What exactly does changing the depthiroffsetx parameter used by the openni driver do? In fuerte, this parameter (or something similar) appeared to select the bbox of the published 640x480 images by shifting the entire image left|right (and offsety shifted up|down). In indigo, however, the offsetx and offsety do not appear to affect the published image... only the published point cloud.

1) What units are these parameters in? (maybe pixels, but the change in the point cloud seems too large for pixels)

2) What image topics are they used to align? (maybe /camera/rgb/imagerectcolor + /camera/depth/imagerectraw)

3) Where do I find the source code that uses them?