使用asp.net改变网页上图片颜色比如灰色变彩色

#region 改变图片颜色 /// <summary> /// 改变图片的颜色 /// </summary> /// <param name="filePath">图片的完整路径</param> /// <param name="colorIndex">改变的颜色，true为灰色，false为彩色</param> public void update_pixelColor(string filePath, bool colorIndex) { Bitmap bmp = new Bitmap(Bitmap.FromFile(filePath)); int value = 0; for (int i = 0; i < bmp.Height; i++) { for (int j = 0; j < bmp.Width; j++) { if (colorIndex) value = this.GetGrayNumColor(bmp.GetPixel(j, i)); else value = this.GetHongNumColor(bmp.GetPixel(j, i)); bmp.SetPixel(j, i, Color.FromArgb(value, value, value)); } } bmp.Save(filePath); } /// <summary> /// 获取彩色单点像素 /// </summary> /// <param name="posClr">单点像素</param> /// <returns>int</returns> private int GetHongNumColor(Color posClr) { return (posClr.R * 19595 + posClr.G * 38469 + posClr.B * 7472) >> 16; } /// <summary> /// 获取灰色单点像素 /// </summary> /// <param name="posClr">单点像素</param> /// <returns>Color</returns> private int GetGrayNumColor(Color posClr) { //要改变ARGB return (posClr.R * 19595 + posClr.G * 38469 + posClr.B * 7472) >> 16; } #endregion 改变图片颜色