Re: JPEG Lossless decompression

On Oct 24, 4:47 pm, Mathieu Malaterre <mathieu.malate...@xxxxxxxxx>
wrote:
On Oct 24, 9:40 pm, Chuck McCrobie <mccrobie2...@xxxxxxxxx> wrote:





CT2...@xxxxxxxxx wrote:
I'm currently working on my capstone project at school which is a
DICOM Viewer. I have the viewer to the point were I support all common
formats except compressed images, which is my next area of work.  I'm
want to support DICOM images with transfer syntax
1.2.840.1008.1.2.4.70, JPEG lossless non-hierarchical first-order
prediction.

However, I have just hit a wall with this. I have not been able to
find very many resources online as to how I need to decompress the
pixel data, whether it be the algorithm or a library of some kind.

I should point out that while my capstone project is for school on
requirement is that an outside source (usually a business) requests
it.  As such this viewer is going to be used internally at a local
business, which I'm not sure, but may cause some problems with
licensing on libraries. Any help you can provide me will be greatly
appreciated.

Also, I don't know if it makes a difference or not not but I am
creating this in C#.

Perform extensive Googling for JPEG LOSSLESS, ignoring all the newer
"lossless rotation of your picture links" - perhaps google groups is
better suited.

In the end, you'll find several libraries:

1) Stanford
2) Cornell
3) ijg
4) OFFIS wrapped ijg classes

Since these are in C or C++, you'll have to create a DLL, then create
the appropriate access functions in C# with static extern.

Or use swig to wrap the library interface.

I'll leave it to you to determine the best library / trade-off out of
the four libraries above.

answer: use ijg !





I do have in my possession a set of libraries, in C# with the
appropriate wrapping and build scripts for JPEG
compression/decompression routines for JPEG Baseline, JPEG lossless
non-hierarchical first-order predication (and the other JPEG
compressions) using the underlying OFFIS C++ classes, _AND_ JPEG 2000
(using OpenJPEG).

I also have in my possession a C# based image viewer that just so
happens is able to handle DICOM images, both compressed and otherwise,
including Find/Retrieve functionality.  The most important part is the
ability to specify the exact transfer syntax you are willing to receive
(and none other) and the ability to compare a reference image against a
newly transfered image in another transfer syntax, generating a
difference bit map.  (Sorry, I have to go, I would have edited that
sentence!)

It would have been much more interesting, to me, if you had done your
viewer in Java as an Applet...  Then you would have gotten most (all?)
of the JPEG compression for free in the JAVA Image I/O routines - see
Pixelmed.  But I digress...

Almost. AFAIK JBIG is not available (black/white jpeg compression).
Correct ? I do not even know a toolkit that handle them BTW.

2cts
-Mathieu- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -

Thanks for all the input guys, I've very new to the area of
compression/decompression. I've looked at the libraries you've pointed
at and so far they seem okay. I think may be if I tell you a little
more about my project you might be able to help me out more.

The only thing I need to do for this project is do handle .70 transfer
syntax. Really the decompression part of my viewer is more proof of
concept than an end goal. The real goal is for me to create a design
that will allow more compression types to be support later with little
to no design changes. However, I can't show that the design works
unless I have at least .70 transfer syntax supported.

I'm currently leaning more towards http://support.dcmtk.org/docs/mod_dcmjpeg.html
, http://sourceforge.net/projects/jpeg ,or
http://apps.sourceforge.net/mediawiki/gdcm/index.php?title=Main_Page

After checking out the ijg it seemed like they were saying they don't
support JPEG lossless because it is very rarely used. Am I wrong
about this?

Also with this project I figured I would have to take a C/C++ library
and wrap it in C# for use. Does this give you guys any more
information that would help you point me along?

Thanks for much for the help so far.
.

Relevant Pages

  • Re: JPEG Lossless decompression
    ... I have the viewer to the point were I support all common ... formats except compressed images, which is my next area of work.. ... compression/decompression routines for JPEG Baseline, ...
    (comp.protocols.dicom)
  • Re: JPEG Lossless decompression
    ... I have the viewer to the point were I support all common ... formats except compressed images, which is my next area of work. ... compression/decompression routines for JPEG Baseline, ...
    (comp.protocols.dicom)
  • Re: JPEG Lossless decompression
    ... I have the viewer to the point were I support all common ... formats except compressed images, which is my next area of work. ... compression/decompression routines for JPEG Baseline, ...
    (comp.protocols.dicom)
  • Re: JPEG Lossless decompression
    ... I have the viewer to the point were I support all common ... formats except compressed images, which is my next area of work. ... that will allow more compression types to be support later with little ...
    (comp.protocols.dicom)
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