MediaWiki:Exif-subjectarea/qqq

Exif is a format for storing metadata in image files. See this Wikipedia article and the example at the bottom of. The tags are explained briefly and in further detail.

This exif property contains the position of the main subject. The first two numbers is the position of the subject in the picture in pixels from the upper left corner. If a third number is specified, it is a circle centred at the first two numbers. If four numbers are specified, the first two are coordinates of the centre of the subject as before, the third is the width of the rectangle, and the fourth is the height of the rectangle. It is rare for a photo to use this tag.