Visualisation

Executables(SUN,solaris 2.5) of the tools described below are stored in the tools directory. The examples below assume the current directory is $lip_tracking/examples/, and $lip_tracking/tools has been added to the path environment variable.

1. Single frame using xgf

   Single frame tracking result can be visualised by xgf. It is a CVSSP home-grown tool that displays various types of geometric feature overlaid on a grey-scale image. A typical command line looks like this:

     xgf -R input_gf -b input_pgm

   For example, to view results for lc_04_spl/20.gf, then replace

     input_gf  -> ../results/LC/lc_04_spl/20.gf            
     input_pgm -> $database/LC/lc_04_v/20.pgm             

   Find the foreground menu, choose "Control" to view the control points standing along the outer lip contour. You can also choose "Segment 2", "Segment 3", ... to view how each Spline knot is connected to form the continuous points of the outer lip contour.

2. Single frame using a viewer
   

   Two utility programs, joinSpans and gf2pgmovl, can draw a lip contour in the original .pgm to produce an overlay .ovl.pgm file. Below is an example that generates an overlay file on `bp_01_v/1.pgm':

   • Join the segments of the spline to get the full contour

     cd overlays
     joinSpans < input_gf > tmp.gf
     

   • Draw the full contour in the original image

     gf2pgmovl -i input_pgm -g tmp.gf -o output_ovl.pgm
     cd ..

   Where `input_gf' is `../../results/BP/bp_01_spl/1.gf', `input_pgm' is $database/BP/bp_01_v/1.pgm' and `output_ovl.pgm' is `bp_01.1.ovl.pgm'

   Many viewer, eg xv, can display a .pgm file and convert it into other formats, eg. `.gif'.

3. Sequence using xv
   

   xv can display an image sequence. A .csh script render generates overlay files for all frames. After generating all overlay files of a sequence, you can view the full tracking results by:

    xv -wait 0 ?.ovl.pgm ??.ovl.pgm ???.ovl.pgm

4. Fast sequence using MPEG viewer
   

   The ovl.pgm sequence set of files can be converted into an MPEG file. Many packages available on the web can do this convertion, eg. ImageMagic.