PC Doctor January 16, 2015

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Dear PC Doctor:
 
Someone asked me to send them a picture but they said they needed it as a gif file, not a jpeg.  I didn’t know there were different kinds of picture files.  Does it matter?
 
      Thanks, George
 
Dear George:
 
There are 3 kinds of picture formats: gif, jpg, and PNG.  All three are picture files, and all 3 can be attached to an e-mail. (There are more kinds of file types, but these are the ones we see most often.)
 
Jpgs are what most people are used to using for photographs.  Jpgs can use millions of colors and can be very crisp and clean.  They are easily sent between users, but do lose some quality.
 
Gifs are usually used for simpler images, such as logos and icons.  Gifs are also used for animations.  Gifs use only 256 colors; the gif format forces the image to use whichever of the 256 colors is closest to the original.  In complex images, the result can be blotchy or patchy.  One of the reasons your friend might have asked for a gif is that gif files support transparency.  This means that you can specify one of the colors in your image to be transparent, so the background behind the gif shows through.
 
PNG files can sometimes be very big, but they have an advantage in that they do not lose quality when they are edited.  They tend to be larger files, which makes sharing a little more difficult.
 
Until next time… Happy Computing!
 
     PC Doctor

Posted: to Athol Library News on Fri, Jan 16, 2015
Updated: Fri, Jan 16, 2015

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