Here is a small macro produced from your screenshot with some comments.
First you have to set the scale in your image to measure it in µm, see:
You can use the macro recorder to integrate more commands in the script, see:
ImageJ Macro API:
If all of your images have an equal size you can automatize that and center two Oval selections on your image by calculating the pixel dimensions from the scale because the Ovals are set in image pixels:
//Please detect your own scale!!!!!!!!!
makeLine(10, 563, 22, 564);
run("Set Scale...", "known=200 unit=µm");
//Set the measurements
run("Set Measurements...", "area mean centroid integrated median redirect=None decimal=3");
//Get the scale values to calculate the size for the Oval ROI's!
getPixelSize(unit, pw, ph, pd);
//Calculate the ROI dimensions in pixel (0.3 and 0.1 cm)
//Set the selections and measure them with the before adjusted measurements!
makeOval((getWidth()/2)-(ovalSizeBig/2), (getHeight()/2)-(ovalSizeBig/2), ovalSizeBig, ovalSizeBig);
makeOval((getWidth()/2)-(ovalSizeSmall/2), (getHeight()/2)-(ovalSizeSmall/2), ovalSizeSmall, ovalSizeSmall);
Apply your modified macro to a folder of images with the Batch converter:
If the Oval selections should not be centered in the image (if the retina is not centered) some other techniques have to be applied to extract the center of measurements.
You can also leave out the first two commands of the macro and set the scale before any macro is executed with the option “Global” applied, see again: