Here is an example of a diagram that needs to be redrawn:
- Not all text would have been legible.
- The diagram would have included information the audience doesn't need.
- The diagram might have looked pixelated.
The actual colors (see below) are the result of the different transparency value assigned to each country and the slide background. I added the color legend and the result of the text on Keynote. In fact I animated the color legend to layer the information presented on the slide.
As I mentioned the finished map does not come directly from the vector graphics program. Here is the raw version. Note how the light green turns dark and viceversa in the finished result. This is a result of the dark blue background. That color is also playing the role of the ocean. The new diagram is not 100% the same as the original one. It zooms-in more than the original. In the latter the whole black sea and the southern part of Italy are shown, but do I needed them? No.
|Slide's raw version right out of Inkscape|
Should all diagrams be redrawn? No. Some diagrams might be just fine as they are. Also there is the practical issue of time. This takes time on preparing a talk. In case of doubt, use the time to rehearse, not to redraw. And if you think you might need the diagram as a building block of for research presentation, redraw it after the talk and use it on the next one. Remember that a raw version could be reuse in a written document.