使用宽高比和裁剪中心图像调整C#中的图像,使其没有间隙

时间:2012-04-25 20:55:44

标签: c# asp.net

我正在尝试将用户上传的图片调整为景观尺寸,例如450w和250h同时保持纵横比,但为了避免重新调整图像,如肖像图像侧面有间隙我想裁剪图像的中心以填充调整大小的尺寸。

我找到了大量的代码来调整图像大小,同时保持宽高比,但不是我想要的,我希望有人可以提供帮助。

1 个答案:

答案 0 :(得分:47)

你应该传递needToFill = true:

public static System.Drawing.Image FixedSize(Image image, int Width, int Height, bool needToFill)
        {
            #region calculations
            int sourceWidth = image.Width;
            int sourceHeight = image.Height;
            int sourceX = 0;
            int sourceY = 0;
            double destX = 0;
            double destY = 0;

            double nScale = 0;
            double nScaleW = 0;
            double nScaleH = 0;

            nScaleW = ((double)Width / (double)sourceWidth);
            nScaleH = ((double)Height / (double)sourceHeight);
            if (!needToFill)
            {
                nScale = Math.Min(nScaleH, nScaleW);
            }
            else
            {
                nScale = Math.Max(nScaleH, nScaleW);
                destY = (Height - sourceHeight * nScale) / 2;
                destX = (Width - sourceWidth * nScale) / 2;
            }

            if (nScale > 1)
                nScale = 1;

            int destWidth = (int)Math.Round(sourceWidth * nScale);
            int destHeight = (int)Math.Round(sourceHeight * nScale);
            #endregion

            System.Drawing.Bitmap bmPhoto = null;
            try
            {
                bmPhoto = new System.Drawing.Bitmap(destWidth + (int)Math.Round(2 * destX), destHeight + (int)Math.Round(2 * destY));
            }
            catch (Exception ex)
            {
                throw new ApplicationException(string.Format("destWidth:{0}, destX:{1}, destHeight:{2}, desxtY:{3}, Width:{4}, Height:{5}",
                    destWidth, destX, destHeight, destY, Width, Height), ex);
            }
            using (System.Drawing.Graphics grPhoto = System.Drawing.Graphics.FromImage(bmPhoto))
            {
                grPhoto.InterpolationMode = InterpolationMode.HighQualityBicubic;
                grPhoto.CompositingQuality = CompositingQuality.HighQuality;
                grPhoto.SmoothingMode = SmoothingMode.HighQuality;

                Rectangle to =  new System.Drawing.Rectangle((int)Math.Round(destX), (int)Math.Round(destY), destWidth, destHeight);
                Rectangle from = new System.Drawing.Rectangle(sourceX, sourceY, sourceWidth, sourceHeight);
                //Console.WriteLine("From: " + from.ToString());
                //Console.WriteLine("To: " + to.ToString());
                grPhoto.DrawImage(image, to, from, System.Drawing.GraphicsUnit.Pixel);

                return bmPhoto;
            }
        }