Wayne Adult Community Center
Feature article from the September, 2004 Cyberspace News

 

Picture Acronyms

Acronyms are words formed from the initials or other parts of several words.  They are prevalent in the computer world and can cause a lot of confusion.    You may be aware of the acronyms used for picture files:  JPEG or JPG (pronounced JAYpeg); GIF (pronounced jiff or giff with the hard G sound); BMP (pronounced bitmap); PNG (pronounced ping); and TIFF or TIF.  The acronym you are most likely to encounter is JPEG.

  Most of these acronyms refer to a type of file compression.  Uncompressed picture files are enormous and infrequently used.  One example of this is TIFF files which are uncompressed and, thus, rarely used in computers because of the huge amount of time they take to download and the large amount of memory they use up.  If a good friend sent you a TIFF file, you’d probably go nuts waiting for the blasted thing to load on your system (and might want to reconsider your friendship). 

<>   That’s why we have file formats such as JPEG.  JPEG stands for Joint Photographic Experts Group (named after the group that invented the format).  When a picture file is converted to a JPEG with a .jpg extension, its size is reduced up to 95 percent.  This is done by selective omission  of some pixels (remember that a pixel is a unit of measure denoting a single dot of color).  Although codes are included that allow some of the deleted information to be restored, some definition is lost when the file is opened, thus JPEG is not as sharp an image.  JPEGs do, however, usually work well.  They support up to 16.7 million color shades.   JPEGs are best for photographs, which contain lots of colors and curves.  The drawback to JPEGs is that they can give graphics a somewhat stair-stepped, primitive look.  GIFs (Graphics Interchange Format) don’t have that problem but they only support 256 colors.  For this reason they’re not suitable for photographs.  They are, however, fine for Web graphics where you may not need as perfect an image as you would want on photographs.  PNG (Portable Network Graphics) was developed to circumvent royalty charges for GIF compression.  It has been very slow to catch on.  BMP (bit map) images are used in Windows, are not   sophisticated, are also uncompressed (so they take up a lot of room), and are usually used for graphics rather than for pictures.

Source:  www.komando.com



11/5/04-2125