Friday, 3 October 2014

Gestalt - Gestalt and Video - A Useful Tip

If I have some video of a bird requiring identification but the footage is shaky there are a couple of things I do to improve quality.  

Firstly I find the most convenient and readily available package for viewing footage to be Quicktime.  Simply by using the arrow keys video can be moved forward and backwards frame by frame.

But if the video is very shaky and I want to get an appreciation of gestalt (HERE) I will sometimes take a number of consecutive frames and create an Animated Gif from them.  To restore the appearance of a steady image I overlay the frames with the bird's eye in the same position on the screen in each.  Run the video and, like magic, the video appears shake-free.  The final image will have to be cropped to accommodate the different positions of the frame edge.  There is a loss of colour and definition but that isn't the point of animated gif.  We are only interested in gestalt.

Below I have added a number of animated gifs made from video footage I took between Madeira and the Salvagen Islands in 2006.  As one might imagine, given that I was on a small sail boat in the Atlantic the original footage was far from steady.

Fea's Petrel Pterodroma feae off Madeira and Salvagen Islands.  Upper image is of a bird gaining momentum having just left the surface of the water.  Steadying the footage allowed an appreciation of the subtle movement of the bird's wing as it enters and sustains it's classic arching flight.

I love animated gif but unfortunately the package which I use to create these files (Adobe ImageReady) is not supported by Windows 7.0 so I have to use an older computer with XP to create these files.  There are some free animated gif generators online but I havn't tried any and I don't know if they are as accommodating and dynamic as ImageReady,

Bulwer's Petrels Bulweria bulweria off Salvagen Islands.  Steady footage allows us to appreciate the distinctive paddle-shaped tail as Bulwer's takes off from the water, a feature not seen in steady flight.

White-faced Storm-petrel Pelagodroma marina off the Salvagen Islands, where there is a large breeding colony.  Steadying the image below helped capture and display this bird's crazy feeding antics.  Unfortunately the camcorder used for this footage (Sony DCRTRV-110E) had a habit of focus tracking a little too much so focus drops every few frames.  Still I think you can see the huge potential of this medium.

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