public void CreateAndDispose()
{
using (var model = MarrHildrethHash.Create())
{
GC.KeepAlive(model);
}
}
public void CompareSameImage()
{
using (var model = MarrHildrethHash.Create())
using (var img1 = Image("lenna.png", ImreadModes.GrayScale))
{
double hash = model.Compare(img1, img1);
Assert.Equal(0, hash, 6);
}
}
public void CompareDifferentImage()
{
using (var model = MarrHildrethHash.Create())
using (var img1 = Image("lenna.png", ImreadModes.GrayScale))
using (var img2 = Image("building.jpg", ImreadModes.GrayScale))
{
var size = new Size(256, 256);
using (var scaledImg1 = img1.Resize(size))
using (var scaledImg2 = img2.Resize(size))
{
double hash = model.Compare(scaledImg1, scaledImg2);
Assert.Equal(264411, hash, 6);
}
}
}
public void Compute()
{
using (var model = MarrHildrethHash.Create())
using (var img = Image("lenna.png"))
using (var hash = new MatOfByte())
{
model.Compute(img, hash);
Assert.Equal(1, hash.Rows);
Assert.Equal(72, hash.Cols);
Assert.Equal(MatType.CV_8UC1, hash.Type());
var hashArray = hash.ToArray();
Assert.Equal(
new byte[] { 208, 54, 63, 31, 143, 199, 227, 241, 192, 124, 126, 39, 3, 205, 192, 124, 126, 63, 228, 150, 199, 194,
242, 254, 208, 143, 201, 105, 118, 57, 5, 191, 3, 99, 177, 224, 15, 137, 153, 58, 5, 129, 63, 193, 216, 228,
112, 100, 129, 176, 248, 255, 110, 7, 230, 16, 193, 231, 207, 135, 0, 150, 120, 5, 191, 60, 18, 114, 119, 131, 150, 31 },
hashArray);
}
}
/// <summary>
/// Created a perceptual hash for an image
/// </summary>
/// <param name="path"></param>
/// <returns>Binary string of the hash</returns>
public string GetPerceptualHash(string path)
{
using var img = CvInvoke.Imread(path);
var hashAlgorithm = new MarrHildrethHash();
var hash = new Mat();
hashAlgorithm.Compute(img, hash);
// Get the data from the unmanage memeory
var data = new byte[hash.Width * hash.Height];
Marshal.Copy(hash.DataPointer, data, 0, hash.Width * hash.Height);
// Concatenate the Hex values representation
string hexString = BitConverter.ToString(data);
Logging.LogVerbose($"EMGU created a hash: {hexString}");
return(hexString.Replace("-", ""));
}
