public static float[,] DCT_1(ImageBlock imageBlock)
{
var block = imageBlock.Data;
var n = imageBlock.Width;
var cosMatrix = CountCosMatrixFor(n);
var result = new float[n, n];
var value = 0f;
var subValue = 0f;
var C_0 = (float)(1 / Math.Sqrt(n));
var C_I = (float)Math.Sqrt(2f / n);
for (var u = 0; u < n; u++)
{
for (var v = 0; v < n; v++)
{
for (var i = 0; i < n; i++)
{
for (var j = 0; j < n; j++)
{
subValue += cosMatrix[v, j] * block[i, j];
}
value += cosMatrix[u, i] * subValue;
subValue = 0f;
}
result[u, v] = (u == 0 ? C_0 : C_I) * (v == 0 ? C_0 : C_I) * value;
value = 0f;
}
}
return(result);
}
public Complex[,] Transform(ImageBlock block)
{
var matrix = MatrixUtils <Complex> .ToComplexMatrix(block.Data);
var N = matrix.GetLength(0);
var result = new Complex[N, N];
var vector = new Complex[N];
for (var i = 0; i < N; i++)
{
for (var j = 0; j < N; j++)
{
vector[j] = matrix[i, j];
}
vector = Transform(vector);
for (var j = 0; j < N; j++)
{
result[i, j] = vector[j];
}
}
for (var i = 0; i < N; i++)
{
for (var j = 0; j < N; j++)
{
vector[j] = result[j, i];
}
vector = Transform(vector);
for (var j = 0; j < N; j++)
{
result[j, i] = vector[j];
}
}
return(result);
}
public static void Unshift(ImageBlock imageBlock)
{
var data = imageBlock.Data;
for (var i = 0; i < imageBlock.Width; i++)
{
for (var j = 0; j < imageBlock.Height; j++)
{
data[i, j] += 128;
}
}
}
public static ImageBlock FromAvaraged(ImageBlock avaraged)
{
var data = new int[avaraged.Width * 2, avaraged.Height * 2];
for (int k = 0; k < avaraged.Width * 2; k++)
{
for (int t = 0; t < avaraged.Height * 2; t++)
{
data[k, t] = avaraged.data[k / 2, t / 2];
}
}
return(new ImageBlock(data));
}
public static YCbCrPixel[,] Merge(ImageBlock y, ImageBlock cb, ImageBlock cr)
{
var pixels = new YCbCrPixel[y.Width, y.Height];
for (var i = 0; i < y.Width; i++)
{
for (var j = 0; j < y.Height; j++)
{
pixels[i, j] = new YCbCrPixel(y.Data[i, j], cb.Data[i, j], cr.Data[i, j]);
}
}
return(pixels);
}
public static Complex[,] HaarTransform(ImageBlock imageBlock, int p)
{
Complex[,] matrix = MathUtils.ToComplexMatrix(imageBlock.Data);
int w = matrix.GetLength(0);
int h = matrix.GetLength(1);
while (w >= p && h >= p)
{
HaarTransform(matrix, p, w, h);
w /= p;
h /= p;
}
return(matrix);
}
public static float[,] DCT(ImageBlock imageBlock)
{
var matrix = imageBlock.Data;
var N = matrix.GetLength(0);
var result = new float[N, N];
var vector = new float[N];
for (var i = 0; i < N; i++)
{
for (var j = 0; j < N; j++)
{
vector[j] = matrix[i, j];
}
if (vector.Length == 8)
{
vector = DCT_d1_Optimized(vector);
}
else
{
vector = DCT_d1_NotOptimized(vector);
}
for (var j = 0; j < N; j++)
{
result[i, j] = vector[j];
}
}
for (var i = 0; i < N; i++)
{
for (var j = 0; j < N; j++)
{
vector[j] = result[j, i];
}
if (vector.Length == 8)
{
vector = DCT_d1_Optimized(vector);
}
else
{
vector = DCT_d1_NotOptimized(vector);
}
for (var j = 0; j < N; j++)
{
result[j, i] = vector[j];
}
}
return(result);
}
public ImageBlock Average(ImageBlock imageBlock)
{
var w = imageBlock.Width;
var h = imageBlock.Height;
if (w % 4 != 0 && h % 4 != 0)
{
return(imageBlock);
}
var array = imageBlock.Data;
float average;
for (var i = 0; i < w; i += 2)
{
for (var j = 0; j < h; j += 2)
{
average = (array[i, j] + array[i + 1, j] + array[i, j + 1] + array[i + 1, j + 1]) / 4;
array[i, j] = array[i + 1, j] = array[i, j + 1] = array[i + 1, j + 1] = (int)average;
}
}
return(imageBlock);
}