Web Worker unable to load image with JP2 Header file.

[Neuroforge]

When loading the Web Worker the following image throws an error.

https://sourceforge.net/p/gdcm/gdcmdata/ci/master/tree/ELSCINT1_JP2vsJ2K.dcm?format=raw

There are a number of images of this type which throws the error.

wado-image-loader-codecs.min.js:108163 Uncaught Error: JPX Error: Unsupported COD options (selectiveArithmeticCodingBypass)

The loaded image does not have a getCanvas() method attached to it.

[malaterre]

Just for reference, the file ELSCINT1_JP2vsJ2K.dcm is a well known case where the private vendor sent the full JP2 header instead of a raw JPEG 2000 codestream.

This is clearly unacceptable from a strict point of view:

• http://dicom.nema.org/medical/dicom/current/output/chtml/part05/sect_8.2.4.html#para_9146fe8f-7760-48f7-8a52-9c1dbf1ca927

Note in particular that the JP2 file header is not sent in the JPEG 2000 bit stream that is encapsulated in DICOM.

The question left open is of course: what is the course of action for cornerstone: should support or not ?

[Neuroforge]

Is it possible to strip this header and 'normalise' the image in javascript before trying to load it in cornerstone?

[malaterre]

AFAIK the codec used by cornerstone for JPEG2000 is OpenJPEG. Since the above JP2 is well handled by OpenJPEG, I would suggest to update the support for JPEG2000 to handle both J2K and JP2 and be done with this (this is what GDCM does BTW).

OpenJPEG has always had a poor support for parsing operation (non-decoding ones). For instance:

• Need public function to tell kernel type used (5x3 vs 9x7) uclouvain/openjpeg#3

so I believe this is a no-go solution (unless someone wants to implement a simple JP2 parser). For reference:

• https://github.com/malaterre/saj/blob/master/simpleparser.c#L198

[malaterre]

@chafey You mentionned in some other bug report that focus should be on legal image only. This one has a JP2 header which has been prohibited since day 1 in the DICOM standard.