by Dan Coe (ACS Science Team, JHU)

SExSeg is a new program that forces SExtractor to run using a pre-defined segmentation map (the definition of objects and their borders).  The defined segments double as isophotal apertures.

Input:

• detection image
• segmentation map
• presumably from running SExtractor (or FOCAS or wavelet detection...) on your detection image
• You may also edit the segmentation map before feeding it into SExSeg. This can be useful to fix any egregious segmentation, to insert apertures in "blank" parts of the field, to eliminate pixels where objects overlap each other...
• SExSeg input parameters (in a .sexseg file)

Output:

• catalog
  
• ID numbers correspond to definitions in segmentation map.
  
• All SExtractor output can be passed to the final output catalog.  However, shape information may be affected by the definition of the objects.  (I haven't looked into this carefully yet.)
  

For more details, see:
Usage & Input Parameters  sexseg det.fits segm.fits <anal.fits, -c anal.sexseg, other options>


Download & Run SExSeg


How SExSeg works



Performance  SExSeg vs. SExtractor: UDF NIC3



As featured in our UDF Catalog paper (accepted by AJ, posted to astro-ph).


Now packaged with the all-in-one photometric package:


Color Measurement  Learn how ColorPro measures accurate colors across images of variable seeing
 
Isophotal magnitudes have been shown to yield the most robust color measurements

high S/N region

avoid contamination

for more details, see Txitxo's Faint Counts paper - Benitez '03