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[N]
Normalization correlation
To determine whether the levels between the reference image and the input image match, the IV-
C35M uses an information processing method called "normalization correlation." This is a method
used to calculate relationship between two groups of data.
- Factors determining the correlation value If the densities of the two images have the same
tendency (positive correlation), the two images are said to resemble each other. If the densities of
the two images have opposite tendencies (negative correlation), the two images are said not to
resemble each other. Therefore, areas of the reference image and the input image which
resemble each other (the areas of both images are brighter, or darker) are positive, and areas
which do not (the areas of one is brighter and the other is darker) are negative.
- Correlation formula = { A ‚ B x C } x 10000
A = N (I x T) — ( I) x ( T): Correlation between input image and reference image
B = N (I x I) — ( I) x ( I): Correlation between input images
C = N (T x T) — ( T) x ( T): Correlation between reference images
(N: Area of reference image, T: Density of reference image, I: Density of input image)
[O]
Object identification and numbering function (labeling)
Object identification and numbering (labeling) is a process for locating separate object and assign-
ing serial numbers (labels) one at a time in a binary image. By this process, multiple objects in the
same binary image can be handled separately or as a group.
Binary
conver-
sion
4
[P]
Partial CCD reading
The "partial CCD reading" technique reads only that part of the CCD which contains the object
needed for image processing. This can shorten the data transfer time from the CCD camera to the
image memory.
To read the entire CCD image (480 horizontal lines) takes approximately 33 ms. With the partial
reading technique (e. g.: 120 horizontal lines) can take only 25 % of the time to read the entire
image.
The IV-C35M can automatically determine the width of the partial image window. You can change
back and forth between reading the whole image and a partial image.
Whole image reading Partial image reading
512
Object
identifi-
cation
(in order of
scanning)
3
Object identification
(in order of area)
3
2
Island
1
512
1
2
Island
4
G-9
Glossary
G
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