MV Gauge DirectShow Filter
The MontiVision Gauge filter allows the measure with
subpixel accuracy within the video image. The filter supports
some basic calculation functions with the IMVGaugeCalculations interface.
Additional the filter provides some I/O output pins that could
devliver calculation results, adjusted with the IMVAutoCalcSetup interface.
This filter allows together with the MV I/O Renderer filter and
I/O Controls a fast creation an measurement application. Look
at the MV Gauge sample application for a customisable
This MontiVision DirectShow Filter is used in combination with
the MontiVision Smart
Control in the Gauge Sample
Supported COM Events
The filter supports following events through the IMVFilterEvents interface.
Look at the filter events
page for more information.
|A filter starts processing a video frame or sample.
|A filter finishes processing a video frame or sample.
Supported I/O Pins
||Outputs the result of
the corresponding calculation.
MV Gauge Property
Uses the IMVGauge and the IMVAutoCalcSetup interface
to setup the filter.
The Areas of Interest (AOI) property page contains controls to
initisalise the edge detection. Therefore hte user has to
define some line start and end points. On this lines the MV gauge
filter calculates the best gradient with subpixel
|Areas Of Interest
||Desribes a line for the edges detection. Read the Attention
block from the filter property page. The index is used to identify
|Units per Pixel
||Factor for calibration of the output values. The factor
contains the count of unit values for one image pixel. E.g.
2.56 if one pixel is 2,56 mm in the real world. Is this case the
output values from the filter are in mm units.
|Draw AOI Lines
||Draw the lines for the Area Of Interest with the selected
||Draw a cross on detected edges with the selected color.
The Auto Calc Setup page initialise the output calculation for
the output I/O pins [0...7].
Select the index of an output in within the list control. With
the calculation combo box select the calculation algorithm.
The last step is to select the points for the calculation. The
points are the indexes of the AOIs from the Area Of
Interest property page.
With the checkbox from the index column the calculation could be
enabled or disabled. The last feature from this page, the Draw
Results checkbox , allows to draw the results into the
output image with the selected color.