如何将图像转换为字节数组

Question

任何人都可以建议我如何将图像转换为字节数组,反之亦然？

如果有人有一些代码样本来帮助我,那就太好了.

我正在开发一个WPF应用程序并使用流阅读器.

Answer 1

用于将图像更改为字节数组的示例代码

public byte[] ImageToByteArray(System.Drawing.Image imageIn)
{
   using (var ms = new MemoryStream())
   {
      imageIn.Save(ms,imageIn.RawFormat);
      return  ms.ToArray();
   }
}

C#图像到字节数组和字节数组到图像转换器类

Answer 2

对于转换Image对象,byte[]您可以执行以下操作:

public static byte[] converterDemo(Image x)
{
    ImageConverter _imageConverter = new ImageConverter();
    byte[] xByte = (byte[])_imageConverter.ConvertTo(x, typeof(byte[]));
    return xByte;
}

Answer 3

从图像路径获取字节数组的另一种方法是

byte[] imgdata = System.IO.File.ReadAllBytes(HttpContext.Current.Server.MapPath(path));

Answer 4

试试这个:

public byte[] imageToByteArray(System.Drawing.Image imageIn)
{
    MemoryStream ms = new MemoryStream();
    imageIn.Save(ms,System.Drawing.Imaging.ImageFormat.Gif);
    return ms.ToArray();
}

public Image byteArrayToImage(byte[] byteArrayIn)
{
    MemoryStream ms = new MemoryStream(byteArrayIn);
    Image returnImage = Image.FromStream(ms);
    return returnImage;
}

Answer 5

您可以使用File.ReadAllBytes()方法将任何文件读入字节数组.要将字节数组写入文件,只需使用File.WriteAllBytes()方法.

希望这可以帮助.

您可以在此处找到更多信息和示例代码.

Answer 6

这是我目前正在使用的.我尝试过的其他一些技术并非非最佳,因为它们改变了像素的位深度(24位与32位)或忽略了图像的分辨率(dpi).

  // ImageConverter object used to convert byte arrays containing JPEG or PNG file images into 
  //  Bitmap objects. This is static and only gets instantiated once.
  private static readonly ImageConverter _imageConverter = new ImageConverter();

图像到字节数组:

  /// <summary>
  /// Method to "convert" an Image object into a byte array, formatted in PNG file format, which 
  /// provides lossless compression. This can be used together with the GetImageFromByteArray() 
  /// method to provide a kind of serialization / deserialization. 
  /// </summary>
  /// <param name="theImage">Image object, must be convertable to PNG format</param>
  /// <returns>byte array image of a PNG file containing the image</returns>
  public static byte[] CopyImageToByteArray(Image theImage)
  {
     using (MemoryStream memoryStream = new MemoryStream())
     {
        theImage.Save(memoryStream, ImageFormat.Png);
        return memoryStream.ToArray();
     }
  }

字节数组到图像:

  /// <summary>
  /// Method that uses the ImageConverter object in .Net Framework to convert a byte array, 
  /// presumably containing a JPEG or PNG file image, into a Bitmap object, which can also be 
  /// used as an Image object.
  /// </summary>
  /// <param name="byteArray">byte array containing JPEG or PNG file image or similar</param>
  /// <returns>Bitmap object if it works, else exception is thrown</returns>
  public static Bitmap GetImageFromByteArray(byte[] byteArray)
  {
     Bitmap bm = (Bitmap)_imageConverter.ConvertFrom(byteArray);

     if (bm != null && (bm.HorizontalResolution != (int)bm.HorizontalResolution ||
                        bm.VerticalResolution != (int)bm.VerticalResolution))
     {
        // Correct a strange glitch that has been observed in the test program when converting 
        //  from a PNG file image created by CopyImageToByteArray() - the dpi value "drifts" 
        //  slightly away from the nominal integer value
        bm.SetResolution((int)(bm.HorizontalResolution + 0.5f), 
                         (int)(bm.VerticalResolution + 0.5f));
     }

     return bm;
  }

编辑:要从jpg或png文件获取图像,您应该使用File.ReadAllBytes()将文件读入字节数组:

 Bitmap newBitmap = GetImageFromByteArray(File.ReadAllBytes(fileName));

这避免了与Bitmap相关的问题,希望其源流保持打开状态,并且一些建议的解决方法是导致源文件保持锁定的问题.

Answer 7

您是否只想将像素或整个图像(包括标题)作为字节数组？

对于像素:使用CopyPixels位图上的方法.就像是:

var bitmap = new BitmapImage(uri);

//Pixel array
byte[] pixels = new byte[width * height * 4]; //account for stride if necessary and whether the image is 32 bit, 16 bit etc.

bitmap.CopyPixels(..size, pixels, fullStride, 0); 

Answer 8

如果您不引用 imageBytes 以在流中携带字节，则该方法将不会返回任何内容。确保您引用 imageBytes = m.ToArray();

    public static byte[] SerializeImage() {
        MemoryStream m;
        string PicPath = pathToImage";

        byte[] imageBytes;
        using (Image image = Image.FromFile(PicPath)) {
            
            using ( m = new MemoryStream()) {

                image.Save(m, image.RawFormat);
                imageBytes = new byte[m.Length];
               //Very Important    
               imageBytes = m.ToArray();
                
            }//end using
        }//end using

        return imageBytes;
    }//SerializeImage