Using SelectSX

SelectSX can be used to create a new Stradx data file containing selected B-scans from an existing Stradx data file. One reason you might want to use this facility is if you've recorded a very dense 3D data set and wish to thin it down a little. Equally, it can be useful for removing trailing B-scans from a data set if the probe lost contact with the skin surface before recording was stopped.

SelectSX was written by Graham Treece. It is used as follows.


 Required input files :
   {filename}.sx  - data information file as output from Stradx.
   {filename}.sxi - data file as output from Stradx.

 Input parameters :                                            (default)
   -{I|i} {filename}    input file name (no extension)           'input'
   -{O|o} {filename}    output file name (no extension)         'output'
   -{R|r} {range}       range of B-scans, e.g. '2,10-30,45-'      (none)
   -{S|s} {step}        use every {step} B-scans                       1
   -{H|h|?}             display this help screen                      no

 Output files :                                                         
   {filename}.sx  - data information file as input to Stradx.
   {filename}.sxi - data file as input to Stradx.

Using StackSX

Note that voxel data sets can now be generated directly from Stradx, using the Voxel Controls window. This window is based on the Reslice facility, and hence it can cope with image registration, multiple scan sequences, masking of data to surfaces, RF data and much more. The StackSX utility will only work correctly for simple Stradx data sets, and will not be undergoing any further development. It is included in order to provide an off-line utility should that be required, but may not be included in future releases.

Stradx does not use voxel format data in any of its tools. This means that using Stradx you can visualise the data or analyse volumes immediately after (or even during) the recording of the 3D data. There is no need to wait for a voxel array to be constructed.

You only need to use StackSX if you want to voxelize a Stradx data set in order to visualize it using a standard viewing package, for example the 3DViewnix visualisation system (available from the University of Pensylvania).

StackSX outputs the voxel array in standard Stradx data format, so you can, if you wish, load the reconstructed data back into Stradx: you will notice that all the B-scans are now parallel and uniformly spaced. Since the output `.sxi' data file is a simple block of bytes (row-by-row, then slice-by-slice), it can also be loaded into other standard visualisation packages. The dimensions of the voxel array can be gleaned from the output '.sx' file.

StackSX was written by Graham Treece. It is used as follows.


 Required input files :
   {filename}.sx  - data information file as output from Stradx.
   {filename}.sxi - data file as output from Stradx.
        *    .sxc - calibration file referenced in {filename}.sx.

 Input parameters :                                            (default)
   -{I|i} {filename}    input file name (no extension)           'input'
   -{O|o} {filename}    output file name (no extension)         'output'
   -{R|r} {resolution}  interpolation resolution (pixels)            1.0
   -{P|p}               use pixel interpolation                       no
   -{A|a} {distance}    maximum interpolation distance (pixels)     auto
   -{H|h|?}             display this help screen                      no

 Output files :                                                         
   {filename}.sx  - data information file as input to Stradx.
   {filename}.sxi - data file as input to Stradx.
   {filename}.sxc - calibration file as input to Stradx.

 NOTE: The voxel array is constructed using a simple nearest neighbour
 algorithm: each voxel is set to the value of the nearest B-scan pixel.
 If pixel interpolation is switched on, then each voxel is set using
 bi-linear interpolation of the four nearest pixels on the closest
 B-scan. This option slows down the reconstruction a little, and is not
 available with colour Doppler data, since Stradx codes the colour
 information and linear interpolation of the code values would produce
 incorrect results. If no maximum interpolation radius is specified, it
 is chosen such that there are no empty voxels between the B-scans: thus
 in general only the file names need be specified. The orientation of
 the reconstructed voxel array is chosen to be close to the alignment of
 the input B-scans, and such that the size of the output is as small as 
 possible, given the resolution. The output '.sxi' data file is a simple
 block of bytes (row-by-row, then slice-by-slice), and can therefore be 
 loaded into other standard visualisation packages. The dimensions of the
 voxel array can be gleaned from the output '.sx' file.