[vtkusers] [Gdcm2] vtkGDCMImageReader for reading JPEG 2000 lossy compressed image data

[Mathieu Malaterre]

'lo JP, long time !

On Mon, Sep 15, 2008 at 6:59 PM, Jean-Pierre Roux
<jpr at creatis.insa-lyon.fr> wrote:
> Mathieu Malaterre wrote:
>>
>> Madhu,
>>
>> [CC'ing everybody to close the loop.]
>> TransferSyntax is 1.2.840.10008.1.2.4.91 [JPEG 2000 Image Compression]
>> NumberOfDimensions: 3
>> Dimensions: (1024,200,200)
>> Origin: (0,0,0)
>> Spacing: (1,1,0)
>> DirectionCosines: (1,0,0,0,1,0)
>> Rescale Intercept/Slope: (0,1)
>> SamplesPerPixel    :1
>> BitsAllocated      :8
>> BitsStored         :8
>> HighBit            :7
>> PixelRepresentation:1
>> ScalarType found   :INT8
>> PhotometricInterpretation: MONOCHROME2
>> TransferSyntax: 1.2.840.10008.1.2.4.91
>> Orientation Label: AXIAL
>>
>>
>
> Hi, Mathieu!
>>
>>
>
> [...]
>
> I think reading 'extra large' Dicom images will be very soon a major
> challenge for any DICOM reader.
> I have a 'Enhanced CT' image whose size is 1024x1024x2000 ...

I perfectly understand that. First milestone remains full GDCM 1.x
replacement unfortunately, that's why I differed this feature request
for now. I have been thinking about it and I've been learning how they
do that in the IJG code. So this will be challenging but definitely
fun to code !

> On gdcm1.3 I thought about writting a 'frame by frame Reader'.
> It was OK for uncompresseed images, but I had no idea on how to proceed with
> JPEG, or J2K compressed images, so I gave up :-(
> Did you plan anything, on gdcm2 ?

In fact uncompressed image is the most difficult case, since you have
to do pointer arithmetic...
May I recommend you to switch to gdcm 2.x ;)
just for record Madhu send me this very large image, because there was
a bug (that I did not know of), so i decided to split his image:

 $ gdcmraw -i input.dcm -o myprefix --split-frags --pattern %03d.jp2
 $ gdcmimg -i myprefix000.jp2 -o output.dcm

And here you go, you have the first slice of the J2K compressed
multiframes available as a single DICOM file, not bad for a two line
shell script ?

  I have not implemented the more complex multiframes uncompressed
case, please fill in a bug report so that I do not forget about it,
thanks.

2cts
-- 
Mathieu