Reduce Image Size (File Size) with Attachment Control
Setting on Attachment Control and/or Control Action "Transform" which would reduce size of image to target Height (by pixel), or Width, (Both would reshape image. "Transform Image" action. Option to make thumbnail, or enum of 4 common sizes.
File Attachment would have Transform File, (type/ext aware) to Max compress, Medium Compress.
Jeffry Belnap commented
Output of control action could target other control, or overwrite same control. (This works in iso storage where server temp holds the "uploaded file" ....