[xml] Insert images to XML file

I would like to insert an images within an element the XML file, what is the best way to do this? Would you please suggest some good way to include an images to xml file?

Since XML is a text format and images are usually not (except some ancient and archaic formats) there is no really sensible way to do it. Looking at things like ODT or OOXML also shows you that they don't embed images directly into XML.

What you can do, however, is convert it to Base64 or similar and embed it into the XML.

XML's whitespace handling may further complicate things in such cases, though.

The most common way of doing this is to include the binary as base-64 in an element. However, this is a workaround, and adds a bit of volume to the file.

For example, this is the bytes 00 to 09 (note we needed 16 bytes to encode 10 bytes worth of data):

<xml><image>AAECAwQFBgcICQ==</image></xml>

how you do this encoding varies per architecture. For example, with .NET you might use Convert.ToBase64String, or XmlWriter.WriteBase64.

I always convert the byte data to a Base64 encoding and then insert the image.

This is also the way that Word does it, for it's XML files (not that Word is a good example on how to work with XML :P).

XML is not a format for storing images, neither binary data. I think it all depends on how you want to use those images. If you are in a web application and would want to read them from there and display them, I would store the URLs. If you need to send them to another web endpoint, I would serialize them, rather than persisting manually in XML. Please explain what is the scenario.

Here's some code taken from Kirk Evans Blog that demonstrates how to encode an image in C#;

//Load the picture from a file
Image picture = Image.FromFile(@"c:\temp\test.gif");

//Create an in-memory stream to hold the picture's bytes
System.IO.MemoryStream pictureAsStream = new System.IO.MemoryStream();
picture.Save(pictureAsStream, System.Drawing.Imaging.ImageFormat.Gif);

//Rewind the stream back to the beginning
pictureAsStream.Position = 0;
//Get the stream as an array of bytes
byte[] pictureAsBytes = pictureAsStream.ToArray();

//Create an XmlTextWriter to write the XML somewhere... here, I just chose
//to stream out to the Console output stream
System.Xml.XmlTextWriter writer = new System.Xml.XmlTextWriter(Console.Out);

//Write the root element of the XML document and the base64 encoded data
writer.WriteStartElement("w", "binData",
                         "http://schemas.microsoft.com/office/word/2003/wordml");

writer.WriteBase64(pictureAsBytes, 0, pictureAsBytes.Length);

writer.WriteEndElement();
writer.Flush();