/// <summary>
/// 集合中删除元素(线程安全), 必须调用base，否则会造成无限递归
/// </summary>
/// <param name="ts"></param>
public void Remove(LayerImage li)
{
lock (this.SyncRoot)
{
base.Remove(li);
}
}
/// <summary>
/// 集合中增加元素(线程安全), 必须调用base，否则会造成无限递归
/// </summary>
/// <param name="li">LayerImage元素</param>
public void Add(LayerImage li)
{
lock (this.SyncRoot)
{
base.Add(li);
}
}
/// <summary>
/// 求得(x,y)处x的偏导数
/// </summary>
/// <param name="l">层号</param>
/// <param name="x">x坐标</param>
/// <param name="y">y坐标</param>
/// <returns>偏导数值</returns>
private float Ix(int l, float x, float y)
{
LayerImage li = I[l];
return((li[x + 1, y] - li[x - 1, y]) / 2);
}
/// <summary>
/// 求得(x,y)处y的偏导数
/// </summary>
/// <param name="l">层号</param>
/// <param name="x">x坐标</param>
/// <param name="y">y坐标</param>
/// <returns>偏导数值</returns>
private float Iy(int l, float x, float y)
{
LayerImage li = I[l];
return((li[x, y + 1] - li[x, y - 1]) / 2);
}
/// <summary>
/// 将位图转换为层信息
/// </summary>
/// <param name="bmp">位图</param>
/// <returns>返回LayerImageCollection</returns>
public LayerImageCollection TransformBmpToLayerImg(Bitmap bmp)
{
if (bmp == null || bmp.PixelFormat != PixelFormat.Format8bppIndexed)
{
throw new Exception("原位图为空或者不是灰度图。");
}
int width = bmp.Width;
int height = bmp.Height;
Rectangle rect = new Rectangle(0, 0, width, height);
BitmapData bmpdata = bmp.LockBits(rect, ImageLockMode.ReadOnly, bmp.PixelFormat);
// Stride为位图中每一行以4字节对齐的行宽
int strideSource = bmpdata.Stride;
byte[] byteData = new byte[width * height];
LayerImage li = null;
LayerImageCollection layerCollection = null;
unsafe
{
byte *ptr = (byte *)bmpdata.Scan0.ToPointer();
for (int row = 0; row < height; row++)
{
for (int col = 0; col < width; col++)
{
// 位图的在内存中的排列是从左到右，从下到上的，但BitmapData貌似做了优化，把位图数据在内存中的排列
// 顺序改为与坐标系一致，即从左到右、从上到下
byteData[col + row * width] = *ptr;
ptr++;
}
}
bmp.UnlockBits(bmpdata);
}
layerCollection = new LayerImageCollection();
li = new LayerImage(byteData, width, height);
layerCollection.Add(li); // 加入I的第0层数据
for (int l = 1; l < LN; l++)
{
int w, h; // 当前层图像的宽和高
// width和height为前一层图像的宽和高
w = (width + 1) / 2;
h = (height + 1) / 2;
byteData = new byte[w * h];
for (int row = 0; row < h; row++)
{
for (int col = 0; col < w; col++)
{
int leftX = 2 * col - 1;
int rightX = 2 * col + 1;
int lowY = 2 * row - 1;
int upY = 2 * row + 1;
int centerX = 2 * col;
int centerY = 2 * row;
if (leftX < 0)
{
leftX = 0;
}
if (rightX >= width)
{
rightX = width - 1;
}
if (lowY < 0)
{
lowY = 0;
}
if (upY >= height)
{
upY = height - 1;
}
// 根据上一层的数据生成当前层的数据
byteData[col + row * w] = (byte)(0.25 * li.ImageData[centerX + centerY * width] +
0.125 * (li.ImageData[leftX + centerY * width] + li.ImageData[rightX + centerY * width] +
li.ImageData[centerX + lowY * width] + li.ImageData[centerX + upY * width]) +
0.0625 * (li.ImageData[leftX + lowY * width] + li.ImageData[rightX + lowY * width] +
li.ImageData[leftX + upY * width] + li.ImageData[rightX + upY * width]));
}
}
li = new LayerImage(byteData, w, h);
layerCollection.Add(li);
width = w;
height = h;
}
return(layerCollection);
}
