private double GetSizeDifferencePercentage(YoloTrackingItemExtended item1, YoloItem item2)
{
var area1 = item1.Width * item1.Height;
var area2 = item2.Width * item2.Height;
if (area1 == area2)
{
return(0);
}
if (area1 > area2)
{
var change1 = 100.0 * area2 / area1;
return(100 - change1);
}
var change = 100.0 * area1 / area2;
return(100 - change);
}
public IEnumerable <YoloTrackingItem> Analyse(IEnumerable <YoloItem> items)
{
_processIndex++;
if (_trackingItems.Count == 0)
{
foreach (var item in items)
{
var trackingItem = new YoloTrackingItemExtended(item, GetObjectId());
_trackingItems.Add(trackingItem.ObjectId, trackingItem);
}
return(new YoloTrackingItem[0]);
}
var trackingItems = new List <YoloTrackingItem>();
foreach (var item in items)
{
var bestMatch = _trackingItems.Values.Select(o => new
{
Item = o,
DistancePercentage = DistancePercentage(o.Center(), item.Center()),
SizeDifference = GetSizeDifferencePercentage(o, item)
})
.Where(o => !trackingItems.Select(x => x.ObjectId).Contains(o.Item.ObjectId) && o.DistancePercentage <= 15 && o.SizeDifference < 30)
.OrderBy(o => o.DistancePercentage)
.FirstOrDefault();
if (bestMatch == null || bestMatch.Item.ProcessIndex + 25 < _processIndex)
{
var trackingItem1 = new YoloTrackingItemExtended(item, GetObjectId())
{
ProcessIndex = _processIndex
};
_trackingItems.Add(trackingItem1.ObjectId, trackingItem1);
continue;
}
bestMatch.Item.X = item.X;
bestMatch.Item.Y = item.Y;
bestMatch.Item.Width = item.Width;
bestMatch.Item.Height = item.Height;
bestMatch.Item.ProcessIndex = _processIndex;
bestMatch.Item.IncreaseTrackingConfidence();
if (bestMatch.Item.TrackingConfidence >= 60)
{
var trackingItem = new YoloTrackingItem(item, bestMatch.Item.ObjectId);
trackingItems.Add(trackingItem);
}
}
var itemsWithoutHits = _trackingItems.Values.Where(o => o.ProcessIndex != _processIndex);
foreach (var item in itemsWithoutHits)
{
item.DecreaseTrackingConfidence();
}
return(trackingItems);
}
