/// <summary>
/// Collects the labeling objects.
/// </summary>
/// <param name="count">The objects count.</param>
/// <param name="map">The objects labels map.</param>
/// <returns>The list of objects segments.</returns>
private SegmentInfo[] CollectObjects(int count, byte[] map)
{
int label = 0;
int position = 0;
int[] x1 = new int[count + 1];
int[] y1 = new int[count + 1];
int[] x2 = new int[count + 1];
int[] y2 = new int[count + 1];
long[] cx = new long[count + 1];
long[] cy = new long[count + 1];
long[] area = new long[count + 1];
for (int j = 1; j <= count; ++j)
{
x1[j] = this.width;
y1[j] = this.height;
}
for (int y = 0; y < this.height; ++y)
{
for (int x = 0; x < this.width; ++x, ++position)
{
label = map[position];
if (label == 0)
{
continue;
}
x1[label] = x < x1[label] ? x : x1[label];
x2[label] = x > x2[label] ? x : x2[label];
y1[label] = y < y1[label] ? y : y1[label];
y2[label] = y > y2[label] ? y : y2[label];
cx[label] += x;
cy[label] += y;
area[label]++;
}
}
double absoluteAreaThrehold = 0;
double absoluteWidthThrehold = 0;
double absoluteHeightThrehold = 0;
for (int i = 1; i <= count; ++i)
{
absoluteAreaThrehold = Math.Max(absoluteAreaThrehold, area[i]);
absoluteWidthThrehold = Math.Max(absoluteWidthThrehold, x2[i] - x1[i]);
absoluteHeightThrehold = Math.Max(absoluteHeightThrehold, y2[i] - y1[i]);
cx[i] /= area[i];
cy[i] /= area[i];
}
absoluteAreaThrehold = this.areaThreshold * absoluteAreaThrehold;
absoluteWidthThrehold = this.sizeThreshold * absoluteWidthThrehold;
absoluteHeightThrehold = this.sizeThreshold * absoluteHeightThrehold;
List <SegmentInfo> result = new List <SegmentInfo>();
for (int j = 1; j <= count; ++j)
{
if (area[j] < absoluteAreaThrehold || (x2[j] - x1[j]) < (absoluteWidthThrehold) || (y2[j] - y1[j]) < absoluteHeightThrehold)
{
continue;
}
SegmentInfo info = ComputeSegmentInfo(j, map, x1[j], x2[j], y1[j], y2[j], (int)cx[j], (int)cy[j]);
if (info != null)
{
result.Add(info);
}
}
return(result.ToArray());
}
/// <summary>
/// Extracts the objects from the specified image.
/// </summary>
/// <param name="image">The image.</param>
/// <param name="segments">The fingerprint segments.</param>
/// <param name="fingerImages">The cropped and rotated segments images.</param>
/// <returns><c>true</c> if extractions completes successfully; otherwise, <c>false</c>.</returns>
public bool Extract(Bitmap image, out SegmentInfo[] segments, out Image[] fingerImages)
{
if (!Extract(image, out segments))
{
fingerImages = new Image[segments.Length];
return(false);
}
fingerImages = new Image[segments.Length];
PointF[] vertices = new PointF[4];
Matrix transformation = new Matrix();
int[] limits = new int[4];
for (int i = 0; i < segments.Length; ++i)
{
SegmentInfo info = segments[i];
int halfWidth = info.Size.Width / 2;
int halfHeight = info.Size.Height / 2;
transformation.Reset();
transformation.Translate(info.Centroid.X, info.Centroid.Y);
transformation.Rotate(-info.Rotation);
vertices[0] = new PointF(-halfWidth, -halfHeight);
vertices[1] = new PointF(halfWidth, -halfHeight);
vertices[2] = new PointF(-halfWidth, halfHeight);
vertices[3] = new PointF(halfWidth, halfHeight);
limits[0] = int.MaxValue;
limits[1] = 0;
limits[2] = int.MaxValue;
limits[3] = 0;
transformation.TransformPoints(vertices);
for (int j = 0; j < 4; ++j)
{
limits[0] = (int)Math.Min(limits[0], vertices[j].X);
limits[1] = (int)Math.Max(limits[1], vertices[j].X);
limits[2] = (int)Math.Min(limits[2], vertices[j].Y);
limits[3] = (int)Math.Max(limits[3], vertices[j].Y);
}
int cropWidth = limits[1] - limits[0];
int cropHeight = limits[3] - limits[2];
Bitmap segmentImage = new Bitmap(info.Size.Width, info.Size.Height);
transformation.Reset();
transformation.Translate(-cropWidth / 2, -cropHeight / 2);
transformation.Rotate(info.Rotation, MatrixOrder.Append);
transformation.Translate(halfWidth, halfHeight, MatrixOrder.Append);
using (Graphics gfx = Graphics.FromImage(segmentImage))
{
gfx.Transform = transformation;
gfx.InterpolationMode = InterpolationMode.HighQualityBicubic;
gfx.SmoothingMode = SmoothingMode.HighQuality;
gfx.DrawImage(image, 0.0f, 0.0f, new Rectangle(limits[0], limits[2], cropWidth, cropHeight), GraphicsUnit.Pixel);
}
fingerImages[i] = segmentImage;
}
return(true);
}
