在 PictureBox Form C# 中调整大小时丢失图像质量

Posted 2023-04-11

【中文标题】在 PictureBox Form C# 中调整大小时丢失图像质量

【英文标题】：Losing image quality when resize in PictureBox Form C#

【发布时间】：2021-09-20 01:36:13

【问题描述】：

我有一个没有边框的表单，只需要在窗口角落显示一个图像，图片尺寸为 9567 x 18012，大小为 62 MB，我在调整质量损失时在表单中使用 PictureBox，为什么？，我需要第三方库来显示尺寸和尺寸都很大的图像吗？

左图是带有我的图像的PictureBox，右图是带有te信息的原始图像

【参考方案1】：

使用以下代码缩小图片尺寸。

public void SetPictureBoxImage(string path)

    Image myImage = Image.FromFile(path, true);
    int width = 500;
    double ratio = (double)myImage.Width / (double)myImage.Height;
    int height = Convert.ToInt32(width / ratio);
           
    if (height > width)
    
        ratio = (double)myImage.Height / (double)myImage.Width;
        height = width;
        width = Convert.ToInt32(height / ratio);
    
    pictureBox1.Image = ResizeImage(myImage, width, height);

调整大小方法

public static Bitmap ResizeImage(Image image, int width, int height)

   var destRect = new Rectangle(0, 0, width, height);
   var destImage = new Bitmap(width, height);

   destImage.SetResolution(image.HorizontalResolution, image.VerticalResolution);
   using (var graphics = Graphics.FromImage(destImage))
   
      graphics.CompositingMode = CompositingMode.SourceCopy;
      graphics.CompositingQuality = CompositingQuality.HighQuality;
      graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
      graphics.SmoothingMode = SmoothingMode.HighQuality;
      graphics.PixelOffsetMode = PixelOffsetMode.HighQuality;

      using (var wrapMode = new ImageAttributes())
      
          wrapMode.SetWrapMode(WrapMode.TileFlipXY);
          graphics.DrawImage(image, destRect, 0, 0, image.Width, image.Height, GraphicsUnit.Pixel);
      
   

   return destImage;