// our constructor for creating using 256 RGB values.
public static IntegralImage FromImageGrey(Bitmap image)
{
IntegralImage pic = new IntegralImage(image.Width, image.Height);
float rowsum = 0;
BitmapData dataIn = image.LockBits(new Rectangle(0, 0, image.Width, image.Height), ImageLockMode.ReadOnly, PixelFormat.Format24bppRgb);
unsafe
{
byte* pIn = (byte*)(dataIn.Scan0.ToPointer());
for (int y = 0; y < dataIn.Height; y++)
{
rowsum = 0;
for (int x = 0; x < dataIn.Width; x++)
{
int cb = (byte)(pIn[0]);
int cg = (byte)(pIn[1]);
int cr = (byte)(pIn[2]);
rowsum += (cR * cr + cG * cg + cB * cb) / 255f;
// integral image is rowsum + value above
if (y == 0)
pic[0, x] = rowsum;
else
pic[y, x] = rowsum + pic[y - 1, x];
pIn += 3;
}
pIn += dataIn.Stride - dataIn.Width * 3;
}
}
image.UnlockBits(dataIn);
return pic;
}
/// <summary>
/// Constructor with parameters
/// </summary>
/// <param name="thresh"></param>
/// <param name="octaves"></param>
/// <param name="init_sample"></param>
/// <param name="img"></param>
public FastHessian(float thresh, int octaves, int init_sample, IntegralImage img)
{
this.thresh = thresh;
this.octaves = octaves;
this.init_sample = init_sample;
this.img = img;
}
// Build descriptors for each interest point in the supplied list
public void DescribeInterestPoints(List<IPoint> ipts, bool upright, bool extended, IntegralImage img)
{
if (ipts.Count == 0)
return;
this.img = img;
foreach (IPoint ip in ipts)
{
// determine descriptor size
if (extended)
ip.descriptorLength = 128;
else
ip.descriptorLength = 64;
// if we want rotation invariance get the orientation
if (!upright)
GetOrientation(ip);
// Extract SURF descriptor
GetDescriptor(ip, upright, extended);
}
}
/// <summary>
/// Static one-call do it all method
/// </summary>
/// <param name="thresh"></param>
/// <param name="octaves"></param>
/// <param name="init_sample"></param>
/// <param name="img"></param>
/// <returns></returns>
public static List<IPoint> getIpoints(float thresh, int octaves, int init_sample, IntegralImage img)
{
FastHessian fh = new FastHessian(thresh, octaves, init_sample, img);
return fh.getIpoints();
}
// Static one-call do it all function
public static void DecribeInterestPoints(List<IPoint> ipts, bool upright, bool extended, IntegralImage img)
{
SurfDescriptor des = new SurfDescriptor();
des.DescribeInterestPoints(ipts, upright, extended, img);
}