It's actually a direct hex representation of the binary .png image, not even base64 encoded. In other words, if you create a file called mypng.png where the first byte is 0x89, the second one is 0x50, and so on, ignoring the newlines in the text, you should be able to open and view the picture. (In this case it's a scribble).
As to how to convert it, well, it depends.
Just to give you a starting point, since you have Word, if you open the file in Word as a text file (so you can see the RTF code rather than the picture - you may have to set the "confirm conversions at open" Word Option to do that), select the data bytes, and run the following code (you will need to change the file/path name), you should be able to open the output .png
Sub saveSelectionAsBinary() Const pngpath As String = "c:\a\mypng.png" Dim i As Long Dim s As String * 1 Dim t As String Kill pngpath Open pngpath For Binary As 1 t = Selection.Text i = 1 Do While i <= Len(t) If Mid(t, i, 1) = vbCr Then Debug.Print "cr" i = i + 1 Else s = Chr(Val("&H" & Mid(t, i, 2))) Put #1,, s i = i + 2 End If Loop Close #1 End Sub I suppose it is obvious that "pngblip" tells us that this is supposed to be a .png format picture, but there can be other types of picture in an RTF pict, and they are not necessarily encoded this way.