*tvimcontour* - Overlay contours and/or source positions on the display

This task is a convenient amalgamation of xdisplay and imcontour which overlays contours and, if requested, source positions in sky coordinates onto the SAOimage display. As with imcontour the contouring works best on a smoothed image.

input file: rp90_ab_smo.imh²

 
  xp> xplot
  xp> tvimcontour
  IRAF image file:  rp90_ab_smo
  Grid type (sky/pix):  sky
  Contour units (pixel/peak/sigma): peak
  Contour levels:  log 5 100 5
  xp>

A convenient method for overlaying source positions on an image where you are not interested in the contours and/or an unsmoothed image is as follows:

  xp> tvimcontour src_lis=xdata$rp110590_src.tab
  IRAF image file:  xdata$rp110590_im1
  Grid type (sky/pix):  sky
  Contour units (pixel/peak/sigma): peak
  Contour levels:  log 100 100 1              # single contour at the peak.

imcontour (See also Smoothing and Contouring) can be used to overlay contours on an existing display with proper setting of the parameters: scale_device and graph_device and perim. Type help imcontour for more information.