


                                  - 1 -



       COMMAND

       ffffllllaaaaggggsssseeeetttt ---- sssseeeetttt iiiimmmmaaaaggggeeee ffffllllaaaaggggssss

       USAGE

       ffffllllaaaaggggsssseeeetttt ----iiiioooorrrrccccbbbbuuuuCCCCNNNNRRRRLLLL

       DESCRIPTION

       The header of an _E_c_h_o image contains some flags which
       indicate to the software functions certain properties of the
       image data.  Most EEEEcccchhhhoooo images are created by processes that
       explicitly and automatically assign the proper flag states
       reflecting the appropriate geometry and properties for the
       image.  Certain procedures may require these flags to be
       manually changed.

       ----iiii    Set the image type to inside-out.

       ----oooo    Set the image type to outside-out.

       ----rrrr    Set the image type to rectangular.

       ----cccc    Set the image type to cylindrical.

       ----bbbb    If image is rectangular, interpret in the special
             bilateral mode.

       ----uuuu    If image is rectangular, interpret in the normal
             unilateral mode.

       ----RRRR    Set the geometry to a Right-Hand coordinate system.

       ----LLLL    Set the geometry to a Left-Hand coordinate system.

       ----CCCC    Set the image type to color.

       ----NNNN    Set the image type to no-color, range only.

       FFFFllllaaaaggggsssseeeetttt enables you to change the flag state reflecting the
       coordinate space assumed during various operations.  Such a
       need might arise, for example, if you develop a function
       which involves a transformation of image data from
       cylindrical to cartesian coordinates and you want to perform
       some operation on this data which requires explicit
       knowledge of the intended geometry.















                                  - 2 -



       CAVEATS

       FFFFllllaaaaggggsssseeeetttt does not change the image data in any way.  Only the
       attributes are changed.  Setting the flag on a cylindrical
       dataset will not convert it to a rectangular data set.
       However the display commands will project it into cartesian
       space, interpreting the radius values as Z values.

       You should double check, using the ssssttttaaaattttuuuussss command, the
       current value of llllggggiiiinnnnccccrrrr.  The value is usually 12272 for 512
       longitude cylindrical images.  Typical values for 512
       longitude cartesian images would be 417 for linear table
       scans and 781 for relief images transformed from cylindrical
       to cartesian space.

       Some digitizers produce images in a left-handed cylindrical
       coordinate system.  If your left thumb is extended to
       indicate the positive Y axis (usually upwards), your curved
       fingers will point in the direction of increasing longitude.

       Color digitizers will produce images with the color flag
       set.  This indicates that a companion color file exists.  If
       the color file is un-needed and deleted the flag can be
       cleared to prevent error messages.

       Setting the color flag can enable some special effects.  Any
       SGI type image file with the proper dimensions may be used
       to map color onto the range verticies.  Name the file the
       same as the range image file with the extention Give the
       command ffffllllaaaaggggsssseeeetttt ----CCCC to set the color flag.  The display
       commands will now use the color file.




























