Re: [Gdcm2] Writing JPEG-LS using gdcm

[Suares T. T. <ta...@bw...>]

Mathieu,

thanks a lot for this quick answer and advice. That was very helpful.
You were right. I just tried with a 8bits image and there is no difference.
I was trying with a 16bits image before. So the issue was related to image
bitness.

I know JAI does provide a reader and writer to handle JPEGLS (*
CLibJPEGImageReader*, *CLibJPEGImageWriter*), which are used in combination
with some generated  DLLs and additional jar-library (*clibwrapper_jiio.jar*).
The problem is, those  DLLs are generated and work with windows 32-bit JRE
only. So, windows 64bit machine may handle JPEGLS using 32-bit JRE, but
that is not possible with 64-bit JRE on Windows. And it looks like they is
no way build JAI source code using 64-bit JRE in order to generate windows
64-bit DLLs. That is why I am trying to switch to gdcm. Or do you think
they may be a way to handle JPEGLS on windows 64-bit machine with JAI using
64-bit JRE? Maybe I am missing something.

Any way thanks again for those details.

Regards,
Suares



On Thu, May 24, 2012 at 10:05 AM, Mathieu Malaterre <
mat...@gm...> wrote:

> Hi Suares,
>
> On Thu, May 24, 2012 at 3:39 PM, Suares Tamekue Tatuebu
> <ta...@bw...> wrote:
> > this is Suares from SPL Harvard and BWH Boston.
> >
> > I saw you were involved in most of gdcm related documents I found in
> > Internet. So I thought you might be the right person to address my
> question
> > to and was hoping would have time to answer.
>
> Well, the FAQ refers to the mailing list instead for this type of queries.
>
> > I am trying to de-identify Dicom image by changing the pixel data using
> java
> > (commonly called pixed de-identification). My concern is specialy
> related to
> > JPEG Lossless which is not supported by the JAI on 64-bit Systems. So, I
> was
> > thinking gdcm might be the right tool to solve the problem.
>
> I believe JAI+JPEGLS on 64bits system do work, they simply produce
> improper files.
>
> > Basically I am trying to get a WritableRaster from the original image in
> > order to modify a certain region. Then I will  use this to rebuild a
> > modified image.
> >
> > I know I can get the image via the reader. I mean something like this:
> >
> >                  ImageReader reader = new ImageReader();
> >
> >                  reader.SetFileName(originalFilename);
> >
> >                  reader.Read();
> >
> >                  Image image = reader.GetImage();
> >
> > So my question is: what is the best way to get a writableRaster for this
> > image object? The example ScanDirectory.java very hepfull sofar. I see
> the
> > writableRaster is accessed via a created bufferedImage. But it looks like
> > the original image is being modified somehow maybe through assigning the
> > Photometric Interpration or conversion of the image (bitmap) into Byte or
> > short array. The built buffered image actually appears darker than
> before.
>
> No the image buffer is carefully passed from C++ to Java. Not a single
> byte is being touched.
> My guess is that you are viewing an unsigned 16bits image directly as
> if it was 8bits. You may need to rescale the scalar range to please
> whatever rendering engine you are using.
> To convince yourself play with 8bits data.
>
> HTH
> --
> Mathieu
>