Screen capture and image sequences
Copyright Charley Weiland. Last revision February 15, 2002
This tech tip covers two topics: how to grab a picture of the screen, and how to put a sequence of pictures together to make a slide show or animation.
Screen capture on a Macintosh computer
Hit the Apple-Key (also called command key), the shift key, and the "3" key. This will take whatever is on the screen and write it into a PICT file. Be careful where the cursor is, and what windows are showing.
If you want to just take select part of the screen, instead of the "3" key, use the "4" key. This will turn the cursor into a "+", then you can select a rectangular part of the screen by pressing and dragging the mouse across your region of interest. Once you lift the mouse, that part of the screen is written to a PICT file.
In either case, the file will be written to the same folder that contains your System folder, and the file will be called Picture 1 or Picture 2, etc. You should hear a camera shutter sound when the file is being saved.
Screen capture on Windows
Windows has a print-screen key, which puts the screen image into clipboard memory (like using the copy command). Then you can paste the image into your favorite application (Word, Photoshop, etc.) to save your screen shot. If you press the alt-key with the printscreen you get a copy of the current window.
Animating image sequences or making slide shows from images sequences
If you want to make a slide show from a set of image files, or you want to make an animation from a sequence of images, the easiest way is to use to Quicktime Player (for either windows or Macintosh). You will need to register for the "Pro" version ($29.99). Quicktime is available in the GIS lab, if you don't want to register.
To make the slide show or animation, make sure all the files are in the same folder and that the filenames are all the same except for sequence number, e.g. slide01, slide02, slide03, etc. Then in Quicktime use the File/Open/Image Sequence command. Answer the questions about frames per second and filename, and presto! you have a slide show (or animation). Apple has a more detailed tutorial.