Step 1: What the Blink?
PC running Windows XP, which includes Windows Picture and Fax Viewer. PAINT program to capture, trim and save pairs of images on the computer. The blink effect can probably be implemented using many other programs and on MACs.
To download a free image editor and viewer that will blink two images, see IRFANVIEW in Comments section below this Instructable for details.
Step 2: Grab a Nice Pair
The Past Editions pulldown menu allows you to choose more pairs, sorted by publication date. Try the puzzle published Sept07, 08, Brass-Section, for a start. Building-Boom May 25, 08 is rated extreme; also see Dec 23, 07; Aug 19, 07; Sept 02, 07.
This photo puzzle demonstrates the blink principle, but you can use your PC to compare any two items or images, of whatever size, that you can get into your computer by any method. You can quickly find flaws in complex machine parts and stuffed printed circuit boards and detect what might have changed between different frames taken by earthbound surveillance cameras or by satellites.
Step 3: Image Capture, Step-by-step
To capture the two individual images for blinking, at the Post web site Puzzle for Sept 07, 08, Brass-Section, click Enlarge if available. Right-click anywhere on the photos > copy; Click (-) to minimize Washington Post Magazine window. Click Start> Paint; Click on the white space and use mouse to expand the white space if necessary; Edit>paste. Click the Select tool and carefully outline image #1; Edit>copy; Click (-) to minimize window of Untitled Paint. Start> Paint again to open a new window; expand white space if needed; Edit>paste. Click on the white space and use mouse to shrink white space to match image edges; File>save-as produces dialog box (Save-in: Desktop; type in filename, such as 1brass-section; Save as file type: jpg); Click Save; Click (X) to close window. Maximize Untitled Paint window, repeat steps to capture 2brass-section image and place on desktop; Click (X) to close window. Maximize Untitled Paint window; Click (X) to close that window.
You can use similar steps to capture a copy of the images connected as a pair if you like. The web site allows you to enlarge recent puzzles, but you may not want to enlarge when you capture an attached pair because the result could be too big to fit in your computer screen.
Step 4: Winkin' and Blinkin' Step-by-step
Windows Picture and Fax Viewer is peculiar to Windows XP. Software included with most digital scanners and cameras can create a slide show that will toggle between two images, as can photo editing programs. To download a free image editor and viewer that will blink two images, see IRFANVIEW in Comments section below this Instructable for details.