-------------------------------------------
var,funct (left-click): toggle view editable/im2
  set drawsecondflag 1
  redraw
  keyboard equiv Linux:
    keyboard equiv: <Alt-'>
    keyboard equiv: <Alt-Shift-C>      [b/c cmd-c reserved]
    keyboard equiv: <Alt-0>
  keyboard equiv Mac:
    keyboard equiv: <Cmd-'>
    keyboard equiv: <Cmd-Shift-C>      [b/c cmd-c reserved]
    keyboard equiv: <Cmd-0>
-------------------------------------------
funct (middle-click): swap contents editable/im2
  swap_imim2
-------------------------------------------
funct (shift-middle-click): copy im2 edits to editable
  im2wmedits_to_im
-------------------------------------------
funct (shift-left-click): copy contrast-adj'd to editable
  visible_to_im
-------------------------------------------


Detailed Description COMPARE button

A default left-click of the COMPARE button blinks
back and forth between first and second image set
(sunken button with 2nd image).  First, must READ
second imageset (re-read OK) (or use function:
read_second_images <cordir/mgzfile>).

Any image editing actions (middle/right clicks,
flip, smooth) are applied only to first (command
line) image set, regardless of which image set is
visible.  This can be helpful when the second
image is an "orig" image with better contrast and
context than the already-truncated white matter.

-------------------------------------------
Alt funct (middle-click): swap contents editable/im2
  swap_imim2
-------------------------------------------

An alternate middle-click of the COMPARE button
swaps the CONTENTS of the editable and im2
buffers.  This makes it possible to save out the
contents of the im2 buffer.  There is a warning
whenever this alternate function is called.  If
the editable buffer has been edited, there is a
second warning to confirm this is really what you
want to do.

-------------------------------------------
Alt2 funct (shift-middle-click): copy im2 edits to editable
  im2wmedits_to_im
-------------------------------------------

A second alternate shift-middle-click of the
COMPARE button applies edits from im2 to the
current editable buffer.  "Edits" are defined as
pixels that have the value 255 (edited to white)
or 1 (edited to black).

This can be used when in the course of a manual
reconstruction, if after already having edited a
white matter (wm) data set, you want to go back
and make additional local hand-normalization
steps (e.g., using spherical Gaussian: "sph" tick
in F3 panel), without losing the edits made so
far.  The procedure is:

  (0) already did many edits on wm.mgz
  (1) copy prev edited wm.mgz to new name
  (2) hand normalize, remake wm.mgz, load new one
  (3) load wm-old.mgz into "im2:" w/"R"
  (4) shift-middle-COMPARE
  (5) SAVE IMGS

-------------------------------------------
Alt3 funct (shift-left-click): cp contr-adj'd to editable
  visible_to_im
-------------------------------------------

A third alternate shift-middle-click of the
COMPARE button copies the contrast-adjusted
visible pixel values (N.B.: currently in the
editable buffer) to the editable buffer,
overwriting its current contents.

N.B.: the contrast-adjusted image is typically
the result of a non-linear (e.g., sigmoid)
function.

To avoid applying the contrast adjustments
recursively, $linearflag is set to 1 (see
interface button on lower right of large F4
interface panel).

This can be used, for example, to save a
contrast-reversed image (negative value for
"contr:").

N.B.: SAVE IMGS will overwrite the initial
dataset, so to save the contrast-adjusted images 
to a new file, enter a name in the upper right
"im:" entry and click "W".

To undo, alt/cmd-z in image window (or tools
window).
