Re: JPEG Lossless decompression

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
.

Relevant Pages

  • Re: JPEG Lossless decompression
    ... I have the viewer to the point were I support all common ... 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: ... 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 using the underlying OFFIS C++ classes, _AND_ JPEG 2000. ...
    (comp.protocols.dicom)
  • Re: OT: Early Fall
    ... Since you are not processing the jpg and then saving the file, the compression and decompression will not introduce noise into the photo. ... TIFF pictures store a single raster image at any color depth. ... Not all TIFF files are compatible with all programs that support the baseline TIFF standard. ... JPEG pictures store a single raster image in 24-bit color. ...
    (rec.boats)
  • Re: 4mp doubled = 16mp!?
    ... quality JPEG settings did indeed make more detailed images ... my 2 Kodaks have no ability whatsoever to alter compression, ... large prints from as large an image in mega pixels as you can ...
    (rec.photo.digital)
  • Re: JPG compression - yet another question !
    ... Photoline can work equally well. ... That's not the nature of the JPEG spec as I ... It's lossless in the same way that you can unzip a compressed ZIP or RAR file ... compression types against each other and instantly ...
    (rec.photo.digital)
  • Re: JPG compression - yet another question !
    ... know into Photoline work-flow methods and tool-names. ... That's not the nature of the JPEG spec as I ... JPEG compression. ...
    (rec.photo.digital)