The WDEFROI function allows the user to select an arbitrarily shaped region-of-interest (ROI) from a displayed image via the mouse. The routine returns either a sub-image or a list of indices to the image displayed which defines this sub-image. If a data cube is passed the routine returns either a sub-image data cube or 2-dimensional list of indices. NOTE, WDEFROI is not SXT specific and thus will also work for ground base images.
Some example calls are:
IDL> list = wdefroi( data, zoom=8)
IDL> sub_image = wdefroi( data, zoom=8, /image)
IDL> list = wdefroi( data, zoom=zoom, /lc, time=time, sub=sub, /logscale)
where,
(A) PFI Example: An example of selecting a feature from a 64
64 pfi image:
Follow the instructions displayed on the widget.
IDL> nimage = wdefroi(data, /image, zoom=8)
(B) FFI Example An example of selecting a small feature from a 512x512 image:
Due to the fact that contouring a large image is a very slow
process do not attempt to contour a 512 512 image directly
but rather use the ``Box'' and ``select'' features to first isolate
the area of interest before using the ``contour'' feature. NOTE:
the ``contour'' feature can still be somewhat slow after isolating a
part of FFI. Follow the instructions displayed on the widget.
IDL> sub_img = wdefroi(img,/image) ;default zoom is 1
(C) PFI Data Cube Example: An example of selecting a feature from a cube aligned PFI data set
which has the dimensions of 65x65 by 40 images. The first line makes a buffer for
the normalized data. The second line puts the exposure normalized data into dat.
The last line uses the ``light curve'' option and passes the index information
for the image times.
IDL> dat = fltarr(65,65,40)
IDL> for i=0,39 do dat(0,0,i) = data(*,*,i)/gt_expdur(index(i))
IDL> sub_img = wdefroi(dat,zoom=7,/image,time=index,/lc)
The function starts the STEPPER routine to allow user to select image. Once the
user ``quits'' STEPPER the WDEFROI widget will appear. Select a
``box'' ROI and use the mouse make the selection (use the right mouse
button to finalize the selection). Use the light curve button to
display a time profile of the total intensity from the selected ROI.
Select ``Exit'' to finalize your selection. Then run STEPPER on the
newly made SUB-images.