variation on label to image pointer (PDS)

[thare]

We have uncovered a defect for the PDS image type when using detached labels. Unfortunately, it was not written into the original PDS reader as the only cases that were accounted were:

1. ^{IMAGE = 3}
2. ^{IMAGE = "GLOBAL_ALBEDO_8PPD.IMG"}
3. ^{IMAGE = "MEGT90N000CB.IMG"}
4. ^{SPECTRAL_QUBE = 5 for multi-band images}

where 1 is an in-line label and the skipbyte = 3. where 2,3 points to a detached image with implied skipbyte = 0. where 4 is an in-line label and a skipbyte = 5. The "SPECTRAL_QUBE" just says it is multi-band even though there is a BANDS keyword.

so the new style that has been encounter is:

5. ^{IMAGE = ("DTEEC_008669_1705_009025_1705_A01.IMG", 2)}

where the label is pointing to a detached image but still requires a skipbyte of 2 into the file.

I guess we might want to account for (essentially the same thing as above).

5. ^{SPECTRAL_QUBE = ("DTEEC_008669_1705_009025_1705_A01.IMG", 2)}

test file (sorry so large - 500MB) ​ftp://pdsimage2.wr.usgs.gov/pub/pigpen/.temp/DTEEC_008669_1705_009025_1705_A01.zip

note: this image has a duplicate embedded PDS label (which is why we need the skipbytes - don't ask me why) so gdalinfo will work correctly for the *.IMG alone. It will also appear to work correctly for the *.LBL but it will use a skipbyte of 0 not 2. If you request -stats it will fail with some noise at the top.

thanks, Trent