Index: trunk/magic/remove/src/streaksastrom.c
===================================================================
--- trunk/magic/remove/src/streaksastrom.c	(revision 21437)
+++ trunk/magic/remove/src/streaksastrom.c	(revision 24382)
@@ -150,4 +150,100 @@
  
 bool
+SkyToLocal(strkPt *outPt, strkAstrom *astrom, double ra, double dec)
+{
+    // generate a local project using the RA, DEC of the 0,0 pixel of the chip as the
+    // projection center with the same plate scale as the nominal TP->Sky astrometry.
+
+    pmFPA *fpa   = (pmFPA *) astrom->fpa;
+    pmChip *chip = (pmChip *) astrom->chip;
+
+    // find the RA,DEC coords of the 0,0 pixel for this chip:
+
+    psPlane ptTP;
+    psSphere ptSky;
+
+    ptSky.r = ra;
+    ptSky.d = dec;
+    ptSky.rErr = 0.0;
+    ptSky.dErr = 0.0;
+
+    psProject(&ptTP, &ptSky, fpa->toSky);
+
+    outPt->x = ptTP.x;
+    outPt->y = ptTP.y;
+
+    return true;
+}
+
+bool
+LocalToSky(strkPt *outPt, strkAstrom *astrom, strkPt *inPt)
+{
+    // generate a local project using the RA, DEC of the 0,0 pixel of the chip as the
+    // projection center with the same plate scale as the nominal TP->Sky astrometry.
+
+    pmFPA *fpa   = (pmFPA *) astrom->fpa;
+    pmChip *chip = (pmChip *) astrom->chip;
+
+    // find the RA,DEC coords of the 0,0 pixel for this chip:
+
+    psPlane ptTP;
+    psSphere ptSky;
+
+    ptTP.x = inPt->x;
+    ptTP.y = inPt->y;
+    ptTP.xErr = 0.0;
+    ptTP.yErr = 0.0;
+
+    psDeproject(&ptSky, &ptTP, fpa->toSky);
+
+    outPt->x = ptSky.r;
+    outPt->y = ptSky.d;
+
+    return true;
+}
+
+bool
+componentBounds(int *minX, int *minY, int *maxX, int *maxY, strkAstrom *astrom, int numCols, int numRows)
+{
+    // find the bounds of the (padded) chip region in tangent-plane coordinates
+
+    pmFPA *fpa   = (pmFPA *) astrom->fpa;
+    pmChip *chip = (pmChip *) astrom->chip;
+
+    psPlane ptCH, ptFP, TPo, TPx, TPy;
+
+    // coordinate of the chip center:
+    ptCH.x = 0.5*numCols;
+    ptCH.y = 0.5*numRows;
+    psPlaneTransformApply(&ptFP, chip->toFPA, &ptCH);
+    psPlaneTransformApply(&TPo, fpa->toTPA,  &ptFP);
+
+    // coordinate of the chip center + dX/2:
+    ptCH.x = numCols;
+    ptCH.y = 0.5*numRows;
+    psPlaneTransformApply(&ptFP, chip->toFPA, &ptCH);
+    psPlaneTransformApply(&TPx, fpa->toTPA,  &ptFP);
+
+    // coordinate of the chip center + dY/2:
+    ptCH.x = 0.5*numCols;
+    ptCH.y = numRows;
+    psPlaneTransformApply(&ptFP, chip->toFPA, &ptCH);
+    psPlaneTransformApply(&TPy, fpa->toTPA,  &ptFP);
+
+    // half-lengths of the two sides in tangent-plane coords:
+    double xSize = hypot (TPx.x - TPo.x, TPx.y - TPo.y);
+    double ySize = hypot (TPy.x - TPo.x, TPy.y - TPo.y);
+    double radius = hypot (xSize, ySize);
+
+    // define the region encompassed by the radius with some padding:
+    *minX = TPo.x - 1.1*radius;
+    *minY = TPo.y - 1.1*radius;
+    *maxX = TPo.x + 1.1*radius;
+    *maxY = TPo.y + 1.1*radius;
+
+    return true;
+}
+
+bool
 skyToCell(strkPt *outPt, strkAstrom *astrom, double ra, double dec)
 {