private void ComputeVelocities(TrajectoryKinematics kinematics, CalibrationHelper calibrationHelper) { if (kinematics.Length <= 2) { PadVelocities(kinematics); return; } for (int i = 1; i < kinematics.Length - 1; i++) { PointF a = kinematics.Coordinates(i - 1); PointF b = kinematics.Coordinates(i + 1); float t = calibrationHelper.GetTime(2); kinematics.Speed[i] = (double)calibrationHelper.ConvertSpeed(GetSpeed(a, b, t, Component.Magnitude)); kinematics.HorizontalVelocity[i] = (double)calibrationHelper.ConvertSpeed(GetSpeed(a, b, t, Component.Horizontal)); kinematics.VerticalVelocity[i] = (double)calibrationHelper.ConvertSpeed(GetSpeed(a, b, t, Component.Vertical)); } PadVelocities(kinematics); double constantVelocitySpan = 40; MovingAverage filter = new MovingAverage(); kinematics.Speed = filter.FilterSamples(kinematics.Speed, calibrationHelper.CaptureFramesPerSecond, constantVelocitySpan, 1); kinematics.HorizontalVelocity = filter.FilterSamples(kinematics.HorizontalVelocity, calibrationHelper.CaptureFramesPerSecond, constantVelocitySpan, 1); kinematics.VerticalVelocity = filter.FilterSamples(kinematics.VerticalVelocity, calibrationHelper.CaptureFramesPerSecond, constantVelocitySpan, 1); }
private void ComputeAccelerations(TimeSeriesCollection tsc, CalibrationHelper calibrationHelper, Func <int, PointF> getCoord) { if (tsc.Length <= 4) { PadAccelerations(tsc); return; } // First pass: average speed over 2t centered on each data point. for (int i = 2; i < tsc.Length - 2; i++) { float t = calibrationHelper.GetTime(2); double acceleration = (tsc[Kinematics.LinearSpeed][i + 1] - tsc[Kinematics.LinearSpeed][i - 1]) / t; tsc[Kinematics.LinearAcceleration][i] = calibrationHelper.ConvertAccelerationFromVelocity((float)acceleration); double horizontalAcceleration = (tsc[Kinematics.LinearHorizontalVelocity][i + 1] - tsc[Kinematics.LinearHorizontalVelocity][i - 1]) / t; tsc[Kinematics.LinearHorizontalAcceleration][i] = calibrationHelper.ConvertAccelerationFromVelocity((float)horizontalAcceleration); double verticalAcceleration = (tsc[Kinematics.LinearVerticalVelocity][i + 1] - tsc[Kinematics.LinearVerticalVelocity][i - 1]) / t; tsc[Kinematics.LinearVerticalAcceleration][i] = calibrationHelper.ConvertAccelerationFromVelocity((float)verticalAcceleration); } PadAccelerations(tsc); // Second pass: extra smoothing derivatives. // This is only applied for high speed videos where the digitization is very noisy // due to the combination of increased time resolution and decreased spatial resolution. double constantAccelerationSpan = 50; MovingAverage filter = new MovingAverage(); double[] averagedAcceleration = filter.FilterSamples(tsc[Kinematics.LinearAcceleration], calibrationHelper.CaptureFramesPerSecond, constantAccelerationSpan, 2); double[] averagedHorizontalAcceleration = filter.FilterSamples(tsc[Kinematics.LinearHorizontalAcceleration], calibrationHelper.CaptureFramesPerSecond, constantAccelerationSpan, 2); double[] averagedVerticalAcceleration = filter.FilterSamples(tsc[Kinematics.LinearVerticalAcceleration], calibrationHelper.CaptureFramesPerSecond, constantAccelerationSpan, 2); for (int i = 0; i < tsc.Length; i++) { tsc[Kinematics.LinearAcceleration][i] = averagedAcceleration[i]; tsc[Kinematics.LinearHorizontalAcceleration][i] = averagedHorizontalAcceleration[i]; tsc[Kinematics.LinearVerticalAcceleration][i] = averagedVerticalAcceleration[i]; } }
private void ComputeVelocities(TimeSeriesCollection tsc, CalibrationHelper calibrationHelper, Func <int, PointF> getCoord) { if (tsc.Length <= 2) { PadVelocities(tsc); return; } for (int i = 1; i < tsc.Length - 1; i++) { PointF a = getCoord(i - 1); PointF b = getCoord(i + 1); float t = calibrationHelper.GetTime(2); tsc[Kinematics.LinearSpeed][i] = (double)calibrationHelper.ConvertSpeed(GetSpeed(a, b, t, Component.Magnitude)); tsc[Kinematics.LinearHorizontalVelocity][i] = (double)calibrationHelper.ConvertSpeed(GetSpeed(a, b, t, Component.Horizontal)); tsc[Kinematics.LinearVerticalVelocity][i] = (double)calibrationHelper.ConvertSpeed(GetSpeed(a, b, t, Component.Vertical)); } PadVelocities(tsc); // Second pass: apply extra smoothing to the derivatives. // This is only applied for high speed videos where the digitization is very noisy // due to the combination of increased time resolution and decreased spatial resolution. double constantVelocitySpan = 40; MovingAverage filter = new MovingAverage(); double[] averagedVelocity = filter.FilterSamples(tsc[Kinematics.LinearSpeed], calibrationHelper.CaptureFramesPerSecond, constantVelocitySpan, 1); double[] averagedHorizontalVelocity = filter.FilterSamples(tsc[Kinematics.LinearHorizontalVelocity], calibrationHelper.CaptureFramesPerSecond, constantVelocitySpan, 1); double[] averagedVerticalVelocity = filter.FilterSamples(tsc[Kinematics.LinearVerticalVelocity], calibrationHelper.CaptureFramesPerSecond, constantVelocitySpan, 1); for (int i = 0; i < tsc.Length; i++) { tsc[Kinematics.LinearSpeed][i] = averagedVelocity[i]; tsc[Kinematics.LinearHorizontalVelocity][i] = averagedHorizontalVelocity[i]; tsc[Kinematics.LinearVerticalVelocity][i] = averagedVerticalVelocity[i]; } }
private void ComputeAccelerations(TrajectoryKinematics kinematics, CalibrationHelper calibrationHelper) { if (kinematics.Length <= 4) { PadAccelerations(kinematics); return; } // First pass: average speed over 2t centered on each data point. for (int i = 2; i < kinematics.Length - 2; i++) { PointF p0 = kinematics.Coordinates(i - 2); PointF p2 = kinematics.Coordinates(i); PointF p4 = kinematics.Coordinates(i + 2); float t02 = calibrationHelper.GetTime(2); float t24 = calibrationHelper.GetTime(2); float t13 = calibrationHelper.GetTime(2); double acceleration = (kinematics.Speed[i + 1] - kinematics.Speed[i - 1]) / t13; kinematics.Acceleration[i] = calibrationHelper.ConvertAccelerationFromVelocity((float)acceleration); double horizontalAcceleration = (kinematics.HorizontalVelocity[i + 1] - kinematics.HorizontalVelocity[i - 1]) / t13; kinematics.HorizontalAcceleration[i] = calibrationHelper.ConvertAccelerationFromVelocity((float)horizontalAcceleration); double verticalAcceleration = (kinematics.VerticalVelocity[i + 1] - kinematics.VerticalVelocity[i - 1]) / t13; kinematics.VerticalAcceleration[i] = calibrationHelper.ConvertAccelerationFromVelocity((float)verticalAcceleration); } PadAccelerations(kinematics); double constantAccelerationSpan = 50; MovingAverage filter = new MovingAverage(); kinematics.Acceleration = filter.FilterSamples(kinematics.Acceleration, calibrationHelper.CaptureFramesPerSecond, constantAccelerationSpan, 2); kinematics.HorizontalAcceleration = filter.FilterSamples(kinematics.HorizontalAcceleration, calibrationHelper.CaptureFramesPerSecond, constantAccelerationSpan, 2); kinematics.VerticalAcceleration = filter.FilterSamples(kinematics.VerticalAcceleration, calibrationHelper.CaptureFramesPerSecond, constantAccelerationSpan, 2); }