Generating a computer executable chart visualization by annotating a static image of said visualization

A method of generating a computer executable chart visualization from a static image of the chart visualization comprises: providing 304 the static image of the chart visualization; providing a set of pre-defined chart elements; identifying 306 one or more portions of the static image as corresponding to one or more respective pre-defined chart elements; determining 310 a mapping between the portions of the static image and the respective pre-defined chart elements; determining 312 visual properties of each of the portions of the static image; and generating 314 a declarative description of the chart visualization by setting the visual properties for each of the respective pre-defined chart elements. Image recognition may be used to locate visual borders of chart elements, and user input 308 may be provided for confirmation of accuracy and completeness of the identification. The method may render (504 in Figure 5) the declarative description to create an interactive visualization corresponding in appearance to the static image.