protected void Exposure(string param)
{
if (inputImage == null)
{
return;
}
Dictionary <string, string> p = Util.ParseKeyValueList(param);
double gamma = 0.0;
if (p.Count > 0)
{
// gamma=<float-number>
Util.TryParse(p, "gamma", ref gamma);
// exp=<float-number>
// must not change the value if the 'exp' key is not present
Util.TryParse(p, "exp", ref exposure);
// sub=<sub-factor>
if (Util.TryParse(p, "sub", ref subFactor))
{
if (subFactor < 1)
{
subFactor = 1;
}
if (subFactor == 1)
{
if (inputImage != origInputImage)
{
inputImage = origInputImage;
}
}
else
if (inputImage.Width * subFactor != origInputImage.Width)
{
inputImage = new FloatImage(origInputImage);
inputImage.Resize(subFactor);
}
}
}
sw.Restart();
outputImage = inputImage.Exposure(outputImage, exposure, gamma);
sw.Stop();
labelStatus.Text = string.Format(CultureInfo.InvariantCulture, "{0:f1} EV, exp: {1} ms",
contrast, sw.ElapsedMilliseconds);
setImage(ref outputImage, outputImage);
}
/// <summary>
/// compute dct robust image hash
/// </summary>
/// <param name="image">An image to compute DCT hash.</param>
/// <returns>hash of type ulong</returns>
public static ulong ComputeDctHash(IByteImage image)
{
FloatImage img = image.Convolve(new FloatImage(7, 7, 1));
FloatImage resized = img.Resize(32, 32);
FloatImage coeff = _DctMatrix ?? (_DctMatrix = CreateDctMatrix(32));
FloatImage dctImage = coeff.MatrixMultiply(resized).MatrixMultiply(coeff, isTransposed: true);
float median = GetMedianOf64(dctImage);
ulong r = 0ul;
for (int y = 0; y < 8; y++)
{
for (int x = 0; x < 8; x++)
{
r |= dctImage[x + 1, y + 1] > median ? (1ul << (x + 8 * y)) : 0;
}
}
return(r);
}
