CAMERAS FRAME GRABBERS IMAGING SOLUTIONS
BOBCAT Hardware User’s Manual
IMPERX
Rev. 2.0.7
6421 Congress Ave.
4/8/2014
Boca Raton, FL 33487
www.imperx.com
+1 (561) 989-0006
202 of 329
3.3. The image output is a gray scale image for all gray level values between the
selected threshold interval X1 and X2, “black” for all gray levels lower than X1,
and “white” for any gray levels higher than X2. The user can set the optimum X1
(Low) and X2 (High) threshold values, please note that X2 > X1. The image gray
scale range is only from values X1 to X2.
Output signal =>
“BLACK” if (input signal
≤
X1)
“Gray Scale” if (X1 < input signal < X2)
“WHITE” if (input signal
≥
X2)
(3.3)
3.2.1.4 Dual Threshold with Gray Scale Stretch
In some low contrast applications, the threshold operation along with a gray scale
stretch might yield a good result – Figure 3.3. This is similar to dual threshold with
a gray scale, but the image gray scale is digitally stretched to full 12 bit gray scale
– Formula 3.4. The user can set the optimum X1 (Low) and X2 (High) threshold
values, note that X2 > X1.
Output signal => “BLACK”
if (input signal
≤
X1)
“Full Gray Scale” if (X1 < input signal < X2)
“WHITE”
if (input signal
≥
X2)
(3.4)
Figure 3.3 – Original and processed image with threshold and gray scale stretch.
3.2.2 Multi Point Correction
Multi point correction is a modification of the slope of the camera transfer function (TF),
which results in the suppression or enhancement of certain image regions. The original
camera transfer function is linear and maps the data 1:1. The new (corrected) transfer
function has one or two sets of variable (X, Y) and based on the relation between the
variables a correction of certain image regions can be achieved. The camera has two built
in correction modes.