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<TITLE>Problem with GDAL NITF Image Compression</TITLE>
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<P><FONT FACE="Times New Roman">I just realized if I compress a NITF file with GDAL, the compressed image file cannot be opened by other NITF image viewers. I tested with ELT, ArcMap, and Opticks, all reports some type of error when trying to open a GDAL compressed NITF file. GDAL seems to be the only driver that is capable of reopen a GDAL compressed NITF file.</FONT></P>
<P><FONT FACE="Times New Roman">I tried both C3 and M3 compression options ( JPEG compression), and neither of them works. I also ran NITF validation tool on the compressed file and following error is shown:</FONT></P>
<P><FONT FACE="Times New Roman">‘The combination of Image Representation(IREP) = "YCbCr601" and Image Compression(IC) = "M3" does not allow Image Mode(IMODE) = "B".’ </FONT></P>
<P><FONT FACE="Times New Roman">And if you look at appendix A of NITF specification (2500C), it does not list those parameters as a possible combination. But at the same time I don’t know if the incorrect header supposes affect how other NITF viewer opens the file or not.</FONT></P>
<P><FONT FACE="Times New Roman">I haven't deal with JPEG format much before. So any suggestion on what might went wrong, or anything else I can try is greatly appreciated. </FONT></P>
<P><FONT SIZE=2 FACE="Arial">-Kevin</FONT>
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