C#图像灰度级拉伸的方法
本文实例讲述了C#图像灰度级拉伸的方法。分享给大家供大家参考。具体如下:
//定义图像灰度拉伸函数 private static Bitmap GrayLP (Bitmap a) { Rectangle rect = new Rectangle(0, 0, a.Width, a.Height); System.Drawing.Imaging.BitmapData srcData = a.LockBits(rect, System.Drawing.Imaging.ImageLockMode.ReadWrite, a.PixelFormat); IntPtr ptr = srcData.Scan0; int bytes = 0; if (a.PixelFormat == System.Drawing.Imaging.PixelFormat.Format8bppIndexed) { bytes = a.Width * a.Height; } else { bytes = a.Width * a.Height * 3; } byte[] grayValues = new byte[bytes]; System.Runtime.InteropServices.Marshal.Copy(ptr, grayValues, 0, bytes); byte n = 255, m = 0; double p; //计算最大和最小灰度级 for (int i = 0; i < bytes; i++) { //计算最小灰度级 if (n > grayValues[i]) { n = grayValues[i]; } //计算最大灰度级 if (m < grayValues[i]) { m = grayValues[i]; } } //得到斜率 p = 255.0 / (m - n); //灰度拉伸 for (int i = 0; i < bytes; i++) { grayValues[i] = (byte)(p * (grayValues[i] - n) + 0.5); } System.Runtime.InteropServices.Marshal.Copy(grayValues, 0, ptr, bytes); a.UnlockBits(srcData); return a; }
希望本文所述对大家的C#程序设计有所帮助。
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