PixInsight Forum (historical)

PixInsight => General => Topic started by: alanrock on 2018 November 29 08:53:16

Title: Linear Fit/Invalid Geometry
Post by: alanrock on 2018 November 29 08:53:16

I'm trying to do a linear fit between my L image which is binned 1x1 and my R which is binned 2x2, and I get the invalid geometry error. Probably a dumb question, but is this something that you just cannot do if the images are binned differently? If so, is there any way to achieve the same thing?
Thanks,
Alan

Title: Re: Linear Fit/Invalid Geometry
Post by: ngc1535 on 2018 November 29 09:28:09

Yep, the images need to be the same size. Linear Fit does a pixel-to-pixel match in each image. This doesn't work if the images are different sizes. You can resample one of the images (likely upsample the binned image) to get things to work out.
-adam

Title: Re: Linear Fit/Invalid Geometry
Post by: alanrock on 2018 November 29 10:33:23

And how does one upsample an image?

Title: Re: Linear Fit/Invalid Geometry
Post by: msmythers on 2018 November 29 10:50:41

Alan

PI has 2 tools for re-sampling. IntegerResample and Resample. For your use case IntergerResample would be the one to use.


Mike

Title: Re: Linear Fit/Invalid Geometry
Post by: alanrock on 2018 November 29 11:50:26

Thank you! I assume I need to downsample the R,G and B before I can combine, is that right?