MaskedStretch

MikeM

At what point in the non-linear processing step should you use MaskedStretch?  For example, should you do it after Arcsinh and CurvesTransformation or before?  I know this depends on the actual frame but just needing a general idea of when to apply this.

BlockHead

Hi Mike,

I think the general idea of masked stretch is that it is applied to get a linear image- into a non-linear state and take advantage of the masking effect it employs on the brightest elements of the image. So it is likely (but not necessarily required) that you would do this before CurvesTransformation if you are using it to brighten the image. In a similar way, ArcSinh stretch is also a non-linear stretch. So you need to pick the one that is most important. Different data requires different stretching. Some color data (the RGB of LRGB) does very well with masked stretch followed by a color saturation increase. ArcSinh is a dangerous creature... use it with care- there are a number of artifacts it makes with respect to stars.

-the Blockhead