[Insight-users] No DICOM magic number found, but file appears to be DICOM...

[Wei-Lin Bee]

Dear Luis,

My multiphoton microscope image pixel type is 16 bit, and my goal is to do image
registration and segmentation with ITK to get 3D image.

My first step should be registration, I tested my image file with
ImageRegistration2.exe (cause pixeltype in this example is defined as unsighed
short) in ITK source directly to see what the error messages I would have so
that I can get the right direction to go.

My error message is "No DICOM magic number found, but file appears to be
DICOM.Proceeding without caution." After looking for answer from internet, I
got your answer as follows:

============================================================
Luis Ibanez luis . ibanez at kitware . com 
Wed, 01 Oct 2003 16:40:17 -0400 

Hi Thimmaiah,
Good news and bad news.

First, here are some the facts:
1) There are two DICOM readers in ITK
    - DICOMImageIO
    - DICOMImageIO2
2) DICOMImageIO reads your images without complaints.
    This is the default reader registered in the IO
    factories and therefore is the one used in the
    demo application "ImageViewer".
3) DICOMImageIO2 does a more formal testing and
    prints the message:
   > No DICOM magic number found, but file appears to be DICOM.
   > Proceeding without caution.
    but still reads the image.
    This is the reader used in "ApplicationModel"
    and it is able to read the 3 slices and
    create a volume with them.
4) VolView reads your DICOM images without
    complaints, and display them correctly.
5) MRIConvert reject your images because they
    are missing the Preamble.
    "Preamble missing. Unable to read file"
---------------------------------------
So,

The good news is:
   You can read your DICOM slices IFF you use
   the DICOMImageIO instead of DICOMImageIO2.

   So, when you configure the ImageSeriesReader,
   please provide a DICOMImageIO, instead of a
   DICOMImageIO2 object.

The bad news is:

   your DICOM files are suspicious (let's say
   sloppy), and you may want to complaint with
   your image provider because they don't fully
   satisfy the DICOM standard.
Regards,
   Luis

=================================================================

I've learned from ItkSoftwareGuide,pp193-199 that itk::ImageFileReader and
itk::ImageFileWriter are independent of any particular file format, and
PixelType declaration plays an important role in format issue so I don't know
whether I have to do is make new itkXXXImageIOFactory.h itkXXXImageIO.h
itkXXXImageIO.cxx and itkXXXImageIOFactory.cxx.

I guess my question is not brand new one, please give me related reference
if you've already replied.


All the best,
Tiger

ps.my system is InsightToolkit-1.8.0, VC7.NET 2003.