minimum requirement:
the type of image is array2d
the type array2d is indicated by the local tag "!array2d"
array2d is a string of the following format:

width and height of the image in pixels, seperated by one or more spaces and/or newLines
followed by zero or more spaces and/or newLines and the imageBody

the imageBody is a list of the pixelValues surrounded by square brackets.
the pixelValues are integers seperated by one or more spaces and/or newLines
the ordering if from left to right and from top to bottom. eg.:
	+-----+
	|1 2 3|
	|4 5 6| --> "3 3 [1 2 3 4 5 6 7 8 9]"
	|7 8 9|
	+-----+
	
or:

3 
3[
1 
2  3 
  4 5 6 
7  8 
9
]

(can also be correctly read by Steca)

for best human readability array2d should be a multiline string and the pixelValues of one row of pixels are seperated by spaces, and the individual rows are seperated by newLines. eg:

8 8 [
1 3 1 0 3 0 1 2 
6 7 4 8 4 8 7 6 
3 6 9 2 3 1 9 6 
4 6 4 4 4 5 6 4 
6 3 6 5 4 9 3 3 
9 4 8 8 5 6 6 4 
8 4 5 2 3 5 6 11
0 0 0 0 0 0 0 0
]

written to a yaml file it looks somethong like: 

measurement:
    scan:
    -   scan_parameters: {}
        time: 300.0
        monitor: 1565881
        sum: 737171
        image: !array2d |-
            8 8 [
            1 3 1 0 3 0 1 2 
            6 7 4 8 4 8 7 6 
            3 6 9 2 3 1 9 6 
            4 6 4 4 4 5 6 4 
            6 3 6 5 4 9 3 3 
            9 4 8 8 5 6 6 4 
            8 4 5 2 3 5 6 11 
            0 0 0 0 0 0 0 0
            ]