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Chapter 4 Perspective, Scene Design, and Basic Animation
When a computer makes an object larger, it needs to fill in the spaces
between each pixel. This effect is called
dithering.
If it does not fill in that
space, the object would look really funny as it would separate into little dots.
The computer uses interpolation to dither an image when it is resized.
When dithering an image,
the computer chooses a blended
color to fill in between the pixels
that moved. This process repeats
every time the object is enlarged
by more than one pixel spacing.
As more blended pixels are
inserted, the object develops a
blurry look as the color between
the two
native poles
or pixels
continues to distort.
In Figure 4-12, green pixels touch red pixels in certain locations. If this
picture is enlarged, the computer must interpolate a new pixel between these
two native pixels. The figure shows what an interpolated pixel might look
like. The computer adds a pixel and colors it based on information from the
surrounding pixels. The red-green-blue (RGB) color of the red pixel is 222,0,0
(222 density of red, 0 green, and 0 blue). The RGB color of the green pixel is
0,128,0 (0 density of red, 128 green, and 0 blue). The interpolated pixel has an
RGB color of 222,128,0. As you can see, that color is nothing like either of the
original colors. This causes the picture to get fuzzy, distorted, and discolored as
the size increases.
CHEAT CODE: NATIVE POLES
Native poles or native pixels are the
original pixels of an object before it
was modified. The computer creates
an interpolated pixel between two
native pixels when an object is resized.
Figure 4-12.
When an image is resized, the computer must decide what color the new pixels should
be. This can cause an image to become blurry or muddy.
Goodheart-Willcox Publisher; image: Shutterstock.com