Changeset 30903 for branches/eam_branches/ipp-20110213/psphot/src/psphotCullPeaks.c

Timestamp:

Mar 14, 2011, 3:07:22 PM (15 years ago)

Author:

eugene

Message:

psphotSignificanceImage now returns a pmReadout so we can keep the smoothed signal image as well as the S/N image; psphotCullPeaks (and pmFootprintCullPeaks) now uses the smooted image to cull the peaks -- this deals better with low-significance detections are large, low-surface brightness areas

File:

• branches/eam_branches/ipp-20110213/psphot/src/psphotCullPeaks.c (modified) (4 diffs)

branches/eam_branches/ipp-20110213/psphot/src/psphotCullPeaks.c

@@ -6 +6 @@
 psErrorCode
 psphotCullPeaks(const pmReadout *readout,   // the image wherein lives the footprint
+                const pmReadout *signifR, // smoothed image and significance
                 const psMetadata *recipe,
                 psArray *footprints) {  // array of pmFootprints
@@ -26 +27 @@
     psAssert (status, "cannot find SKY_STDEV in readout->analysis");
 
-    const float MIN_THRESHOLD = nsigma_min*skyStdev;
+    // the sky has been smoothed, so we need to scale down the raw sky stdev by this amount:
+    float scaleFactor = psMetadataLookupF32(&status, readout->analysis, "SIGNIFICANCE_SCALE_FACTOR");
+    if (!status) scaleFactor = 1.0;
+
+    const float MIN_THRESHOLD = nsigma_min*skyStdev / sqrt(scaleFactor);
     
     // for saturated stars, we should be somewhat more agressive about culling: instead of
@@ -36 +41 @@
     // fStdev = 0.005, stdev_pad = 0.011*40k = 400
     // threshold = 40k - 4*400 = 38400 
-
-    // in practice, we should make the threshold in such a case more like 0.5 * saturation...
+    // this gives too tight of a tolerance on the bright stars
+    // in practice, we should make the threshold much lower.  
+    // below I am using 0.05 * saturation (eg, 2000 DN above sky in a GPC1 image)
 
     float SATURATION = NAN;
@@ -72 +78 @@
         }
 
-        if (pmFootprintCullPeaks(readout->image, readout->variance, fp, nsigma_delta, fPadding, MIN_THRESHOLD, max_threshold) != PS_ERR_NONE) {
+        // if we cull using the significance image, then the thresholds are different
+# if (0)
+        if (pmFootprintCullPeaks(signifR->image, readout->variance, fp, nsigma_delta, fPadding, MIN_THRESHOLD, max_threshold, true) != PS_ERR_NONE) {
             return psError(PS_ERR_UNKNOWN, false, "Culling pmFootprint %d", fp->id);
         }
+# endif
+# if (1)
+        if (pmFootprintCullPeaks(signifR->image, signifR->variance, fp, nsigma_delta, fPadding, MIN_THRESHOLD, max_threshold, false) != PS_ERR_NONE) {
+            return psError(PS_ERR_UNKNOWN, false, "Culling pmFootprint %d", fp->id);
+        }
+# endif
+# if (0)
+        if (pmFootprintCullPeaks(readout->image, readout->variance, fp, nsigma_delta, fPadding, MIN_THRESHOLD, max_threshold, true) != PS_ERR_NONE) {
+             return psError(PS_ERR_UNKNOWN, false, "Culling pmFootprint %d", fp->id);
+        }
+# endif
+
         float dtime = psTimerMark ("psphot.cull.footprints");
         if (dtime > 1.0) {