PixInsight Forum (historical)

PixInsight => Wish List => Topic started by: fneyer on 2017 June 17 12:33:07

Title: Additional Flexibility in DynamicBackgroundExtraction
Post by: fneyer on 2017 June 17 12:33:07

Hi Juan,

I think it is a relatively easy feature to add: Could you please allow the axis of symmetry (horizontal and vertical) to be rotated by a user defined angle?

I sometimes need to correct for a linear gradient and I do this by setting two samples with either vertical or horizontal symmetry enabled. The resulting background model is a linear gradient but only with either horizontal or vertical orientation. I'm missing all the other orientations or is there another way to do it?

Thanks!
Fabian

Title: Re: Additional Flexibility in DynamicBackgroundExtraction
Post by: Juan Conejero on 2017 June 17 13:02:13

Hi Fabian,

Nice idea. I think this can be implemented in the new DynamicBackground tool (the successor to DBE), which will be released after version 1.8.5 of PixInsight, probably in September. Thank you.

A linear gradient with arbitrary orientation can be generated quite easily with PixelMath. I'll work on a general expression and will post it here.

Title: Re: Additional Flexibility in DynamicBackgroundExtraction
Post by: fneyer on 2017 June 18 05:45:34

Great to hear you will implement this, thank you Juan!

I'm sure there is a relatively easy way to create a linear gradient with PixelMath. The hard part (I think), however, is to correctly set the steepness of this 2D plane. With DBE this easy to do (the two positions where you want the lightness to be equal are set with two samples and DBE estimates the corresponding background values that define the slope steepness). I like this easy and very fast approach with DBE and I'm curious to see if you can do something similar with PixelMath.

Fabian