Hiding xy axis values in hover tooltips

İ am trying to getting data values from an image through hover.
But I want to get only data values not x,y axis values.
How can I hide xy axis values hover tooltips.,

At the moment the only way to achieve this is to explicitly define a bokeh HoverTool like described in the HoverTool section here: http://holoviews.org/user_guide/Plotting_with_Bokeh.html