Wednesday, 7 April 2010

Different file formats

JPEG and GIF formats
In computing, JPEG is a commonly used technique of compression for photographic images. The name JPEG stands for Joint Photographic Experts Group, the name of the committee that created the standard. JPEG is mostly used for storing and transmitting photographs on the Web.

For this application, JPEG is considered far superior to GIF (Graphics Interchange Format), which uses a palette with a maximum limit of 256 distinct colors for each frame. The color limitation makes the GIF format unsuitable for reproducing color photographs and other images with continuous color, but it is well suited for more simple images.

JPEG is also preferred to PNG(Portable Network Graphics), which produces much larger image files for this type of image due to its loss less compression. PNG was created to improve upon and replace the GIF format. The JPEG compression algorithm is not well suited for line drawings and other textual or iconic graphics, and thus the PNG and GIF formats are preferred for these types of images.

A recent trend has been observed wherein it was discovered that PNG format is the most widely used although it much loading time. Certain advantages of PNG over GIF formats are mentioned below

  • PNG achieves a much smaller file size than GIF format
  • It offers true color up to 48 bits, whereas GIF uses 256-color palettes
However, extensive use of PNG format has nonetheless not reduced the popularity of both GIF and JEPG formats. Although gradients were used to a minimum in Web 1.0 it became an important aspect of Web 2.0 Design. In the past few years, there is an increasing demand of using gradients, which involves a smooth transition between two or more colors. If the gradient is a simple two-color fade, GIF format is a good choice whereas in complex gradient transitions, JEPG is a better bet.

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