如何将图像转换为字节数组

Question

谁能建议我如何将图像转换为字节数组，反之亦然？

我正在开发 WPF 应用程序并使用流阅读器。

Answer 1

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# Image to Byte Array and Byte Array to Image Converter Class

Answer 2

要将 Image 对象转换为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

另一种从图像路径获取字节数组的方法是

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

Answer 4

这是我目前正在使用的。我尝试过的其他一些技术并不是最佳的，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 文件中获取图像，您应该使用 File.ReadAllBytes() 将文件读入字节数组：

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

这避免了与希望其源流保持打开状态的位图相关的问题，以及一些针对导致源文件保持锁定的问题的建议解决方法。

Answer 5

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 6

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。

希望这会有所帮助。

您可以找到更多信息和示例代码here。

Answer 7

您只想将像素或整个图像（包括标题）作为字节数组吗？

对于像素：在位图上使用CopyPixels 方法。比如：

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 来在流中携带字节，则该方法将不会返回任何内容。确保引用 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

Answer 9

代码：

using System.IO;

byte[] img = File.ReadAllBytes(openFileDialog1.FileName);

Answer 10

这是用于将任何类型（例如 PNG、JPG、JPEG）的图像转换为字节数组的代码

   public static byte[] imageConversion(string imageName){            


        //Initialize a file stream to read the image file
        FileStream fs = new FileStream(imageName, FileMode.Open, FileAccess.Read);

        //Initialize a byte array with size of stream
        byte[] imgByteArr = new byte[fs.Length];

        //Read data from the file stream and put into the byte array
        fs.Read(imgByteArr, 0, Convert.ToInt32(fs.Length));

        //Close a file stream
        fs.Close();

        return imageByteArr
    }

Answer 11

将图像转换为字节数组。代码如下。

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

将Byte数组转换为Image。代码如下。代码是Image Save中的句柄A Generic error occurred in GDI+。

public void SaveImage(string base64String, string filepath)
{
    // image convert to base64string is base64String 
    //File path is which path to save the image.
    var bytess = Convert.FromBase64String(base64String);
    using (var imageFile = new FileStream(filepath, FileMode.Create))
    {
        imageFile.Write(bytess, 0, bytess.Length);
        imageFile.Flush();
    }
}

Answer 12

此代码从 SQLSERVER 2012 中的表中检索前 100 行，并将每行的图片保存为本地磁盘上的文件

 public void SavePicture()
    {
        SqlConnection con = new SqlConnection("Data Source=localhost;Integrated security=true;database=databasename");
        SqlDataAdapter da = new SqlDataAdapter("select top 100 [Name] ,[Picture] From tablename", con);
        SqlCommandBuilder MyCB = new SqlCommandBuilder(da);
        DataSet ds = new DataSet("tablename");
        byte[] MyData = new byte[0];
        da.Fill(ds, "tablename");
        DataTable table = ds.Tables["tablename"];
           for (int i = 0; i < table.Rows.Count;i++ )               
               {
                DataRow myRow;
                myRow = ds.Tables["tablename"].Rows[i];
                MyData = (byte[])myRow["Picture"];
                int ArraySize = new int();
                ArraySize = MyData.GetUpperBound(0);
                FileStream fs = new FileStream(@"C:\NewFolder\" + myRow["Name"].ToString() + ".jpg", FileMode.OpenOrCreate, FileAccess.Write);
                fs.Write(MyData, 0, ArraySize);
                fs.Close();
               }

    }

请注意：具有 NewFolder 名称的目录应存在于 C:\