public void SetBitsTest()
{
const int Size = 3 * 64;
ulong[] y = new ulong[3];
for (int count = 1; count < Size; count++)
{
for (int pos = 0; pos < Size - count; pos++)
{
y[0] = y[1] = y[2] = 0;
BitUtils.SetBits(count, y, pos);
Assert.AreEqual(count, BitUtils.CountOneBits(Size, y, 0));
Assert.AreEqual(pos, BitUtils.BitScanOneForward(Size, y, 0));
Assert.AreEqual(pos + count - 1, BitUtils.BitScanOneReverse(Size, y, Size - 1));
Assert.AreEqual(pos + count == Size ? -1 : pos + count, BitUtils.BitScanZeroForward(Size - pos, y, pos));
Assert.AreEqual(pos == 0 ? -1 : pos - 1, BitUtils.BitScanZeroReverse(pos + count, y, pos + count - 1));
}
}
}
/// <summary>
/// Cleans scan border noise from the <see cref="Image"/>.
/// </summary>
/// <param name="maxNoiseWidth">The maximum width of the noise, in inches.</param>
/// <param name="maxNoiseHeight">The maximum height of the noise, in inches.</param>
/// <returns>
/// A new cleaned <see cref="Image"/>.
/// </returns>
public Image CleanOverscan(float maxNoiseWidth, float maxNoiseHeight)
{
int width = this.Width;
int height = this.Height;
int stride1 = this.Stride1;
int stride = this.Stride;
Image dst = this.Copy(null, true);
ulong[] bits = dst.Bits;
int maxwidth = (int)((maxNoiseWidth * this.HorizontalResolution) + 0.5f);
if (maxwidth > 0)
{
ClearLeft(FindLeft(maxwidth));
ClearRight(FindRight(maxwidth));
}
int maxheight = (int)((maxNoiseHeight * this.VerticalResolution) + 0.5f);
if (maxheight > 0)
{
ClearTop(FindTop(maxheight));
ClearBottom(FindBottom(maxheight));
}
return(dst);
int[] FindLeft(int maxlen)
{
int scanlen = Core.MinMax.Min(width, maxlen);
int[] lengths = new int[height];
for (int iy = 0, pos = 0; iy < height; iy++, pos += stride1)
{
int len = BitUtils.BitScanZeroForward(scanlen, bits, pos);
lengths[iy] = len == -1 ? 0 : len - pos + 1;
}
return(lengths);
}
int[] FindRight(int maxlen)
{
int scanlen = Core.MinMax.Min(width, maxlen);
int[] lengths = new int[height];
for (int iy = 0, pos = width - 1; iy < height; iy++, pos += stride1)
{
int len = BitUtils.BitScanZeroReverse(scanlen, bits, pos);
lengths[iy] = len == -1 ? 0 : pos - len + 1;
}
return(lengths);
}
int[] FindTop(int maxlen)
{
int scanlen = Core.MinMax.Min(height, maxlen);
int[] lengths = Vectors.Create(width, scanlen);
for (int ix = 0; ix < width; ix++)
{
ulong mask = BitUtils.SetBit(0ul, ix & 63);
for (int iy = 0, off = ix >> 6; iy < scanlen; iy++, off += stride)
{
if ((bits[off] & mask) == 0)
{
lengths[ix] = iy;
break;
}
}
}
return(lengths);
}
int[] FindBottom(int maxlen)
{
int scanlen = Core.MinMax.Min(height, maxlen);
int[] lengths = Vectors.Create(width, scanlen);
int size = stride * height;
for (int ix = 0; ix < width; ix++)
{
ulong mask = BitUtils.SetBit(0ul, ix & 63);
for (int iy = 0, off = size - stride + (ix >> 6); iy < scanlen; iy++, off -= stride)
{
if ((bits[off] & mask) == 0)
{
lengths[ix] = iy;
break;
}
}
}
return(lengths);
}
void ClearLeft(int[] lengths)
{
for (int iy = 0, off = 0; iy < height; iy++, off += stride1)
{
int len = lengths[iy];
if (len != 0)
{
BitUtils.ResetBits(len, bits, off);
}
}
}
void ClearRight(int[] lengths)
{
for (int iy = 0, off = width; iy < height; iy++, off += stride1)
{
int len = lengths[iy];
if (len != 0)
{
BitUtils.ResetBits(len, bits, off - len);
}
}
}
void ClearTop(int[] lengths)
{
for (int ix = 0; ix < width; ix++)
{
int len = lengths[ix];
if (len != 0)
{
ulong mask = ~BitUtils.SetBit(0ul, ix & 63);
Vectors.AndC(len, mask, bits, ix >> 6, stride);
}
}
}
void ClearBottom(int[] lengths)
{
int size = stride * height;
for (int ix = 0; ix < width; ix++)
{
int len = lengths[ix];
if (len != 0)
{
ulong mask = ~BitUtils.SetBit(0ul, ix & 63);
Vectors.AndC(len, mask, bits, size - (len * stride) + (ix >> 6), stride);
}
}
}
}
