Using Oxyplot heatmaps are rendered successfully (PNG) for some data, but the x-axis labels have a padding issue.

I was assigned maintaining the code just recently, so I am new to Oxyplot. But I fail to find a means in the API to control how the axis labels are controlled in more detail.

Can anybody help me out here? I would like to decrease the number of labels, if at all possible.

Kindest regards from Germany,
Florian