How to Lower the Amount of Megapixels On a Picture Already Takenby Contributor
It is easy to reduce the size of a digital picture by using Google's free Picasa software, to email the pictures to yourself or to others.
Download and install Picasa. A link is provided in the Resources section. Run Picasa.
Select "Tools" from the drop-down menu at the top and then select "Options."
Select the "Email" tab in the new dialog window that opens.
Select the size you desire using the slider under "Output Options."
Click "Apply," then click "OK."
Now select the photos you want to re-size in your library by highlighting them.
Now click the "Email" button at the bottom of the screen.
Select "Use my Gmail Account," and enter your password when requested to log in.
When the email window opens up, enter your own address to email the photos to yourself, or enter the address of where you would like to send them. Once sent, your pictures will be automatically re-sized to the size you specified in Step 5.