c#图片色阶调整、亮度调整

static void Main() { Bitmap aa = file2img("test.jpg"); Bitmap cc = img_color_gradation(aa,100,0,0); img2file(cc, "test1.jpg"); }

色阶调整代码

public static unsafe Bitmap img_color_gradation(Bitmap src, int r, int g, int b) { int width = src.Width; int height = src.Height; Bitmap back = new Bitmap(width, height); Rectangle rect = new Rectangle(0, 0, width, height); //这种速度最快 BitmapData bmpData = src.LockBits(rect, ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);//24位rgb显示一个像素，即一个像素点3个字节，每个字节是BGR分量。Format32bppRgb是用4个字节表示一个像素 byte* ptr = (byte*)(bmpData.Scan0); for (int j = 0; j < height; j++) { for (int i = 0; i < width; i++) { //ptr[2]为r值，ptr[1]为g值，ptr[0]为b值 int red = ptr[2] + r; if (red > 255) red = 255; if (red < 0) red = 0; int green = ptr[1] + g; if (green > 255) green = 255; if (green < 0) green = 0; int blue = ptr[0] + b; if (blue > 255) blue = 255; if (blue < 0) blue = 0; back.SetPixel(i, j, Color.FromArgb(red, green, blue)); ptr += 3; //Format24bppRgb格式每个像素占3字节 } ptr += bmpData.Stride - bmpData.Width * 3;//每行读取到最后“有用”数据时，跳过未使用空间XX } src.UnlockBits(bmpData); return back; }

图片读取，和存储函数

//图片读取 public static Bitmap file2img(string filepath) { Bitmap b = new Bitmap(filepath); return b; } //图片生成 public static void img2file(Bitmap b, string filepath) { b.Save(filepath); }