applying multiple masks

[dhalliday]

I am loving my Pix...(!!!)
Recently I was processing M33;
http://www.flickr.com/photos/daveh56/4026715021/sizes/l/

and trying to mask the core,AND the background, at the same time...(with two seperate L masks...)
Maybe this is a crude way to adjust the histo ...but this is how I have been doing it.
I tried to "drop" both masks on the image.....but it did not seem to work...
Is this "multiple masking" possible..?

any other suggestions on this image...I am all ears

Dave

[Simon Hicks]

Hi Dave,

The only way I would know how to do it would be to add the two masks together in PixelMath or use the max function in PixelMath. Either way you create just one mask with the features of both in....then apply the one mask. Maybe someone has a better way?

Cheers
         Simon

[Carlos Milovic]

Not better, but another option is to multiply both masks to create one. Or use the "Screen" operator: 1-(1-Mask1)*(1-Mask2)

[mmirot]

These pixel math operations is difficult for us "mouse only guys". 
Remembering the syntax is too hard, I am running low on gray matter.
Perhaps Juan could and these as preset operations to "layers" when he gets around to adding vector graphics?

Max

[Niall Saunders]

Hi Max,

Yes - this seems to be a good 'precursor' to 'layers'.

However, all you need to do is enter the PixMath formula(e) once - and then just drag-drop the Process Icon onto a PI workspace. Once there, you can save it to disk, having named it something useful first.

This will allow you to reload it in the future (perhaps 'Merging' it with existing Workspace icons) - making it really easy to re-use.

It also does 'train your brain', which is sometimes as much fun as just 'pointing and clicking' - and you will also get a feel for what Juan will eventually, no doubt, bring to PI by way of 'layers'.

Cheers,

[h0ughy]

These pixel math operations is difficult for us "mouse only guys". 
Remembering the syntax is too hard, I am running low on gray matter.
Perhaps Juan could and these as preset operations to "layers" when he gets around to adding vector graphics?

Max

LOL i couldnt agree more, though i am very interested in this process

[Carlos Milovic]

A proposal for multiple masks (mainly for Juan, but suggestions are wellcome... release 1.6 or higher):

The new mask system should allow to add an ilimited amount of images that will act as masks. These images should be operated in some of predefined ways, all the same operator (for more customized options, standard PixelMath procedures should be made to create the composite mask), to create a composite mask that is stored as a temporary file.
This composite mask should be linked to all the operand images (individual masks) and track if there has been any change to them. If so, next time a process is applied to the masked image, the composite mask should be recalculated. If there is no change to the individual masks, no recalculation is needed, of course.

To operate the images we should use these standard procedures: Min, Max, Median, Multiply and Screen.


What do you think?

[Simon Hicks]

Sounds like a very useful feature Carlos. I know I would use it.

[mmirot]

That would be great Carlos.
A simple way of doing composite to images operations would be great. That is... Max Min, ave etc.
Perhaps weighting like 80% image A and 20% B too. ( I know we have other modules that do this to now).
You might consider a drag and drop approach.

Max

[Carlos Milovic]

Weighting complicates things a lot