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
67 of 175
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.
3.2.2.1.
Single Point Correction
The simplest image enhancement can be achieved by a linear
modification of the original transfer function. If the image brightness is
weighted towards a particular region (dark or bright), this region needs
to be suppressed, and the less present (the flat) region needs to be
enhanced. The range of the correction is determined by the location of
the break point (X1, Y1) – Figure 3.4. This point (X1, Y1) divides the
camera transfer function into two regions (two lines). The slope of
these lines (the angle between the X axis and the line) determines the
power of the correction. If the angle is less than 45
O
degrees, the
grayscale range will be suppressed. If the angle is more than 45
O
degrees, the grayscale range will be enhanced. The user can set the
optimum (X1, Y1) values.
