如何將圖像轉換為字節數組

Question

任何人都可以建議我如何將圖像轉換為字節數組，反之亦然？

我正在開發 WPF 應用程序並使用流閱讀器。

Answer 1

將圖像更改為字節數組的示例代碼

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

C# 圖像到字節數組和字節數組到圖像轉換器類

Answer 2

要將 Image 對象轉換為byte[]您可以執行以下操作：

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

Answer 3

從圖像路徑獲取字節數組的另一種方法是

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

Answer 4

這是我目前正在使用的。 我嘗試過的其他一些技術不是最佳的，因為它們改變了像素的位深度（24 位與 32 位）或忽略了圖像的分辨率 (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();

圖像到字節數組：

  /// <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();
     }
  }

字節數組到圖像：

  /// <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;
  }

編輯：要從 jpg 或 png 文件中獲取圖像，您應該使用 File.ReadAllBytes() 將文件讀入字節數組：

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

這避免了與位圖希望其源流保持打開相關的問題，以及一些建議的解決該問題的方法，這些解決方法導致源文件被保持鎖定。

Answer 5

試試這個：

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()方法將任何文件讀入字節數組。 要將字節數組寫入文件，只需使用File.WriteAllBytes()方法。

希望這會有所幫助。

您可以在此處找到更多信息和示例代碼。

Answer 7

您是否只想要像素或整個圖像（包括標題）作為字節數組？

對於像素： CopyPixels圖上使用CopyPixels方法。 類似的東西：

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 以在流中攜帶字節，則該方法將不會返回任何內容。 確保您引用 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

Answer 9

代碼：

using System.IO;

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

Answer 10

這是用於將任何類型的圖像（例如 PNG、JPG、JPEG）轉換為字節數組的代碼

   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

將圖像轉換為字節數組。代碼如下。

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

將字節數組轉換為圖像。代碼如下。代碼是處理圖像保存A Generic error occurred in GDI+中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

此代碼從 SQLSERVER 2012 中的表中檢索前 100 行，並將每行一張圖片保存為本地磁盤上的文件

 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();
               }

    }

請注意：具有NewFolder名稱的目錄應存在於 C:\\