So as you may know, PictureSnapApp is designed to allow one to import images from any source, and calibrate them to your instrument stage. Then once the image is calibrated, one can navigate to features, add point annotations, FOV annotations and also import what we call "sub images" to the main image using the new image locator feature.
Nick Botto recently complimented us for using ASCII text files for the ACQ calibration files. Basically it's a normal Windows INI format with a different extension. However, we recently revamped the code, so now the coordinates of the annotations and sub images are stored in screen coordinates, not stage coordinates. One can still export the stage coordinates of everything, but internally the code makes more sense to utilize screen coordinates for everything since the stage calibration could be anything (e.g., if one moves the sample to a new instrument), but the annotations always travel in concert with the image. Note that the latest version of PictureSnapApp automatically reformats your ACQ file to utilize the new coordinates system, so all is well from the user perspective.
By the way, just for the record we're using "twip" coordinates for the image coordinate system. Why? Because that's what we started with many years ago in PFE and besides it does provide sub pixel resolution since there are 15 twips per pixel. Of course it gets more complicated because then one has to compensate for the screen DPI when moving from one monitor to another. Normally 1.0, but it can be 1.25 or 1.5 depending on the personalization settings in Windows, but PictureSnapApp handles this automatically.
Now the point here is that of course the point and FOV annotations move automatically to the new instrument, since they are specified in the ACQ file (which has the same name as the image). But when moving your calibrated images to another instrument you'll want to be sure to also move any sub images you have loaded into the calibrated image. Any sub images will always be located in the same folder as the main image and ACQ file so it's easy, but just so you all know.