Reasons for downsampling an image
You may wish to downsample an image for a number of reasons:
- To increase the processing speed when editing or printing PDF documents
containing pixel images.
- To adjust the resolution of images (dpi) to their final output screen
ruling, expressed in lines per inch (lpi).
- To publish your PDF documents on the Internet.
A good rule of thumb to specify the optimal resolution is the following:
screen ruling (for example 150 lpi) x 2 = image resolution (300 dpi)