protected void ProcessFrame(SpeedometerFrame frame)
{
SpeedMeasurement result = speedMeasurer.Measure(frame);
decimal PixelsPerHour = result == null ? 0 : result.SpeedPPH;
decimal MetersPerHour = settings.PixelsPerMeter <= 0 ? 0 : PixelsPerHour / settings.PixelsPerMeter;
SpeedKph = MetersPerHour / 1000;
SpeedUpdated(this, SpeedKph);
if (lastReportedSpeedKPH == null || SpeedKph != lastReportedSpeedKPH)
{
lastReportedSpeedKPH = SpeedKph;
SpeedChanged(this, SpeedKph);
}
}
/// <summary>
/// Returns the speed of the largest moving object between this frame and the last. May return null.
/// </summary>
/// <param name="frame"></param>
/// <returns></returns>
public SpeedMeasurement Measure(SpeedometerFrame frame)
{
float motion;
BitmapData data = frame.Frame.LockBits(ImageLockMode.ReadWrite);
try
{
using (UnmanagedImage unmanagedImage = new UnmanagedImage(data))
motion = detector.ProcessFrame(unmanagedImage);
}
finally
{
frame.Frame.UnlockBits(data);
}
Rectangle? largest = GetLargestRectangle(blobCounter.ObjectRectangles);
SpeedMeasurement result = null;
if (largest != null && lastLargest != null)
{
decimal distLeftPx = largest.Value.Left - lastLargest.Value.Left;
decimal distRightPx = largest.Value.Right - lastLargest.Value.Right;
decimal absDistLeftPx = Math.Abs(distLeftPx);
decimal absDistRightPx = Math.Abs(distRightPx);
decimal greater = absDistLeftPx > absDistRightPx ? distLeftPx : distRightPx;
if (greater != 0)
{
result = new SpeedMeasurement(greater > 0 ? MovementDirection.Left : MovementDirection.Right, Math.Abs(greater), frame.Timestamp - lastFrameTime.Value);
}
else
{
decimal dx = largest.Value.Center().X - lastLargest.Value.Center().X;
if (dx > 0)
{
result = new SpeedMeasurement(MovementDirection.Right, dx, frame.Timestamp - lastFrameTime.Value);
}
else if (dx < 0)
{
result = new SpeedMeasurement(MovementDirection.Left, -dx, frame.Timestamp - lastFrameTime.Value);
}
}
}
lastFrameTime = frame.Timestamp;
lastLargest = largest;
return(result);
}