调整图像在C＃中纵横比和作物中心图像所以不存在任何差距 [英] Resize image in C# with aspect ratio and crop central image so there are no gaps

问题描述

我试图调整用户上传的图片的一道风景尺寸如450瓦特和250H，同时保持纵横比，但要避免就像在旁边空白的纵向图像缩放后的图像，我想裁剪图像的中心，填补了调整大小的尺寸。

I'm trying to resize user uploaded images to a landscape dimensions e.g. 450w and 250h while maintaining aspect ratio, but to avoid resized images like portrait images having gaps on the side I would like to crop the centre of the image to fill the resized dimensions.

我发现很多code的来调整图像，同时保持纵横比，但不是我上面找，我希望有人可以提供帮助。

I have found plenty of code to resize images while maintaining aspect ratio but not what I am looking for above, I'm hoping someone can help.

推荐答案

您应该通过needToFill =真：

You should pass needToFill = true:

public static System.Drawing.Image FixedSize(Image image, int Width, int Height, bool needToFill)
        {
            #region много арифметики
            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;
            }
        }

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