Unsupported value for 'PhotometricInterpretation'

[ilia71]

Hi,

I currently downloaded Dcmtk 3.6.0 and trying to run this simple piece of code:

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int main() {

	DcmRLEDecoderRegistration::registerCodecs();
	DcmFileFormat fileformat;
        if (fileformat.loadFile("test.dcm").good()) {
		DcmDataset *dataset = fileformat.getDataset();
		OFCondition a = dataset->chooseRepresentation(EXS_LittleEndianExplicit, NULL);
      if (dataset->canWriteXfer(EXS_LittleEndianExplicit)) {
			  fileformat.saveFile("test.dcm", EXS_LittleEndianExplicit);
           DicomImage bmImg(dataset, EXS_LittleEndianExplicit);
			  int b = bmImg.writeBMP("testBmp.bmp");// Trying to get the bitmap image from the first frame
		}
	}
	DcmRLEDecoderRegistration::cleanup();
    return 1;
}

After the line: DicomImage bmImg(dataset, EXS_LittleEndianExplicit); i get the message E: unsupported value for 'PhotometricInterpretation' (PALETTE COLOR)
And the following line is not properly executed (i.e. the bitmap image wasn't created).

any hint?

[J. Riesmeier]

You have to register support for color images by adding the following line to your application (and by linking the dcmimage library to it):

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#include "dcmtk/dcmimage/diregist.h"     /* include to support color images */

[ilia71]

Perfect!

Thank you.

[ilia71]

Few more questions.
1) I noticed that when i execute

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fileformat.saveFile("test.dcm", EXS_LittleEndianExplicit);

, the image in the new DICOM file is Gray Scale rather then RGB as it used to be. How can i save it in RGB format?
2) How can i access DICOM's data fields like 'Frame Time Vector' , 'Heart Rate', etc. ?

Thank you

[J. Riesmeier]

Re. 1) I have no idea, but is your DICOM input image RLE-compressed? Maybe, something is wrong with the encoding...

Re. 2) Use findAndGet...() on the DICOM dataset. See Example in the documentation.

[ilia71]

I have also tried to decode JPEG-LS image of 1.2.840.10008.1.2.4.70 transfer syntax UID by performing:

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DJLSDecoderRegistration::registerCodecs(); // register JPEG-LS codecs

But it went unsuccessfully, i.e. the condition:

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if (dataset->canWriteXfer(EXS_LittleEndianExplicit))

returns false.
Am i doing something wrong?

[J. Riesmeier]

What does the logger show? You could also try the respective command line tool, i.e. dcmdjpls/dcml2pnm or dcmdrle/dcm2pnm (probably with debug mode enabled).

[ilia71]

i tried

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DJDecoderRegistration::registerCodecs();

and it worked just fine!

[J. Riesmeier]

Then the image is not JPEG-LS compressed but with one of the conventional JPEG compression schemes. The transfer syntax UID "1.2.840.10008.1.2.4.70" also refers to JPEG Lossless and not to JPEG-LS.

[ilia71]

Yes, it was my mistake.

[ilia71]

Hi,

I have a small question regarding data extraction from the dataset (of a type DcmDataSet*).
In my code i was using the following two lines:

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dataSet->findAndGetUint32(DCM_RegionLocationMinX0, oMetaInfo.RegMinX0);
dataSet->findAndGetUint16(DCM_SamplesPerPixel, oMetaInfo.SamplesPerPixel);

While the second line worked just fine(placed the correct value inside SamplesPerPixel, which is a member
of a type Uint16 inside a struct called oMetaInfo), the first line didn't(placed zero inside RegMinX0 as if Uint32
is not the right VR for the tag key DCM_SamplesPerPixel although it is!).

I hope my question was clear,
Thank you

[Michael Onken]

Hi,

i would be surprised if this is really a bug in DCMTK. Please check that the tag exists in your dataset, that your target variable is of type Uint32, and also maybe check the return value (OFCondition). If you have time, use the debugger to see where the error occurs.

Thank you,
Michael

[J. Riesmeier]

I guess the returned status is "tag not found": RegionLocationMinX0 is usually contained in the SequenceOfUltrasoundRegions and not part of the top-level dataset, so you either have to retrieve the sequence element first or set the "searchIntoSub" parameter of your findAndGetUint32() call to OFTrue.

[ilia71]

Worked great! thank you

[ilia71]

Hi,

Just one more thing.
After i decompressed the data set using:

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dataSet->chooseRepresentation(EXS_LittleEndianExplicit, NULL);

how can i extract a single frame (without initializing an instance of DicomImag, which is not so efficient considering the fact i need only the first frame
while the entire Image might be quite big)?

Thank you