Chapter 2
Hardware Overview
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National Instruments Corporation
2-3
To separate objects under consideration from the background, select a pixel
value range. This pixel value range is known as the gray-level interval, or
the threshold interval. Binarization works by setting all image pixels that
fall within the threshold interval to the image white value and setting all
other image pixels to 0. Pixels inside the threshold interval are considered
part of the particle region. Pixels outside the threshold interval are
considered part of the background region.
Inverse binarization flips the assigned bit numbers of the particle region and
the background region. Thus, all pixels that belong in the threshold interval,
or the particle region, are set to 0, and all pixels outside the threshold
interval, or the background region, are set to the image white value.
The following figure illustrates binarization and inverse binarization.
Figure 2-2.
Binarization and Inverse Binarization
Multiple-Tap Data Formatter
Many digital cameras transfer multiple taps, or pixels, of data
simultaneously to increase the frame rate of the camera. However, the data
in each tap may not be transferred in the traditional top-left to bottom-right
direction. Also, the taps may not transfer data in the same direction.
The multiple-tap data formatting circuitry on the NI 1430 can reorder the
data from multiple taps. The data from each tap can be independently
scanned either from left-to-right or right-to-left and top-to-bottom or
bottom-to-top. The bit depth and tap ordering of the data do not need to be
the same between the two ports of the NI 1430.
NORMAL
Stored V
alue
Sampled Data
INVERSE
Stored V
alue
Sampled Data
