Archive for February 12th, 2012

February 12, 2012

Bull Ant


Myrmecia, often called bull ants, is a genus of ants found almost exclusively in Australia. These ants are well-known for their aggressive behavior and powerful stings. The venom of these ants has the potential to induce anaphylactic shock in allergic sting victims. As with most severe allergic reactions, if left untreated the reaction may be lethal. Bull ants eat small insects, honeydew (a sweet, sticky liquid found on leaves, deposited from various insects), seeds, fruit, fungi, gums, and nectar. They have larger eyes, and hence better vision, than most ants.

The bull ant famously appears in the philosopher Arthur Schopenhauer’s major work, ‘The World as Will and Representation,’ as a paradigmatic example of strife and constant destruction endemic to the ‘will to live.’ ‘But the bulldog-ant of Australia affords us the most extraordinary example of this kind; for if it is cut in two, a battle begins between the head and the tail. The head seizes the tail in its teeth, and the tail defends itself bravely by stinging the head: the battle may last for half an hour, until they die or are dragged away by other ants. This contest takes place every time the experiment is tried.’

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February 12, 2012

Rolling Shutter

Wagon-wheel effect


Rolling shutter (also known as line scan) is a method of image acquisition in which each frame is recorded not from a snapshot of a single point in time, but rather by scanning across the frame either vertically or horizontally. In other words, not all parts of the image are recorded at exactly the same time, even though the whole frame is displayed at the same time during playback.

This is in contrast with global shutter in which the entire frame is exposed for the same time window. This produces predictable distortions of fast-moving objects or when the sensor captures rapid flashes of light.

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