All you want to do, is email a simple photo to one of your friends or colleagues, but the various formats you can resize images to and which ones you should be using, are just too confusing. Let’s start from the beginning – The most well known format for graphics is .jpg. JPEG is the abbreviation for “Joint Photographic Experts Group”. JPG’s are popular and frequently used due to their excellent compression abilities which ensure that a file is as small as possible, but the images don’t lose too much of their quality. You can always use jpg’s if you need to forward graphic files without having to worry about the files’s size. BMP or the Bitmap format is one of the oldest and most primitive graphical types and has NO compression. In computer graphics, a bitmap or pixmap is a type of memory organization or image file format used to store digital images. The term bitmap comes from the computer programming terminology, meaning just a map of bits, a spatially mapped array of bits. Bitmaps are generally large and unnecessarily take up a lot of pace which clogs the network and email servers. It will also fill up your mailbox very fast if you keep copies of your emails in your Sent items , as well as the receiver’s mailbox. Try to avoid bitmaps as far as possible. GIF (Graphics Interchange Format) is a bitmap image format that was introduced by CompuServe in 1987 and has since come into widespread usage on the World Wide Web due to its wide support and portability. The format supports up to 8 bits per pixel thus allowing a single image to reference a palette of up to 256 distinct colors. GIFs are suitable for sharp-edged line art (such as logos) with a limited number of colors and for small small animations and low-resolution film clips. In view of the general limitation on the GIF image palette to 256 colors, it is not usually used as a format for digital photography. Digital photographers use image file formats capable of reproducing a greater range of colors, such as TIFF, RAW or JPEG. To prevent graphic files clogging up your mailbox and those of friends and colleagues, resize your photos or images before you email them. You don’t need to send a high resolution photo to someone for them to see what’s on it – unless the receiver is supposed to make a high quality print. PNG (Portable Network Graphics) is a format designed for transferring images on the Internet, not for professional-quality print graphics, and therefore does not support non-RGB color spaces such as CMYK. PNG offers a variety of transparency options. TIFF‘s (Tagged Image File Format) are used by professional printers for the best possible quality prints with some compression. Originally created by the companyAldus for use with what was then called “desktop publishing”, the TIFF format is widely supported by image-manipulation applications, by publishing and page layout applications, by scanning, faxing, word processing, optical character recognition and other applications.
(Information supplied by Neels Blom & Wikipedia)