How to specify image size.

There are a few images that are generated on the Outline. They are automatically shrunk to fit outline. When testing page speed, I get a F for image size specification. So how do I satisfy specifying the size without actually changing the size of the picture to match the outline? Controlling the pixel size that members upload cannot be done without limiting them. Perhaps a program that will generate the sizes needed for site automatically. Then again that would be resource intensive to have several size pictures generated.

image size specification.  I am guessing that the outline does not have the width and height specified for the image; and thus you get a message and a degradation in your score.  Personally I would not worry about a score from some test; I would just look at the page load times.

I have page load time down to about 3.5 to  4 secs from 7 secs. I want to get it to under 3 secs if possible and lack of image size shows the highest priority. Next is defer parsing Javascript to the end of page, which would allow page to load  before certain javascript. In any case, just a few more corrections should meet my goal.

if image size needs to be specified in order to get the speed up, then that is in the timeline module which is Wall in the list of modules.  Timeline in the admin, wall for the actually module.