Rectangle png series#
A PNG file consists of a PNG signature followed by a series of //chunks//. For example, Microsoft Windows viewer has the capability to open PNG files as the OS has by default the support available as part of installation. Grayscale images of up to 16 bits per pixelįull alpha channel (general transparency masks)Īlmost all Operating Systems have support for opening PNG files. Truecolor images of up to 48 bits per pixel The following table lists the GIF features that are inherited by PNG file format in addition to new features. PNG file format was designed to be simple and portable, legally unencumbered, interchangeable, flexible and robust. This version of PNG differs only slightly from version 1.2 and adds no new chunks. November 2003: PNG became an International Standard (ISO/IEC 15948:2003).August 1999: Version 1.2, adding one extra chunk, was released.December 1998: Version 1.1, with some small changes and the addition of three new chunks, was released.The same became a W3C Recommendation in October 1996. October 1996: PNG specifications Version 1.0 were released and later appeared as RFC 2083.
Key events with respect to PNG file formats are listed below: The first proposal and name for PNG file format came in January 1995. This along with other GIF limitations created a need for replacement of GIF file format. The main reason behind the creation of PNG file format was the patented compression algorithm, Lempel-Ziv-Welch, used in the GIF file format. With the passage of time, PNG has evolved as one of the widely used image file formats. PNG file format supports lossless image compression that makes it popular among its users. However, PNG file format does not support animations. This file format was created as a replacement of Graphics Interchange Format ( GIF) and has no copyright limitations. A PNG (Portable Network Graphics) file is a raster image file format that uses lossless compression.