the file is often smaller, cleaner and of course patent-free. Today though, while the patent used on the compression of the gif is no longer valid, now the PNG format is growing in popularity.
The PNG comes in a number of different formats, however the most common are those of the 24-bit RGB. This particular image format was specifically developed for use on the internet which is why it does not support the CMYK colour palettes. The PNG can be formatted as an 8-bit image as well which is very similar to that of the gif in that it supports 256 colours and index transparency. However, to go beyond that, the 8-bit version of the PNG can also support Alpha transparency yet very few developers realised that the Internet Explorer did recognise this format when they were having to add JavaScript hacks to the website.
It was back in 1995, only 3 years after the inception of the World Wide Web Consortium or W3C that the PNG was first developed. At this particular time period, the gif image was making use of a compression format known as Lempel-Ziv-Welch or LZW which was a patented process owned by the Unisys Corporation. However, this patent has long since expired and while the gif had served its day, without regards to the fact that it is also a lossy image format, many developers still make use of it simply because Microsoft Windows has continuously refused to add the proper rendering for the PNG file format.
While there has been another file format known as APNG which was intended to be the animated version of the PNG in competition to the animation capabilities of the gif file, this particular format has not been standardised as of yet. It is still possible to make animated PNG files by using its standardised companion, the MNG or Multi-Image Network Graphics file format.
It was Oliver Fromme who had already become well known in the computer graphics world for his development of the MS-DOS JPEG viewing program known as QPEG who came up with the name for the file format. While on a usenet about graphic development, he posted a message in which he insisted Ping is Not Gif and thus the PNG became the extension for the graphical format.
Original Authors: Nick
Edit Update Authors: M.A.Harris
Updated On: 06/03/2009
