Moving images from one instrument to another

[John Donovan]

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.

[John Donovan]

Gareth Seward helped me to locate and squash a number of bugs when using the Transform | Rotate Image/Stage Orientation dialog. So if you plan on utilizing this feature (because your sample was oriented differently when mounting the sample in a another instrument), you'll really want to update your PictureSnapApp using the Help | Update PictureSnapApp menu.

For example, here is an image scanned horizontally and some images acquired:



and now rotated using the Transform menu:



It's good to see this work on an actual sample!   Thank-you Gareth.

[Gseward]

Here are a few screen shots from my testing of PSA; they highlight a few of the features that are easy to use and useful. My goal in using PSA was to document the location of features of interest (FOI) with instrument A (in this case an SEM), e.g. with images at different magnifications, and coordinate information, such that I could relocate the FOIs on instrument B. Ideally I would be able to use the base-map and coordinate information of a FOI to relocate the feature, and the higher mag images to allow positive identification of the exact area I would like to investigate using a different instrument/technique. The idea is that the coordinates for FOI in instrument can be transformed to the coordinate system of instrument B, and the images acquired in instrument A be transformed to the appropriate location and orientation.



This is PSA running on my SEM instrument. This is a full version of PSA with control of the instrument through FEIs DCOM interface. Here I have imported and calibrated the base map (a XPL scan of a geological thin-section from my flatbed scanner). I have defined 3 field of view (FOV) annotations (white rectangles), the coordinates and dimensions of which are displayed in the FOV Annotations Window. Within one of the FOV areas I have defined 5 point annotations representing FOIs. The coordinates of these points are displayed in the Point Annotations Window. Also visible is the 'Full View' window that shows the full image of the basemap for easy 'double-click' navigation. At this point I have acquired and imported a number of SEM images, one of which is visible in the Image Locator window. The location of this SEM is also shown overlain on the base map and annotated with pink text. The Image Locator window also allows digital 'zoom' to assist in identifying features.



Here I have checked the 'Display All Image FOV locations' button and the 'Display Image FOV outline only' check boxes so that I can see where my SEM images are located, but still see the basemap.



and here with the SEM images displayed. Now I am ready to move my work onto a different instrument. Instrument B uses a 'text only' version of PSA since there is no driver for the stage. It also happens to have a rotated stage coordinate system. I use the Transform | Rotate Image/Stage Orientation option, and recalibrated the basemap for instrument B.



Here is the rotated basemap and SEM images with all coordinates transformed into the coordinate system for instrument B.