JPEG decompression swaps colors e.g. RGB->BGR???

Hi,

I've tried decompressing JPEG-compressed raster data using both
javax.imageio.plugins.jpeg.* (together with the general javax.imageio.* infr
astructure) and the IJG jpeglib C code, but both of these keep swapping RGB 
band ordering of my images to BGR ordering.

The only way I've found to work around this is to specify
JPEGImageReadParam.setSourceBands([b,g,r]), where b, g, and r correspond to 
the band offsets for blue, green, and red bands. Just to give a bit of conte
xt, I've also implemented JPEG compression, which is how I get the raster da
ta to be compressed in the first place. During the JPEG compression process 
I specify a ComponentSampleModel with the band offsets [r,g,b]. I know that 
the JPEG compression works correctly, because the compressed data can be vie
wed in a standard browser with the correct colors.

My questions: Is the color swapping in JPEG decompression a known issue? Why
 does JPEG decompression keep reversing the bands internally? Is it somethin
g with my usage of the API? Is my workaround valid, or does it just "cure th
e symptoms" without fixing the underlying problem?

If anyone can please help me out in getting to the bottom of this, I would r
eally appreciate it.

Thanks,

C.

(My decompression code is below. Just before I call this function, I write t
he data in bis to a file and successfully display it in a standard browser w
ith correct colors, so I am assuming that my compress function is correct an
d I therefore have not included the compression code. )

public static void decompress(BinaryInputStream bis, BinaryOutputStream bos)
{
 ImageReadParam ep = null;
 ImageReader imread = null;
 ImageInputStream iis = null;
 JPEGEncodeParam ep1 = null;
 JPEGQTable[] qtbl_new = null;
 JPEGHuffmanTable[] dchuff = null;
 JPEGHuffmanTable[] achuff = null;
 byte[] outBuffer = null;
 int numBands = 3; //hard coded for clarity
 int method = JPEG_FULL; //hard coded for clarity, but actually the  swappin
g occurs for both full and abbreviated formats.

 try
 {
  Iterator readers = ImageIO.getImageReadersByFormatName("jpeg");
  imread = (ImageReader)readers.next();
  ep = imread.getDefaultReadParam(); 

  iis = ImageIO.createImageInputStream(bis);
  imread.setInput(iis, true);
  qtbl_new = new JPEGQTable[numBands];
  dchuff = new JPEGHuffmanTable[numBands];
  achuff = new JPEGHuffmanTable[numBands];

  double scquality = (double)quality/100.0;
  scquality = jpegQualityScaling(scquality);

  if ((method == JPEG_ABBREV))
  {
   for (int z = 0; z < numBands; z++)
   {
    qtbl_new[z] = JPEGQTable.K2Chrominance.getScaledInstance((float)  scquality
, true);

    dchuff[z] = JPEGHuffmanTable.StdDCChrominance;
    achuff[z] = JPEGHuffmanTable.StdACChrominance;
   }

   ((JPEGImageReadParam)ep).setDecodeTables(qtbl_new, dchuff, achuff);
  }
  int[] bandOffsets = null;

  bandOffsets = new int[numBands];
  int ii = numBands-1;
  for(int i=0; i < numBands; i++)
  {
   if (numBands == 3)
   {
    bandOffsets = ii;
    ii = ii - 1; 
   }
   else
   {
    bandOffsets = i;
   }
  }
  ((JPEGImageReadParam)ep).setSourceBands(bandOffsets);
  BufferedImage decompIm = imread.read(0, ep);
  Raster decompRaster = decompIm.getData();
  //... snipped irrelevant processing of Raster.
  }
 catch (Exception ex)
 {
  try
  {
   iis.close();
  }
  catch (Exception ex1)
  {
  }
  qtbl_new = null;
  achuff = null;
  dchuff = null;
  outBuffer = null;
 }
}