C＃图像缩放，同时preserving宽高比不同大小 [英] c# Image resizing to different size while preserving aspect ratio

问题描述

我试图同时preserving从原始图像显示比例，使新的图像看起来不挤压来调整图像。

I'm trying to resize an image while preserving the aspect ratio from the original image so the new image doesn't look squashed.

例如：

转换一个150 * 100的图像定为150 * 150的图像。结果
  高度的额外的50像素需要用一个白色的背景色填充。

Convert a 150*100 image into a 150*150 image.
The extra 50 pixels of the height need to be padded with a white background color.

这是当前code我使用。

This is the current code I am using.

它非常适用调整，但改变原始图像的宽高比南瓜新形象。

It works well for resizing but changing the aspect ratio of the original image squashes the new image.

private void resizeImage(string path, string originalFilename, 
                         int width, int height)
    {
        Image image = Image.FromFile(path + originalFilename);

        System.Drawing.Image thumbnail = new Bitmap(width, height);
        System.Drawing.Graphics graphic = 
                     System.Drawing.Graphics.FromImage(thumbnail);

        graphic.InterpolationMode = InterpolationMode.HighQualityBicubic;
        graphic.SmoothingMode = SmoothingMode.HighQuality;
        graphic.PixelOffsetMode = PixelOffsetMode.HighQuality;
        graphic.CompositingQuality = CompositingQuality.HighQuality;

        graphic.DrawImage(image, 0, 0, width, height);

        System.Drawing.Imaging.ImageCodecInfo[] info =
                         ImageCodecInfo.GetImageEncoders();
        EncoderParameters encoderParameters;
        encoderParameters = new EncoderParameters(1);
        encoderParameters.Param[0] = new EncoderParameter(Encoder.Quality,
                         100L);            
        thumbnail.Save(path + width + "." + originalFilename, info[1], 
                         encoderParameters);
    }

编辑：我想有图像填充，而不是裁剪

I'd like to have the image padded instead of cropped

推荐答案

我从这个学习的this $ C $的CProject文章。

static Image FixedSize(Image imgPhoto, int Width, int Height)
    {
        int sourceWidth = imgPhoto.Width;
        int sourceHeight = imgPhoto.Height;
        int sourceX = 0;
        int sourceY = 0;
        int destX = 0;
        int destY = 0;

        float nPercent = 0;
        float nPercentW = 0;
        float nPercentH = 0;

        nPercentW = ((float)Width / (float)sourceWidth);
        nPercentH = ((float)Height / (float)sourceHeight);
        if (nPercentH < nPercentW)
        {
            nPercent = nPercentH;
            destX = System.Convert.ToInt16((Width -
                          (sourceWidth * nPercent)) / 2);
        }
        else
        {
            nPercent = nPercentW;
            destY = System.Convert.ToInt16((Height -
                          (sourceHeight * nPercent)) / 2);
        }

        int destWidth = (int)(sourceWidth * nPercent);
        int destHeight = (int)(sourceHeight * nPercent);

        Bitmap bmPhoto = new Bitmap(Width, Height,
                          PixelFormat.Format24bppRgb);
        bmPhoto.SetResolution(imgPhoto.HorizontalResolution,
                         imgPhoto.VerticalResolution);

        Graphics grPhoto = Graphics.FromImage(bmPhoto);
        grPhoto.Clear(Color.Red);
        grPhoto.InterpolationMode =
                InterpolationMode.HighQualityBicubic;

        grPhoto.DrawImage(imgPhoto,
            new Rectangle(destX, destY, destWidth, destHeight),
            new Rectangle(sourceX, sourceY, sourceWidth, sourceHeight),
            GraphicsUnit.Pixel);

        grPhoto.Dispose();
        return bmPhoto;
    }

这篇关于C＃图像缩放，同时preserving宽高比不同大小的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！