Logo Questions Linux Laravel Mysql Ubuntu Git Menu
 

How to convert image to byte array

Tags:

c#

wpf

People also ask

How do I turn an image into a byte?

Create a ByteArrayInputStream object by passing the byte array (that is to be converted) to its constructor. Read the image using the read() method of the ImageIO class (by passing the ByteArrayInputStream objects to it as a parameter). Finally, Write the image to using the write() method of the ImageIo class.

What is byte array format?

The ByteArray class allows you to read from and write to a binary stream of data, which is essentially an array of bytes. This class provides a way to access data at the most elemental level.

How do I convert a bitmap to a byte?

In addition, you can simply convert byte array to Bitmap . var bmp = new Bitmap(new MemoryStream(imgByte)); You can also get Bitmap from file Path directly.


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


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;
}

Another way to get Byte array from image path is

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

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.


try this:

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;
}