If you wanted to translate this text to Russian, and you were supplied with a jpeg file, you'd have to carefully rub out the English, then redraw the complicated background, before you could finally add the Russian text. That would take a huge amount of time. Alternatively, if you were provided with a layered file, that puts text on one layer and background on another, it would be very quick and easy to produce the translation. Think, therefore, about how you go about the process of handing things off for localization.

Of course, an even better approach would be to use CSS positioning for the text. That would make it searchable and selectable. Try to avoid using readable pixellation when you can.