/// <summary>
/// 图片转换灰度
/// </summary>
/// <param name="img"></param>
/// <param name="algo"></param>
/// <returns></returns>
public static Image ToGray(Image img, AlgorithmsType algo)
{
int width = img.Width;
int height = img.Height;
Bitmap bmp = new Bitmap(img);
//设定实例BitmapData相关信息
Rectangle rect = new Rectangle(0, 0, width, height);
ImageLockMode mode = ImageLockMode.ReadWrite;
PixelFormat format = PixelFormat.Format32bppArgb;
//锁定bmp到系统内存中
BitmapData data = bmp.LockBits(rect, mode, format);
//获取位图中第一个像素数据的地址
IntPtr ptr = data.Scan0;
int numBytes = width * height * 4;
byte[] rgbValues = new byte[numBytes];
//将bmp数据Copy到申明的数组中
Marshal.Copy(ptr, rgbValues, 0, numBytes);
for (int i = 0; i < rgbValues.Length; i += 4)
{
int value = 0;
switch (algo)
{
//最大值法
case AlgorithmsType.MaxValue:
value = rgbValues[i] > rgbValues[i + 1] ? rgbValues[i] : rgbValues[i + 1];
value = value > rgbValues[i + 2] ? value : rgbValues[i + 2];
break;
//平均值法
case AlgorithmsType.AverageValue:
value = (int)((rgbValues[i] + rgbValues[i + 1] + rgbValues[i + 2]) / 3);
break;
//加权平均值法
case AlgorithmsType.WeightAverage:
value = (int)(rgbValues[i] * 0.1 + rgbValues[i + 1] * 0.2
+ rgbValues[i + 2] * 0.7);
break;
}
//将数组中存放R、G、B的值修改为计算后的值
for (int j = 0; j < 3; j++)
{
rgbValues[i + j] = (byte)value;
}
}
//将数据Copy到内存指针
Marshal.Copy(rgbValues, 0, ptr, numBytes);
//从系统内存解锁bmp
bmp.UnlockBits(data);
return (Image)bmp;
}
/// <summary>
/// 灰度
/// </summary>
/// <param name="img"></param>
/// <param name="algo"></param>
/// <returns></returns>
public static Image Gray(Image img, AlgorithmsType algo)
{
int width = img.Width;
int height = img.Height;
Bitmap bmp = new Bitmap(img);
//设定实例BitmapData相关信息
Rectangle rect = new Rectangle(0, 0, width, height);
ImageLockMode mode = ImageLockMode.ReadWrite;
PixelFormat format = PixelFormat.Format32bppArgb;
//锁定bmp到系统内存中
BitmapData data = bmp.LockBits(rect, mode, format);
//获取位图中第一个像素数据的地址
IntPtr ptr = data.Scan0;
int numBytes = width * height * 4;
byte[] rgbValues = new byte[numBytes];
//将bmp数据Copy到申明的数组中
Marshal.Copy(ptr, rgbValues, 0, numBytes);
for (int i = 0; i < rgbValues.Length; i += 4)
{
int value = 0;
switch (algo)
{
//最大值法
case AlgorithmsType.MaxValue:
value = rgbValues[i] > rgbValues[i + 1] ? rgbValues[i] : rgbValues[i + 1];
value = value > rgbValues[i + 2] ? value : rgbValues[i + 2];
break;
//平均值法
case AlgorithmsType.AverageValue:
value = (int)((rgbValues[i] + rgbValues[i + 1] + rgbValues[i + 2]) / 3);
break;
//加权平均值法
case AlgorithmsType.WeightAverage:
value = (int)(rgbValues[i] * 0.1 + rgbValues[i + 1] * 0.2
+ rgbValues[i + 2] * 0.7);
break;
}
//将数组中存放R、G、B的值修改为计算后的值
for (int j = 0; j < 3; j++)
{
rgbValues[i + j] = (byte)value;
}
}
//将数据Copy到内存指针
Marshal.Copy(rgbValues, 0, ptr, numBytes);
//从系统内存解锁bmp
bmp.UnlockBits(data);
return((Image)bmp);
}