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When the
portion of the source image
to be viewed is larger than
the viewing window, the
image is Downsampled
to reduce the number of
pixels. Downsampling
displays less pixels than
are available, and can be a
nearly lossless zoom.
As you zoom
in you reach a point where
the size of the portion of
the source being viewed and
viewing window is the same.
Image quality peaks here, at
the native resolution. This
is the
Pixel Floor, and
zooming in past this point
changes the process and
introduces quality
degradation.
Upsample
is used when the source is
smaller, the computer fills
in between the existing
visual data (which is called
interpolation), and
quality degrades after one
or two steps. The quality of
the interpolation software
directly affects the image
quality when zooming using
the upsample process.
Click here
for a look at how digital
zoom factors are calculated. |
