Index: branches/2dbias/ippconfig/gpc1/ppImage.config
===================================================================
--- branches/2dbias/ippconfig/gpc1/ppImage.config	(revision 42719)
+++ branches/2dbias/ippconfig/gpc1/ppImage.config	(revision 42722)
@@ -1667,4 +1667,71 @@
 END
 
+# only subtract overscan 
+CHIP_SUB_BIAS	METADATA
+  BASE.FITS          BOOL    FALSE           # Save base detrended image?
+  BASE.MASK.FITS     BOOL    FALSE           # Save base detrended image?
+  BASE.VARIANCE.FITS BOOL    FALSE           # Save base detrended image?
+  CHIP.FITS          BOOL    TRUE            # Save chip-mosaic-ed image? 
+  CHIP.MASK.FITS     BOOL    TRUE            # Save chip-mosaic-ed image? 
+  CHIP.VARIANCE.FITS BOOL    TRUE            # Save chip-mosaic-ed image? 
+  OVERSCAN           BOOL    TRUE            # Overscan subtraction
+  NONLIN             BOOL    FALSE            # apply non-linearity correction 
+  BIAS               BOOL    FALSE           # Bias subtraction
+  DARK               BOOL    FALSE            # Dark subtraction
+  NOISEMAP           BOOL    FALSE
+  REMNANCE           BOOL    FALSE           # Remnance masking
+  SHUTTER            BOOL    FALSE           # Shutter correction
+  FLAT               BOOL    FALSE            # Flat-field normalisation
+  MASK               BOOL    TRUE            # Mask bad pixels
+  MASK.BUILD	     BOOL    TRUE	     # Build internal mask?
+  MASK.BURNTOOL      BOOL    TRUE            # Mask potential burntool trails
+  MASK.AUXMASK       BOOL    FALSE           # augment mask with more restrictive auxiliary mask
+  PATTERN.ROW        BOOL    FALSE           # Row pattern correction
+  PATTERN.CELL	     BOOL    FALSE	     # Cell pattern correction
+  PATTERN.CONTINUITY BOOL    FALSE           # Cell pattern coorection using edge continuity
+  FRINGE             BOOL    FALSE            # Fringe subtraction
+  BIN1.FITS          BOOL    TRUE            # Save 1st binned chip image?
+  BIN2.FITS          BOOL    TRUE            # Save 2nd binned chip image?
+  PHOTOM             BOOL    FALSE            # Source identification and photometry
+  ASTROM.CHIP        BOOL    FALSE           # Astrometry per chip?
+  ASTROM.MOSAIC      BOOL    FALSE           # Astrometry for mosaic?
+  BACKGROUND         BOOL    FALSE           # Subtract background?
+  CROSSTALK.MEASURE  BOOL    FALSE           # Subtract model background?
+END
+
+# only subtract 2D overscan
+CHIP_SUB_2DBIAS	METADATA
+  BASE.FITS          BOOL    FALSE           # Save base detrended image?
+  BASE.MASK.FITS     BOOL    FALSE           # Save base detrended image?
+  BASE.VARIANCE.FITS BOOL    FALSE           # Save base detrended image?
+  CHIP.FITS          BOOL    TRUE            # Save chip-mosaic-ed image? 
+  CHIP.MASK.FITS     BOOL    TRUE            # Save chip-mosaic-ed image? 
+  CHIP.VARIANCE.FITS BOOL    TRUE            # Save chip-mosaic-ed image? 
+  OVERSCAN           BOOL    TRUE            # Overscan subtraction
+  OVERSCAN.2D        BOOL    TRUE            # 2D Overscan model
+  NONLIN             BOOL    FALSE            # apply non-linearity correction 
+  BIAS               BOOL    FALSE           # Bias subtraction
+  DARK               BOOL    FALSE            # Dark subtraction
+  NOISEMAP           BOOL    FALSE
+  REMNANCE           BOOL    FALSE           # Remnance masking
+  SHUTTER            BOOL    FALSE           # Shutter correction
+  FLAT               BOOL    FALSE            # Flat-field normalisation
+  MASK               BOOL    TRUE            # Mask bad pixels
+  MASK.BUILD	     BOOL    TRUE	     # Build internal mask?
+  MASK.BURNTOOL      BOOL    TRUE            # Mask potential burntool trails
+  MASK.AUXMASK       BOOL    FALSE           # augment mask with more restrictive auxiliary mask
+  PATTERN.ROW        BOOL    FALSE           # Row pattern correction
+  PATTERN.CELL	     BOOL    FALSE	     # Cell pattern correction
+  PATTERN.CONTINUITY BOOL    FALSE           # Cell pattern coorection using edge continuity
+  FRINGE             BOOL    FALSE            # Fringe subtraction
+  BIN1.FITS          BOOL    TRUE            # Save 1st binned chip image?
+  BIN2.FITS          BOOL    TRUE            # Save 2nd binned chip image?
+  PHOTOM             BOOL    FALSE            # Source identification and photometry
+  ASTROM.CHIP        BOOL    FALSE           # Astrometry per chip?
+  ASTROM.MOSAIC      BOOL    FALSE           # Astrometry for mosaic?
+  BACKGROUND         BOOL    FALSE           # Subtract background?
+  CROSSTALK.MEASURE  BOOL    FALSE           # Subtract model background?
+END
+
 # Standard chip processing without background subtraction or pattern correction
 CHIP_PRESERVE_BG	METADATA