.net图片自动裁剪白边函数案例

浏览数：79 / 时间：2015年06月09日

1.项目要求上传白底的图片要进行裁剪白边，于是同事谢了个函数感觉很好用。

  #region 剪切白边
        /// <summary>
        /// 剪切白边
        /// </summary>
        /// <param name="p"></param>
        /// <returns></returns>
        public static Image Crop(Image p)
        { 
            int x, y ;//for use of X,Y Coordinates of pixels
            Bitmap b = new Bitmap(p); //image needed to crop
            Color c = new Color(); //pixel color for use of identifying if background
            int intLeft=0;//furthest left X coordinate
            int intRight=0;//furthest right X coordinate
            int intBottom =0;//furthest to the bottom Y coordinate
            int intTop =0;
            y = 0;
            while(y < b.Height) 
            {
                x = 0;
                while (x < b.Width) //loop through pixels on X axis until end of image width
                {
                    c = b.GetPixel(x, y); //Get the color of the pixel
                    if (c.R != 255&&c.R!=0 && c.G != 255&&c.G!=0 && c.B != 255&&c.B!=0)
                    {
                        if (c.R < 240 || c.G < 240 || c.B < 240)
                        {
                            //Determine if pixel is further left than the value we already have
                            if (intLeft == 0 || intLeft > x )
                            {
                                intLeft = x;
                            }
                            //Determine if pixel is further to the top than the value we already have
                            if (intTop == 0 || intTop > y )
                            {
                                intTop = y;
                            }
                            //Determine if pixel is further right than the value we already have
                            if (intRight <= b.Width && intRight < x )
                            {
                                intRight = x;
                            }
                            //Determine if pixel is further to the bottom than the value we already have
                            if (intBottom <= b.Height && intBottom < y )
                            {
                                intBottom = y;
                            }
                        }
                    }
                    x += 1;
                }
                y += 1;
            }
            int intNewWidth = intRight; //Establish width of new cropped image
            int intNewHeight = intBottom; //Establish height of new cropped image
            Bitmap imgCropped =new Bitmap(intNewWidth - intLeft + 2, intNewHeight - intTop + 2);
            Graphics objGraphics = Graphics.FromImage(imgCropped);
            //set the background color to white (you can choose what you like
            objGraphics.Clear(System.Drawing.Color.Transparent);
            int intStartTop = 1 - intTop; /// 40 + 5
            int intStartLeft = 1 - intLeft; /// 40 + 5
            //Draw the original image to your new cropped sized image
            objGraphics.DrawImage(b, intStartLeft, intStartTop);
            b.Dispose();
            objGraphics.Dispose();
            //return the Cropped image to the caller
            return imgCropped;
        }