Hi Jony,

The IKSS estimator is not available on the core JavaScript runtime, so you'll have to implement it in JavaScript. For your convenience, here you have it:

`/*`

* Iterative k-sigma Estimator of Location and Scale (IKSS).

*

* Parameters:

*

* x A Vector object with the sample values.

* eps Fractional accuracy. The default value is 1e-6.

*

* Returns an Array object of the form:

*

* [L,S,N,I]

*

* where:

*

* L is the location estimate.

* S is the scale estimate.

* N is the number of non-rejected samples used for estimation.

* I is the number of iterations performed.

*

* If the algorithm does not converge to significant values, one or both of the

* returned location and scale estimates will be zero.

*/

function IKSS( x, eps )

{

if ( eps == undefined )

eps = 1.0e-06;

x.sort();

var N = x.length;

var i = 0;

var j = N;

var s0 = 1;

for ( var it = 1; ; ++it )

{

if ( j - i < 1 )

return [0,0,0,it];

var v = new Vector( x, i, j );

var m = v.median();

var s = Math.sqrt( v.BWMV( m ) );

if ( 1 + s == 1 )

return [m,0,j-i,it];

if ( (s0 - s)/s < eps )

return [m,0.991*s,j-i,it];

s0 = s;

for ( var x0 = m - 4*s; x.at( i ) < x0; ++i ) {}

for ( var x1 = m + 4*s; x.at( j-1 ) > x1; --j ) {}

}

}

To use this function for an image, you have to gather pixel samples into a Vector object, as a result of some limitations in the Math JavaScript object implemented in current versions (this will change in the next version of PixInsight, where a Vector object won't be required, so the IKSS function above will be able to work directly with an Array). For example:

`function ikssOfImage( image )`

{

var A = new Array;

image.getSamples( A );

return IKSS( new Vector( A ) );

}

You'll have to iterate through a set of files, loading the images, calling the above functions, and working with the results. Let me know if you also need help with this.