Chapter 10
MDP-621/641/640
MENU operation
Operation manual
(3) Mix
Small fish schools that return weak echoes such as white bait, etc are detected mainly by the
high frequency ultrasonic returns. Detection of these types of small fish schools by the low
frequency returns is difficult. The image processing uses this feature to identify these small fish
schools from larger schools. There are 3 different types of image combination processing.
(a) A Mode
This mode mainly uses the high frequency image. When there is no low frequency image from
the same depth as the high frequency image, the high frequency image is displayed as it is.
When the low frequency image from the same depth is present, both images are combined
and displayed in gray.
(b) B Mode
When mixed colors are contained within the combined image, fish larger than white bait are
mixed in with the school. The difference of the high frequency image level and the low
frequency image level is displayed as a composite image.
The difference between the high frequency and the low frequency detection signals is
measured and the color resulting from the differentiation between the two signals is displayed.
Strong signal colors are displayed for high level differences in the detected color.
(c) C Mode
This mode mainly uses the high frequency image and is useful in displaying small size fish.
When there is no low frequency image from the same depth as the high frequency image, the
high frequency image is displayed as it is. When the low frequency image from the same
depth is present, the images are processed so the low frequency component is suppressed
and the high frequency image is displayed.
Setting range:
A, B, C
0 A
1 B
C
2
Mix
(4) Smoothing
This function reduces the screen image flicker resulting from the video transmission rate.
Setting range:
OFF, ON
0 OFF
1 ON
Smoothing
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