public MatchResult FindMatch(Mat queryMat)
{
try {
var queryDescriptors = DescriptorManager.ExtractDescriptor(queryMat);
const int Knn = 11;
using (var indices = new Mat(new Size(queryDescriptors.Rows, 2), DepthType.Cv32F, 2))
using (var dists = new Mat(new Size(queryDescriptors.Rows, 2), DepthType.Cv32F, 2)) {
IndexContext.CurrentFlannIndex.KnnSearch(queryDescriptors, indices, dists, Knn, 32);
var result = new Dictionary <Models.Image, QueryHit>();
for (int i = 0; i < indices.Rows; i++)
{
// filter out all inadequate pairs based on distance between pairs
if (dists.GetFloatValue(i, 0) < (0.6 * dists.GetFloatValue(i, 1)))
{
var pos = indices.GetIntValue(i, 0);
//CvInvoke.FindHomography();
if (IndexContext.CurrentMappingIndex.ContainsKey(pos))
{
var img = IndexContext.CurrentMappingIndex[pos];
if (!result.ContainsKey(img))
{
result.Add(img, new QueryHit {
Image = img
});
}
result[img].Hits++;
}
}
}
return(new MatchResult {
Matches = result.Where(x => x.Value.Hits > Threshold).OrderByDescending(x => x.Value.Hits).ToDictionary(x => x.Key, y => y.Value),
});
}
}
catch (Exception e) {
return(null);
}
}
public void BuildIndex()
{
var imageRepo = new LocalImagesRepository();
var images = imageRepo.GetAll();
var descriptors = new List <Mat>();
var indexMappning = new Dictionary <int, Image>();
var startIndex = 0;
foreach (var image in images)
{
var descriptor = DescriptorManager.ExtractDescriptor(image);
if (descriptor == null)
{
continue;
}
//descriptor.IsEnabledDispose = false;
descriptors.Add(descriptor);
image.IndexStart = startIndex;
image.IndexEnd = startIndex + descriptor.Size.Height - 1;
for (var a = image.IndexStart; a < image.IndexEnd; a++)
{
indexMappning.Add(a, image);
}
//set new startIndex
startIndex += descriptor.Rows;
}
IndexContext.CurrentMappingIndex = indexMappning;
var indexParams = new LshIndexParamses(10, 10, 0);
IndexContext.ConcatDescriptors = DescriptorManager.ConcatDescriptors(descriptors);
IndexContext.CurrentFlannIndex = new Index(IndexContext.ConcatDescriptors, indexParams);
}