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
200 of 329
3.1 OVERVIEW
The camera has built-in several basic image processing functions. More functions will be added
later. Please contact IMPERX for more information.
3.2 IMAGE ENHANCEMENT
In many imaging applications the user will have a dark object on a bright background, many dark
and bright spots or shadows, or the light will not be sufficient, so the resulting image will have a
low contrast, and/or a very low dynamic range. To improve the image quality in such conditions,
BOBCAT offers a set of image enhancing features – thresholding and multi-point image
correction. The processing function is applied to the entire image unless AOI8 is enabled as
“Processing ROI”. In this case the processing function will apply only to the selected ROI.
3.2.1 Threshold Operation
In many applications the binary images are much simpler to analyze that the original gray
scale one. The process, which converts the regular gray scale image to binary, is called
“Thresholding”. Thresholding is a special case of intensity quantization (binarisation)
where the image can be segmented into foreground and background regions, having only
two gray scale levels “white” and “black”. Selecting the threshold value is very critical for
the binary image quality, and it is to a great extend scene dependent. If a threshold level is
chosen correctly, this will produce a well-defined boundary of the object, which is
essential. In some cases it is desirable if part of the image is binary and some is grayscale
image. The camera has built in four thresholding modes:
3.2.1.1
Single Threshold Binary
If the image is a high contrast scene and has well defined bright and dark regions a
simple binarisation technique can be used for thresholding – Formula 3.1. The
binary image output is converted to “white” for all gray level values higher or
equal to the selected threshold point X1, and to “black” for all gray levels lower
than X1. The user can set the optimal threshold value. Figure 3.1 shows the
original and the processed image with single threshold.
Output signal =>
“WHITE” if (input signal
≥
X1)
“BLACK” if (input signal < X1)
(3.1)
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
