dcmj2pnm problem with STDOUT

[hollebolle]

Hi everybody,

I am trying to develop a WADO-server, where dcmj2pnm converts a DICOM-file to JPG with

Code: Select all

dcmj2pnm +oj +Jq 90 +Wi 1 C:\dicom\test.dcm

So, I am not creating a file, I am using the STDOUT for my Outputstream in the webserver-software with content-type: image/jpeg.

The generated jpg in my Browser looks like:

instead of


Has anybody an idea what this could be? Is dcmj2pnm working correctly with STDOUT?

Thanks in advance and kind regards.

[Jörg Riesmeier]

In your case, the output is binary data (JPEG) and you seem to use Windows. I'm not sure whether Windows really supports binary data on stdout ... but this is just a guess.

Using a temporary file should always work.

[hollebolle]

Hi Jörg,

yes, that is possible. I'm working on windows. With a temporary file it's working fine. But that would have been too easy .

[Jörg Riesmeier]

It seems that Windows always opens the standard output in text mode. Maybe, something like the following works in order to overcome this:

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freopen(NULL, "wb", stdout);

However, I haven't tested it. Searching for this issue on the Internet might also help ...

[gurbuz]

You can see from Joerg's comments in dcm2pnm that stdout has not been verified for Windows:

Revision 1.50 2001/11/09 16:35:20 joergr
...
Added support for the direct output of the converted PNM/PGM/BMP image to the 'stdout' stream (not yet tested under Windows).

Try this fix. It worked for us.

Code: Select all

#ifdef WIN32
setmode(fileno(stdout), O_BINARY);
#endif

[Jörg Riesmeier]

Thank you for the follow-up. We will add this code line to the prepareCmdLineArgs() function for Windows systems.