problems extracting images (a single image) from a dicom file

eantoranz · 06-17-2013, 11:35 AM

Hi!

I'm having problems extracting images from a dicom file (as a matter of fact it only has a single image).

When I try with medcon, I get this:

Code:

$ medcon -w -d  -v -o prueba -c png -f dicom.dcm
(X)MedCon-Message: Writing in little endian as default
(X)MedCon-Message: Read fallback format DICOM 3.0
(X)MedCon-Message: Files overwrite    is ON
(X)MedCon-Message: Color 24 bits RGB  is ON
(X)MedCon-Message: DICM Reading <dicom.dcm> ...
Jun 17 11:28:27 log[16548]: warning: LJPG compiled with 4096-wide image limit
Jun 17 11:28:27 log[16548]: warning: Check out 'jpegutil.c' file to increase
Jun 17 11:28:27 log[16548]: error: Decompression failed
Jun 17 11:28:27 log[16548]: error: No images found

(process:16548): (X)MedCon-WARNING **: Reading: DICM Error reading file

I tried recompiling and setting MDC_LJPG_LIMIT to much larger values (as much as 400x larger) and the same exact message (even saying the limit was set at 4096, not the newer value) was

Then I tried with mitools and I get a different kind of error:

Code:

$ miconv dicom.dcm resultado/
FileIO    |FileIO.autoread : Reading format DICOM
E: can't change to unencapsulated representation for pixel data
E: can't determine 'PhotometricInterpretation' of decompressed image
E: mandatory attribute 'PhotometricInterpretation' is missing or can't be determined
FileIO    |ERROR: DicomFormat.read : Unable to load DICOM image dicom.dcm - MissingAttribute
FileIO    |ERROR: FileIO.autoread : Cannot read file dicom.dcm
Data      |ERROR: miconv.main : autoread failed

What's going on?

eantoranz · 06-17-2013, 01:33 PM

After using dcmj2pnm I was able to see the image and it's over 4096-pixel wide. I think the problem with medcon is that even though I change the limit in jpegutil.c, it's apparently not accounted for in compilation. Why is that?

eantoranz · 06-17-2013, 02:28 PM

I think it's a problem in main.c. It has the limit hard coded there instead of using the limit set in jpegutil.c

Code:

int mdc_dicom_decompress(SINGLE *s, ELEMENT *e)
{
  switch (encapsyntax)
  {
    case COMPRESSED_RLE     :
        if (mdc_dicom_decomp_rle (stream,(U16*)e->value.OB,e->length))
          return(-1);
        break;
    case COMPRESSED_LOSSLESS:
        if (s->w > 4096) {
          dicom_log(WARNING,"LJPG compiled with 4096-wide image limit");
          dicom_log(WARNING,"Check out 'jpegutil.c' file to increase");
          return(-2);
        }
        if (mdc_dicom_decomp_ljpg(stream,(U16*)e->value.OB,e->length
                                        ,(unsigned)s->alloc*s->samples))
          return(-2);
        break;
    case COMPRESSED_LOSSLY  :
    default:
        /* no valid decompressor */
          return(-3);
  }

  return(0);

}