I love all the drawing capabilities that Access has for reports! and put together an extensive reference page here:
VBA syntax and explanations for drawing Microsoft Access Reports. Big reference.
msaccessgurus.com
At the top, you can quick jump to general information, Methods, Properties, and a few Functions -- as well as pages with VBA Examples you can try yourself.
Here is my Help for Circle, which has notes so I can use it better myself and also includes a link to the Microsoft help for Circle.
VBA syntax and explanations for drawing Microsoft Access Reports. Big reference.
msaccessgurus.com
Duane
@DHookom has some great examples too.
To draw a circle on top, as a minimum, you'll need a center coordinate and a radius. You can use the boundaries of your image control to figure those out ... but how to tell if the image is too wide? and what would be the position? Do you have a way to logically determine that?
Before the circle is drawn, you can set (for the Report object) DrawWidth, ForeColor (which I forgot to mention here! since you can optionally set Color to override that), DrawStyle, FillStyle (0 for Transparent), etc
Note that the Circle method can be used to draw circles with different (or no) fill color and outline, as well as arcs that are filled or not, and ellipses