[daip] Image overrlays

[Eric Greisen]

Jessica Rosenberg writes:

 > I had a question about making a plot that contains a greyscale image 
 > overlaid with my radio contours. The issue is that the spatial 
 > resolution of my optical image (for greyscale plotting) is much higher 
 > than the spatial resolution of my moment map. As far as I can tell, to 
 > get GREYS or any of the other plotting programs to overlay the images 
 > properly they have to have the same spatial scale. Is this true? If so, 
 > is there any way to re-pixelate my moment map? I really don't want to 
 > smooth the optical image, but I can't seem to find any way within AIPS 
 > to re-pixelate the moment map. If that is the case, I am going to have 
 > to re-image the field (I actually tried to do this but RASHIFT and 
 > DECSHIFT did not shift the field center so I am at a bit of a loss for 
 > how I would even manage this with re-imaging without having to make the 
 > image size prohibitively large). Is there a way to easily change the 
 > pixels scale of the moment map or the imaged cube? Is there some easier 
 > way to make this plot?

Use OHGEO to convert your moment map to the geometry of the optical
image.  (OHGEO handles blanked pixels better than HGEOM, the other
choice.)

Eric Greisen