INVENTORY

INVENTORY

STScI • ACDSD • MAST • CASB {•subtitle}

Products

GSC

DSS

GSPC

Science

Publications

Data Access

Related Science

Missions

HST

GEMINI

VLT

NGST

Virtual Observatory

XMM

Facilities

Plate Scanning

COMPASS ooDB

Staff Pages

Last Updated Jan 2001

Purpose :

Detect objects in the image and compute basic parameters.

Procedure :

This is based upon the published ROE COSMOS algorithm which connects a minimum number of pixels that are brighter than a threshold level above sky. Once an object has been completed, its size, integrated density and moments are computed from which parameters such as x,y and shape are calculated. For efficiency a small box around each object is extracted and saved in the Cutout IMage file (CIM) with associated header file (CIH). This can only be done for objects contained in memory so there is a size limit (typically 50 pix. in y), with larger objects being extracted in a second step (Auxcutout).

Calling Sequence :

INVENTORY imagefile

[/XRANGE=(lx,ux)

[/YRANGE=(ly,uy)

[/MINAREA=m] minimum connected pixels for object

[/NSIGMA=n] detection threshold of n.sky sigma {def=3}

[/THRESHOLDS=(t1..t16) Up to 16 specified thresholds

{default will compute 16 levels from nsigma to saturation}
{if disable the sky subtraction then the thresholds levels are: 4000,5000,6000,7000,8000,9000,10000,11000,12000,13000, 14000,15000,16000,17000,19000,21000}

[/DENSITY=d] typical density value {def=7300}

[/[no]SKYSUB] perform sky subtraction

[/[no]OOP] create the OOP binary inventory file {default}

[/TEXT] create ascii file of inventory

[/INV] create the INV binary inventory file {default do not create}

[/SEGMENTSTOP]

[/FUNCTION=option] apply density transformation

Linear {default}
Bilog
Tsubaki

[/TOLERANCE=t] {def=0.0001}

[/LINES=l] Number of lines to keep in memory {def=50}

[/NOCUTOUT] Do NOT create cutout files

[/CUTOUTMAXSIZE=m] Max.size of cutout {def=50}

[/CUTOUTMINMARGIN=m] Min.margin around object {def=2}

[/CUTOUTEXPANSIONFACTOR=m] Scale factor*objectsize {def=1.5}

[/WEIGHTING=option] apply weighting for weighted moments

Area
Density {default}
Intensity

[/WEIGHTPRINT]

Availability :

GSSS AXP - yes
GSSS VAX - yes
PIXELS - no

History/Author :

Version/Date	Developer	Inst.	Comment
-	Barry Lasker	STScI	Original Implementation
-	Vicki Laidler	STScI	Cutouts added
-	Brian McLean	STScI	Integrated into pipeline
20-May-1996	George Hawkins	STScI	Increased param_array_length to 4096 to allow inventory to work on bad areas on edge of plates.
30-May-1996	Andrea Zacchei	CRA/OATo	Substitution OOP/INV
22-Nov-1996	Vicki Laidler	STScI	Fix to inventory cutout generator which caused wrong results in inv/oop files if cutouts were enabled.