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Image with sky grid overlaid

To produce a high-quality black-and-white figure of a source with a coordinate grid overlaid, use the following recipe:

1.
Open an SAOimage window, display an image, click on the color/invert button, and adjust the colors to get a black-and-white image.

2.
Set the following display parameters:

display.xcenter=0.55

display.ycenter=0.51

3.
Display a 430$\times$430 pixel section of the image (blocked or unblocked). (This allows room in the SAOimage display for coordinate labels outside of the figure. Labels can also be inside, in which case step 2 is unnecessary and the full 512$\times$512 pixels can be displayed.)

display ``rp110590n00.qp[bl=15][249:679,409:839]'' 1

4.
Run wlpars, which will invoke eparam on one of the wcslab parameter files, and change ``major_g'' to no and ``title'' to blank (hit space then return). (The title option here may be used, but it requires that a smaller region be displayed. A different labeling option is used in step 7.) Packages ``images'' and ``tv'' must be loaded to run wlpars and wcslab.

5.
Set the wcslab parameter ``device'' to imdB (for a black overlay). (Other colors are available, see below.)

wcslab.device=``imdB''

6.
Run wcslab (overlays a world coordiante system).

wcslab ``rp110590n00.qp[bl=15][249:670,409:839]'' 1

7.
Make a hardcopy (from outside IRAF) using facilities available on your machine, e.g., screendump.

AT SAO: xprint -saoskip -nobdrs -portrait -P lp -label ``Fig. 986A'' -font 24


next up previous contents
Next: *tvimcontour* - Overlay contours Up: Celestial Coordinates from Image Previous: *wcscoord* all
rsdc@cfa.harvard.edu
1998-06-10