How Digital Photography Works

(^126) PART 2 HOW DIGITAL CAMERAS CAPTURE IMAGES
Electronic Image Stabilization
Electronic image stabilizationis the one method to cor-
rect movement blur that does not use a mechanical appara-
tus, such as gyroscopes, and which does not attempt to
correct vibration before displaced light reaches the image
sensor. While a camera’s shutter is open, every thousandth of
a second the microchip embedded in the camera uses elec-
tronic image stabilization to examine the patterns of light cap-
tured in the form of electrical charges by the imaging sensor.
But if the images do not match, the processor looks for a pattern
that does match the previous impression. Then the processor shifts
the new electronic charges coming from the pixels so that they line
up with the charges that preceded them.
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The processor compares that image with
the first one that was sent from the image
sensor a thousandth of a second earlier. If
the colors of all the pixels match, the
processor puts the new image into storage
along with its predecessors, and their com-
bined electrical charges are added
together to contribute further to the final
digital photograph or frame of video.
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Because this method involves the processor manipulating
the raw data on-the-fly, there is some image degradation.
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