Changeset 41958 for branches/eam_branches/ipp-20211108

Timestamp:

Dec 3, 2021, 11:06:56 AM (5 years ago)

Author:

eugene

Message:

limit max value of variance to 9e7

File:

• branches/eam_branches/ipp-20211108/psModules/src/imcombine/pmStack.c (modified) (1 diff)

branches/eam_branches/ipp-20211108/psModules/src/imcombine/pmStack.c

@@ -1756 +1756 @@
               int P75 = 0.75*nGoodClip + Nlo;
               float rawSigma = 0.74*(pixelData->data.F32[P75] - pixelData->data.F32[P25]);
-              varValue = PS_SQR(rawSigma) / (float) nGoodClip; // sigma_mean = sigma_meas / sqrt(Nmeas) -> var_mean = var_meas / Nmeas
+              varValue = PS_MIN(9e7, PS_SQR(rawSigma) / (float) nGoodClip); // sigma_mean = sigma_meas / sqrt(Nmeas) -> var_mean = var_meas / Nmeas
+              // XXX the upper limit of 9e7 is set to match the output
+              // format (STK_UNIONS) which can only represent values up to that limit.
+              // perhaps it would be better to saturate the output image in psFits
+              // rather than here.  
             }