Index: trunk/psModules/src/imcombine/pmPSFEnvelope.c
===================================================================
--- trunk/psModules/src/imcombine/pmPSFEnvelope.c	(revision 25482)
+++ trunk/psModules/src/imcombine/pmPSFEnvelope.c	(revision 25485)
@@ -126,7 +126,21 @@
             psString string = NULL;     // String with values
             psStringAppend(&string, "PSF %d: ", i);
+            float x = numCols / 2.0, y = numRows / 2.0; // Coordinates of interest
             for (int j = 4; j < psf->params->n; j++) {
-                double val = pmTrend2DEval(psf->params->data[j], numCols/2.0, numRows/2.0);
-                psStringAppend(&string, "%lf ", val);
+                double val = pmTrend2DEval(psf->params->data[j], x, y);
+                switch (psf->psfTrendMode) {
+                  case PM_TREND_POLY_ORD:
+                  case PM_TREND_POLY_CHEB:
+                    err = NAN;
+                    break;
+                  case PM_TREND_MAP: {
+                      pmTrend2D *trend = psf->params->data[j];
+                      err = psImageUnbinPixel(x, y, trend->map->err, trend->map->binning);
+                      break;
+                  }
+                  default:
+                    psAbort("Unsupported mode: %x", psf->psfTrendMode);
+                }
+                psStringAppend(&string, "%lf %lf   ", val, err);
             }
             psTrace("psModules.imcombine", 1, "%s\n", string);