id	summary	reporter	owner	description	type	status	priority	milestone	component	version	severity	resolution	keywords	cc
3940	PDS positioning and xy sign issues.	warmerdam	warmerdam	"PDS has many registration issues across the different releases. Thus not only are there 0.5 to 1.5 pixel shifts, there are even projection offset that are wrongly negated. To mitigate this ""-co"" options need to be defined for PDS to allow a user to override the defaults. Please change as you see fit (e.g. like if -co options are too long).

~line 290-300, overwrite whole comment section and sections:
{{{
    /***********   Grab LINE_PROJECTION_OFFSET ************/
    /***********   Grab SAMPLE_PROJECTION_OFFSET ************/

//-----------------New code to overwrite (untested) -----

    // Calculate upper left corner of pixel in meters from the upper left center pixel sample/line offsets.
    // It doesn't mean the defaults will work for every PDS image, as these values are used inconsistantly.
    // Thus we have included conversion options to allow the user to override the documented PDS3 default.
    // Jan. 2011, for known mapping issues see GDAL PDS page or mapping within ISIS3 source (USGS)
    // $ISIS3DATA/base/translations/pdsProjectionLineSampToXY.def
   
    // defaults should be correct for what is documented in the PDS3 standard
    double   dfSampleOffset_Shift = -0.5;
    double   dfLineOffset_Shift = -0.5;
    double   dfSampleOffset_Mult = -1.0;
    double   dfLineOffset_Mult = 1.0;

    if( CSLFetchNameValue(papszOptions,""SampleProjOffset_Shift"") != NULL )
    {
        dfSampleOffset_Shift = atof(CSLFetchNameValue(papszOptions,""SampleProjOffset_Shift""));
    }
    if( CSLFetchNameValue(papszOptions,""LineProjOffset_Shift"") != NULL )
    {
        dfLineOffset_Shift = atof(CSLFetchNameValue(papszOptions,""LineProjOffset_Shift""));
    }
    if( CSLFetchNameValue(papszOptions,""SampleProjOffset_Mult"") != NULL )
    {
        dfSampleOffset_Mult = atof(CSLFetchNameValue(papszOptions,""SampleProjOffset_Mult""));
    }
    if( CSLFetchNameValue(papszOptions,""LineProjOffset_Mult"") != NULL )
    {
        dfLineOffset_Mult = atof(CSLFetchNameValue(papszOptions,""LineProjOffset_Mult""));
    }

    /***********   Grab LINE_PROJECTION_OFFSET ************/
    value = GetKeyword(""IMAGE_MAP_PROJECTION.LINE_PROJECTION_OFFSET"");
    if (strlen(value) > 0) {
        yulcenter = (float) atof(value);
        dfULYMap = ((yulcenter + dfLineOffset_Shift) * -dfYDim * dfLineOffset_Mult);
        //notice dfYDim is negative here which is why it is again negated here
    }
    /***********   Grab SAMPLE_PROJECTION_OFFSET ************/
    value = GetKeyword(""IMAGE_MAP_PROJECTION.SAMPLE_PROJECTION_OFFSET"");
    if( strlen(value) > 0 ) {
        xulcenter = (float) atof(value);
        dfULXMap = ((xulcenter + dfSampleOffset_Shift) * dfXDim * dfSampleOffset_Mult);
    }
}}}


For my notes - known PDS line/sample offset oddities

 

from:  $ISIS3DATA/base/translations/pdsProjectionLineSampToXY.def

{{{

Object = ProjectionOffsetMults
  #  MAGELLAN - MIDR
  #  Magellan MIDR file labels were converted from VICAR labels to PDS
  #   labels, and in this conversion the sample/line offsets were rounded
  #   to whole numbers; subpixel accuracy was lost. Because of this, we'll
  #   never exactly match the latitude/longitude but we can be close.
  Group = Selection
    Keyword = ""DATA_SET_ID""
    Pattern = ""MGN-V-RDRS-5-MIDR""
    xMult   = -1.0
    yMult   = 1.0
    xOff    = -0.5
    yOff    = 1.0
  End_Group

 

  # VIKING ORBITER
  Group = Selection
    Keyword = ""DATA_SET_ID""
    Pattern = ""VO1/VO2-M-VIS-5-DIM-V1.0""
    xMult = -1.0
    yMult =  1.0
    xOff = -1.0
    yOff = -1.0
  End_Group

 

  #  MAGELLAN - FMAP
  Group = Selection
    Keyword = ""DATA_SET_ID""
    Pattern = ""MGN-V-RDRS-5-DIM""
    xMult   = 1.0
    yMult   = -1.0
    xOff    = 1.5
    yOff    = 1.5
  End_Group

 

  #  CASSINI RADAR
  Group = Selection
    Keyword = ""DATA_SET_ID""
    Pattern = ""CO-SSA-RADAR""
    xMult   = -1.0
    yMult   = 1.0
    xOff    = 0.5
    yOff    = 0.5
  End_Group

 

  #  KAGUYA TERRAIN CAMERA
  Group = Selection
    Keyword = ""DATA_SET_ID""
    Pattern = ""TC_MAP""
    xMult   = 1.0
    yMult   = 1.0
    xOff    = -0.5
    yOff    = -0.5
  End_Group

 

  #  STANDARD PDS
  #  Should always be last
  Group = Selection
    Keyword = ""PDS_VERSION_ID""
    Pattern = ""PDS3""
    xMult   = -1.0
    yMult   = 1.0
    xOff    = -0.5
    yOff    = -0.5
  End_Group
End_Object
}}}

from: http://pds.nasa.gov/documents/psdd/PSDDmain_1r71.pdf (check!)

LINE PROJECTION OFFSET REAL <pixel>
The line projection offset element provides the line offset value of the map projection origin position from the line
and sample 1,1 (line and sample 1,1 is considered the upper left corner of the digital array). Note: that the positive
direction is to the right and down.

SAMPLE PROJECTION OFFSET REAL <pixel>
The sample projection offset element provides the sample offset value of the map projection origin position from line
and sample 1,1 (line and sample 1,1 is considered the upper left corner of the digital array). Note: that the positive
direction is to the right and down."	defect	assigned	normal		GDAL_Raster	unspecified	normal		PDS	thare