# imageCentroid

Computes the image statistics and the center of mass (centroid) using scipy's center_of_mass function. See also imagePeak.

### Usage:

```au.imageCentroid(imgfile, threshold=0, axis3channel=None, axis4channel=None,
fractionalThreshold=None, aperture=None, crpixOffset=None,
```
• threshold: ignore pixel values below this (positive) level when computing the centroid
• axis3channel: which channel to use on 3rd axis (default=all)
• axis4channel: which channel to use on 4th axis (default=all)
• fractionalThreshold: sets the threshold with respect to the peak pixel value of the image
• axis3channel: which channel to use on 3rd axis (default=all)
• axis4channel: which channel to use on 4th axis (default=all)
• aperture: diameter in arcsec within which to measure flux density
• crpixOffset: compute offset from ref pixel in units: 'pixel', 'arcsec', or 'rad'
• verbose: if True, print all flux stats
• normalize: if threshold is set, then set all pixel values to 1.0
• radec: if True, return the RA and Dec instead of the pixel coordinates
• blc,trc: define the region to assess sigma for sigmaThreshold option
• keepThresholdImage: write a new image corresponding to the threshold
• radialThreshold: maximum radius in pixels from image center to consider when threshold is set (use this to avoid distant noise spikes)

### Example:

```CASA <3>: au.imageCentroid('X254.ms.DA62.spw17.sf6.f7.5.image')
Image statistics: mean=0.010070 median=0.000000 max=1.155239 min=-0.034252
Out[3]: (47.189305839062037, 48.143440396198635)
```

-- ToddHunter - 2013-11-03
Topic revision: r5 - 2015-02-05, ToddHunter

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