Suggestion #1
The vertical origin could be placed at the top or at the bottom of the image.
Suggestion #2
The origin could be defined as an index of zero or one. Thus, the top left pixel could be [0,0] or [1,1] at the user's preference
Suggestion #3
Relative offsets could be displayed, if the used selects a custom datum (origin), e.g. -23 and +10 could mean 23 rows up and 10 columns right of a user-selected pixel used as a reference.
Suggestion #4
The x,y coordinates could be displayed as either :
- row, column
column, row