3 DAOGREY – Display an image

DAOPHOT does not directly use an image display, instead it produces image files of intermediate results which can be displayed on any available display system. It is often desirable to indicate the positions of stars on top of the displayed image. To achieve this some special routines have been created.

DAOGREY is the first of these routines and this will display the image data on a suitable device. It is executed by typing:

  % daogrey

The following parameters are requested:

IN – NDF containing input image
The name of the file containing the image data.
XSTART – first index of subarray
XEND – second index of subarray
YSTART – first index of subarray
YEND – second index of subarray

These specify the limits in pixel coordinates of the area of the data array to be plotted.

The choice of values allows subsections of the data to be viewed.

LOW – lowest data value to plot
HIGH – highest data value to plot

These specify the data values corresponding to black and white on the display. The grey levels in between are set automatically.

DEVICE – Display device

The name of the display device to be used. The image is plotted in the centre of the display, best filling the display area.