Specifications

Intel
®
Image Processing Library Reference Manual
9-4
9
IPL_DITHER_BAYER The Bayer threshold
dithering algorithm.
levels The number of output levels for halftoning
(dithering); can be varied in the range
[2..(1<<
depth )],
where
depth is the bit depth of the destination
image.
Discussion
The function iplReduceBits() reduces the number of intensity levels
in each channel of the source image srcImage and places the results in
respective channels of the destination image
dstImage .
The
levels parameter sets the resultant number of intensity levels in each
channel of the destination image.
If the
noise value is greater than 0, some random noise is added to the
threshold level used in computations; see [Schumacher]. The amplitude of
the noise signal is specified by the
noise parameter set as a percentage of
the destination image luminance range. For the 4x4 ordered dithering mode
(see [Bayer]) the threshold value is determined by the dither matrix used,
whereas for the error diffusion dithering mode the input threshold is set as
half of the
range value, where
range = ((1<<depth) - 1)/(levels –1)
and depth is the bit depth of the source image.