/// <summary>Initializes a new instance of the <see cref="Bitmap32"/> class.</summary>
/// <param name="width">Width in pixel.</param>
/// <param name="height">Height in pixel.</param>
public Bitmap32(int width, int height)
{
if (Loader == null)
{
throw new Exception("No valid IBitmap32Loader found!");
}
bitmap = Loader.Create(width, height);
}
/// <summary>Creates a bitmap instance from the specified Bitmap32.</summary>
public static Bitmap ToGdiBitmap(this IBitmap32 other)
{
if (other is GdiBitmap32)
{
return(((GdiBitmap32)other).Bitmap);
}
using var ms = new MemoryStream();
other.Save(ms);
ms.Position = 0;
return(ToGdiBitmap(Image.FromStream(ms)));
}
/// <summary>
/// Converts a bitmap
/// </summary>
/// <param name="bitmap"></param>
/// <returns></returns>
public static SKBitmap Convert(IBitmap32 bitmap)
{
if (bitmap is SkiaBitmap32)
{
return(((SkiaBitmap32)bitmap).bitmap);
}
using (MemoryStream ms = new MemoryStream())
{
bitmap.Save(ms);
ms.Position = 0;
return(SKBitmap.Decode(ms));
}
}
/// <summary>
/// Creates a 32x32 fingerprint for the specified bitmap.
/// </summary>
/// <param name="bitmap">The bitmap.</param>
/// <returns>Returns a fingerprint with 6 bits per pixel (32 px = 6144 bit = 768 byte = 1024 base32 chars).</returns>
public static FingerPrint Create(IBitmap32 bitmap)
{
using (Bitmap32 thumb = bitmap.Resize(32, 32, ResizeMode.TouchFromInside))
{
ARGBImageData data = thumb.Data;
using (var ms = new MemoryStream())
{
// calculate fingerprint and distance matrix
var writer = new BitStreamWriter(ms);
float[] distanceMatrix = new float[16];
{
int x = 0, y = 0;
ARGB last = 0;
foreach (ARGB pixel in data.Data)
{
if (++x > 15)
{
x = 0;
++y;
}
int r = pixel.Red >> 6;
int g = pixel.Green >> 6;
int b = pixel.Blue >> 6;
writer.WriteBits(r, 2);
writer.WriteBits(g, 2);
writer.WriteBits(b, 2);
unchecked
{
int i = ((y << 1) & 0xC) + (x >> 2);
float distance = Math.Abs(pixel.GetDistance(last));
distanceMatrix[i] += distance;
last = pixel;
}
}
}
// normalize matrix
float maxDistance = distanceMatrix.Max();
for (int i = 0; i < distanceMatrix.Length; i++)
{
distanceMatrix[i] /= maxDistance;
}
// calculate blocks
uint[] blocks = new uint[4];
int[] index = new int[] { 0, 2, 8, 10 };
for (int i = 0; i < 4; i++)
{
int idx = index[i];
uint blockValue = (uint)(255 * distanceMatrix[idx]) << 24;
blockValue |= (uint)(255 * distanceMatrix[idx + 1]) << 16;
blockValue |= (uint)(255 * distanceMatrix[idx + 4]) << 8;
blockValue |= (uint)(255 * distanceMatrix[idx + 5]);
blocks[i] = blockValue;
}
/*
* uint b1 = (uint)(uint.MaxValue * (distanceMatrix[0] + distanceMatrix[1] + distanceMatrix[4] + distanceMatrix[5]) /4);
* uint b2 = (uint)(uint.MaxValue * (distanceMatrix[3] + distanceMatrix[2] + distanceMatrix[7] + distanceMatrix[6]) / 4);
* uint b3 = (uint)(uint.MaxValue * (distanceMatrix[12] + distanceMatrix[13] + distanceMatrix[8] + distanceMatrix[9]) / 4);
* uint b4 = (uint)(uint.MaxValue * (distanceMatrix[15] + distanceMatrix[14] + distanceMatrix[11] + distanceMatrix[10]) / 4);
*/
return(new FingerPrint(32, blocks, ms.ToArray()));
}
}
}
/// <summary>Initializes a new instance of the <see cref="Bitmap32"/> class.</summary>
/// <param name="bitmap"></param>
public Bitmap32(IBitmap32 bitmap)
{
this.bitmap = bitmap;
}
/// <summary>
/// Disposes the image.
/// </summary>
public virtual void Dispose()
{
bitmap?.Dispose();
bitmap = null;
}
/// <summary>
/// Creates a new SkiaBitmap
/// </summary>
/// <param name="bitmap"></param>
public SkiaBitmap32(IBitmap32 bitmap)
: this(Convert(bitmap))
{
}
/// <summary>Initializes a new instance of the <see cref="GdiBitmap32"/> class.</summary>
/// <param name="bitmap"></param>
public GdiBitmap32(IBitmap32 bitmap)
: this(GdiBitmap32Extensions.ToGdiBitmap(bitmap))
{
}
