Incompatible Mask Image

[midnightlightning]

Hi,

I have created a Red mask using ColourMask and used Affinity Photo to edit it and bring it back into PI using tiff files.

It works fine when I apply it (drag) to my RGB image but I get the error message above when I do the same to Lum or Ha images.

EDIT. The Tif file I saved in PI to use in Affinity works fine if I drag it to Lum or Ha images, it's only the version I saved in Affinity and brought back in that wont work.

Any thoughts?

Thanks
Jon

[midnightlightning]

Fixed it.

Saving the file as .png from Affinity worked for all 3 images whereas saving as Tif only worked for the RGB.

No idea why.

[oldwexi]

Your mask put over a Gray image like L and Ha needs to be Gray also.
Means you got an RGB file back from Affinity and have to convert it to Grayscale with the process
ConverttoGrayscale. Uusing this image now as mask on the L and Ha will work properly.
Masks for gray images cant be RGB !

By the way what are you doing to your mask in Affinitiy what could not be done in PI
No need for conversion to tiff and software jumping if you have PI !!!

Gerald

[midnightlightning]

Thanks Gerald, it would have taken me hours to work that out.

I was trying to get a mask of Ha only by using the Colour Mask script to extract the Red from my NBLRGB image. I used Affinity to paint the areas I wasn't interested in black.

I had already added Ha to RGB and now wanted to add Lum. The Red Colour Mask had more red than I needed. I used HT to clip the black point but it still left remnants - which is why I went to Affinity to remove the remnants. I then wanted to use the mask on my Lum when doing a combine of NBRGB and Lum in Pixel Math.

It didn't work even when I sorted the mask out (took me two solid days of processing to get this far!).  No doubt there is a better way but I'm still don't have a clear workflow in my head for HaLRGB and am picking bits out of lots of videos etc.

[RickS]

Hi Jon,

It is possible to use CloneStamp to copy from another image (e.g. one that is all black) over parts of your mask.  Create the black mask with PixelMath expression "0" and appropriate options to create a new monochrome image.

I'm a little confused as to why you used ColorMask to extract red as a representation of Ha when it sounds like you have Ha data.  Wouldn't it be easier to create a mask from the Ha data?

Cheers,
Rick.