Types of Digital Graphics + File Extensions

File extensions are a way of letting the user and their computer know what type of program created/uses any given file.
Computer files have specific characteristics which depend on the software that created them. If you try to open a file using the wrong program, it will fail to open or sometimes even crash the program. The last part of the file name is used to indicate the type of file so the computer can open the correct program simply by double-clicking on the file name, when you want to use the file.
A file extension is very useful. It helps you identify the type of document. So, for example, a file with an extension of .jpg is a photo and a file extension of .exe tells you it’s a program. This is very convenient, but it does mean that your computer may possibly be compromised by malicious files, however unlikely it seems.

Here are the main graphic file formats:

GIF: ‘Graphic interchange Format’ is most commonly used for bitmap images composed of line drawings or blocks of a few distinct colours. The GIF format supports 8 bits of colour information or less. This makes GIF a particularly popular format for web devices, atleast until PNG took over.

JPEG: Like GIF, the ‘Joint Photographic Experts Group’ Format is one of the most popular formats for web graphics. It supports 24 bits of colour information, and is most commonly used for photographs and similar continuous-tone bitmap images. The JPEG file format stores all of the colour information in an RGB image. JPEG was designed so that changes made to the original image during conversion to JPEG would not be visible to the human eye. Most imaging applications let you downgrade the quality for a smaller file size, aswell as the other way round. Unlike GIF, JPEG does not support transparency.

BMP: The ‘Bitmap file’ format is used for bitmap graphics ont he windows platform only. Unlike other file formats the BMP format stores image data from bottom to top and pixels in Blue/Green/Red order. These files are usually large as compression is not supported.

PNG: The ‘Portable Network Graphics’ format is pretty much the successor of the GIF file format.  PNG is pretty much becoming the mainstream format for web images and could replace GIF entirely. It is platform independant and should be used for single images only. Compared with GIF, PNG offers greater colour support and better compression, gamma correction for brightness control across platforms, better support for transparency and a better method for displaying progressive images.

TIFF: ‘Tag Interchange File Format’ is a tag-based format that was developed and maintained by adobe. TIF, which is used for bitmap images, is compatible with a wide range of software applications and can be used across platforms such as Macintosh, Windows and UNIX. TIFF files are generally larger than GIF or JPEG files. TIFF supports lossless LZW (Lempel-Ziv Welch) compression; however, compressed TIFFs take longer to open.