Chart analysis method and system

The invention relates to an image analysis method for automatically extracting data from a bar chart. A processor receives a digital image of a bar chart comprising a plurality of o-bars. The processor provides a plurality of hypothesis charts respectively specifying a sequence of h-bars, a particular way of grouping the h-bars into categories, and an injective mapping from the o-bars to the h-bars. The processor compares the h-bars of the hypothesis charts with the o-bars of the bar chart in the image for assigning the o-bars to series and categories in accordance with the one of the hypothesis charts whose h-bars are most similar to the o-bars and for returning the series and the category assigned to said o-bars.