[vtk-developers] Re: vtkStringArray and vtkImageReader

[dean.inglis at camris.ca]

Hi David,

I run into file name schemes of the type (sorted here)

I0012345.M01
I0012345.M02
I0012345.M03
I0012346.M01
I0012346.M02

or in general:

*< numeric_1 >.*< numeric_2 >

wherein standard alphabetical sorting does not work,
and sorting is required on two passes:
first on numeric_1 and then on numeric_2. 

With regard to item 2), would it be sensible to
implement the API for vtkSortSeriesFileNames using a
callback mechanism:  that is either vtkSortSeriesFileNames 
(or vtkImageReader) could broadcast a vtkCommand::SortFileNames 
event that users could add a callback to that would permit
custom sorting.  Use scenario:

vtkStringArray array

vtkSortSeriesFileNames sorter
sorter AddObserver vtkCommand::SortFileNames mysortcallback 
sorter SetFileNameArray array
sorter Sort

vtkImageReader reader
reader SetFileNameArray sorter GetSortedFileNameArray

Just a thought, and thanks for working on this.  I for one
welcome the additions!  The other thing that would be useful is if 
vtkImageReader could read a series of single files having variable 
length headers. 

Dean

>My solution is to write two classes and modify vtkImageReader to accept 
>a list of files:
>1) write a vtkGlob class that handles wildcards and produces a 
>vtkStringArray of files, implemented with Utilities/kwsys/Glob.
>2) write a vtkSortSeriesFileNames class that will sort a vtkStringArray 
>of file names taken from vtkGlob or from a file browser
>3) add a SetFileNames() method to vtkImageReader2 so that it can take a 
>vtkStringArray containing file names