Insert Picture Field, controlling quality/resolution

Hi, i'm preparing a form for my company which includes several pictures. When the pictures are added the file size gets very big (20-30MB). Is there a way to downscale (ppi/resolution) the picture while it's being imported in an image field (through the event.target.buttonImportIcon(); maybe some parameters in the function call?)? I know i can scale the dimensions (WxH) in the properties to fit the field but I wasn't able to find a way to scale the quality/resolution. The only way i found is to "Save as other..." -> Optimized PDF -> and change the image ppi there, but i cannot have my users go through all those steps every time they need to send me the files.