BOBCAT HD-SDI
Hardware User’s Manual
Imperx, Inc.
Rev. 1.4
6421 Congress Ave.
6/2/2014
Boca Raton, FL 33487
+1 (561) 989-0006
65 of 175
3.2.1.2.
Dual Threshold Binary
If the image has a low contrast and does not have well defined dark and
bright regions, the simple threshold operation does not yield good
results. In such cases a dual (known also as interval or window)
thresholding technique has to be implemented – Formula 3.2. The
binary image output is converted to “white” for all gray level values
between the selected threshold interval X1 and X2, and to “black” for
all gray levels outside (X1, X2) interval. The user can set the optimum
X1 (Low) and X2 (High) threshold values, please note that X2 > X1.
Figure 3.1 shows the original a processed image after a dual threshold
operation.
Output signal =>
“BLACK” if (input signal
≤
X1)
“WHITE” if (X1 < input signal < X2)
“BLACK” if (input signal
≥
X2)
(3.2)
Figure 3.1 – Original and processed image with single threshold.
