Compress is the wrong word. At any time you can make the file size (picture size) anything you want, larger or smaller. If you chose larger the software "invents" pixels that were not there before based on info from surrounding, existing pixels. If you chose smaller, it deletes some pixels while altering the pixels that will remain a bit so that little info is lost. Goals being in both cases to have the result look like the original. I use Irfanview, the most popular free photo software in the world. It is user friendly. On the top tool bar click on image, then on resize/resample. Common sizes are already listed for you to chose from. So is double and half. But you can just type in any number you want. Easy. You need to save your original picture in the size that the camera made. But you can create another copy of any size at any time. Many web sites have a limit on how large a picture can be for them to be able to handle it. For them you'd make a copy and resize it smaller. Gene
