</a></dt>
<dd><p>Returns the overall step for a pair (raster_pos, raster_step).
When looking at a single raster position, steps are counted as 0,1,2,3,.. etc.
Sometimes it is necessary to convert this step into the actual image step
of the whole raster.</p>
<p>Example: three raster positions: 0, 1, 2 with three exposures each</p>
<p>raster image step: 0, 1, 2, 3, 4, 5, 6, 7, 8
raster position:   0, 1, 2, 0, 1, 2, 0, 1, 2
raster step:       0, 0, 0, 1, 1, 1, 2, 2, 2</p>
<dl class="field-list simple">
<dt cla