How to convert image to byte array

Question

Can anybody suggest how I can convert an image to a byte array and vice versa?

I\'m developing a WPF application and using a stream reader.

Answer 1

Sample code to change an image into a byte array

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

Here's what I'm currently using. Some of the other techniques I've tried have been non-optimal because they changed the bit depth of the pixels (24-bit vs. 32-bit) or ignored the image's resolution (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();

Image to byte array:

  /// <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();
     }
  }

Byte array to Image:

  /// <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;
  }

Edit: To get the Image from a jpg or png file you should read the file into a byte array using File.ReadAllBytes():

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

This avoids problems related to Bitmap wanting its source stream to be kept open, and some suggested workarounds to that problem that result in the source file being kept locked.

Answer 3

Another way to get Byte array from image path is

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

Answer 4

Do you only want the pixels or the whole image (including headers) as an byte array?

For pixels: Use the CopyPixels method on Bitmap. Something like:

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 5

This is Code for converting the image of any type(for example PNG, JPG, JPEG) to byte array

   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 6

For Converting an Image object to byte[] you can do as follows:

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