jpeg images

  moh23 22:23 08 Jan 2004

what is the diff between a jpeg image and a bmp image and can you change one format into the other,iam doing a family tree and to put pics onto the tree they have to be bmp but all my photos are jpeg

  VoG II 22:37 08 Jan 2004

A bmp is a bitmap and a jpeg is a compressed image. You could open your jpegs in IrfanView click here then File/Save As and select bmp.

  Pesala 23:17 08 Jan 2004
  GroupFC 08:20 09 Jan 2004

A very useful summary - Thanks!

  Clint2 10:55 09 Jan 2004

Thank you, the clearest explanation I have read, on the subject.

  Pesala 11:19 09 Jan 2004

JPG compression is efficient for photos, but for screenshots always use PNG. Compare quality with file size for different JPG quality levels

click here 51K @ 75 quality

click here 31K @ 50 quality

click here 21K @ 30 quality

click here 20 quality

click here 9K @ 10 quality

With a photograph, the image degradation doesn't really begin to be obvious until you get down to 20 or less, but with a screen shot it is very obvious at 50 or higher.

  Pesala 11:33 09 Jan 2004

Here's two images of similar file sizes

PNG 78K click here

JPG 77K click here

The JPG was compressed in Irfan View from the same screenshot, using a quality setting of 35 to get a similar file size. At a setting of 50, the quality is acceptable, though still not as good as the PNG, and the file size is 99K as opposed to 78K.

All this goes to prove that it is worth learning about graphic file formats to make your images look as good as possible, even (or especially) when you need to send them by email or post them on the web.

  moh23 19:37 09 Jan 2004

thanks for the help works just fine

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