[Insight-developers] RE: [Insight-users] MetaIO - problems reading a stack of PNG imag es

[Miller, James V (Research)]

FYI, I modified the PNG reader/writer a couple of weeks ago so that it can 
support "pixel size".  PNG has fields in the header to specify the size of a
pixel in
meters (or the size of a pixel with unknown units). So I have the PNG reader
configured
so that it reads and writes the spacing information in these fields.  Since
we do not keep track of units in ITK, I set the PNG reader/writer to read
and write the units as unknown (as opposed to meters).

'Course, these does help with the stack of PNG problem because there is not
a place in the PNG format for specifying the spacing BETWEEN slices.



> I really recommend converting your slices to raw and then using 
> MetaImage.  That way you can record and read-in slice 
> thickness, voxel 
> spacing, voxel type, etc.   PNG format does not support this type of 
> info and it is critical to medical image analysis - 
> MetaImage, Analyze, 
> Gipl, and others support such info.
>