自动去除图像扫描黑边

复制代码 代码如下:
/// <summary>
/// 自动去除图像扫描黑边
/// </summary>
/// <param name="fileName"></param>
public static void AutoCutBlackEdge(string fileName)
{
//打开图像
Bitmap bmp = OpenImage(fileName);

RemoveBlackEdge(bmp);
//保存图像
SaveImage(bmp, fileName);
}

private static byte[] rgbValues; // 目标数组内存

/// <summary>
/// 图像去黑边
/// </summary>
/// <param name="bmp"></param>
/// <returns></returns>
private static Bitmap RemoveBlackEdge(Bitmap bmp)
{
Rectangle rect = new Rectangle(0, 0, bmp.Width, bmp.Height);
BitmapData bmpData = bmp.LockBits(rect, ImageLockMode.ReadWrite, bmp.PixelFormat);

// 获取图像参数
int w = bmpData.Width;
int h = bmpData.Height;
int stride = bmpData.Stride; // 扫描线的宽度
double picByteSize = GetPicByteSize(bmp.PixelFormat);
int bWidth = (int)Math.Ceiling(picByteSize * w); //显示宽度
int offset = stride - bWidth; // 显示宽度与扫描线宽度的间隙
IntPtr ptr = bmpData.Scan0; // 获取bmpData的内存起始位置
int scanBytes = stride * h; // 用stride宽度，表示这是内存区域的大小

// 分别设置两个位置指针，指向源数组和目标数组
int posScan = 0;
rgbValues = new byte[scanBytes]; // 为目标数组分配内存
Marshal.Copy(ptr, rgbValues, 0, scanBytes); // 将图像数据拷贝到rgbValues中

bool isPass = true;
int i = 0, j = 0;
int cutW = (int)(bWidth * 0.02); //2%宽度（可修改）
int cutH = (int)(h * 0.02); //2%高度（可修改）
int posLen = (int)(picByteSize * 8); //继续查找深度为8的倍数（可修改）
//左边
for (i = 0; i < h; i++)
{
for (j = 0; j < bWidth; j++)
{
isPass = true;
if (rgbValues[posScan] < 255) rgbValues[posScan] = 255;

if (rgbValues[posScan + 1] == 255)
{
for (int m = 1; m <= posLen; m++)
{
if (rgbValues[posScan + m] < 255) isPass = false;
}
}
if (rgbValues[posScan + 1] < 255 || bWidth / 2 < j) isPass = false;
recCheck(ref rgbValues, posScan, h, stride, true);

posScan++;
if (j >= cutW && isPass) break;
}
// 跳过图像数据每行未用空间的字节，length = stride - width * bytePerPixel
if (j == bWidth) posScan += offset;
else posScan += (offset + bWidth - j - 1);
}
//右边
posScan = scanBytes - 1;
for (i = h - 1; i >= 0; i--)
{
posScan -= offset;
for (j = bWidth - 1; j >= 0; j--)
{
isPass = true;
if (rgbValues[posScan] < 255) rgbValues[posScan] = 255;

if (rgbValues[posScan - 1] == 255)
{
for (int m = 1; m <= posLen; m++)
{
if (rgbValues[posScan - m] < 255) isPass = false;
}
}
if (rgbValues[posScan - 1] < 255 || bWidth / 2 > j) isPass = false;
recCheck(ref rgbValues, posScan, h, stride, false);

posScan--;
if (cutH < (h - i))
if (j < (bWidth - cutW) && isPass) break;
}
// 跳过图像数据每行未用空间的字节，length = stride - width * bytePerPixel
if (j != -1) posScan -= j;
}

// 内存解锁
Marshal.Copy(rgbValues, 0, ptr, scanBytes);
bmp.UnlockBits(bmpData); // 解锁内存区域

return bmp;
}

/// <summary>
/// 上下去除黑边时，临近黑点去除
/// </summary>
/// <param name="rgbValues"></param>
/// <param name="posScan"></param>
/// <param name="h"></param>
/// <param name="stride"></param>
/// <param name="islLeft"></param>
private static void recCheck(ref byte[] rgbValues, int posScan, int h, int stride, bool islLeft)
{
int scanBytes = h * stride;
int cutH = (int)(h * 0.01); //临近最大1%高度（可修改）
for (int i = 1; i <= cutH; i++)
{
int befRow = 0;
if (islLeft && (posScan - stride * i) > 0)
{
befRow = posScan - stride * i;
}
else if (!islLeft && (posScan + stride * i) < scanBytes)
{
befRow = posScan + stride * i;
}
if (rgbValues[befRow] < 255) rgbValues[befRow] = 255;
else break;
}
}