Segmentation using vector mask
Hi everyone!
We are doing some project work and are using DOF segmented through eCognition. An interesting notion I saw: I wanted to speed up the segmentation process by first doing a vector-based segmentation to limit the area of interest and then segment only the AOI. BUT when I do this, the segmentation time goes up 4 folds and is useless. So I ended up segmenting the whole scene and then applying the vector mask. An interesting thing to notice!
I was sure the first approach would be faster due to limited input from the AOI. :)
Best,
Ivan
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Hi Ivan,
Good approach, but unfortunately the multi-resolution segmentation (MRS) (I am guessing that you are using this Segmentation?!) does have unique behavior regarding the domain. As you might know, the MRS can utilize more than one core, but this is limited to the domain "pixel-level" if the MRS is executed on the domain "image object level" it only can utilize one core. That is the reason why your second approach is faster! First creating all objects using the MRS on "pixel level" and then applying the vector on the image object level.
This knowledge can become handy if you have larger images that you want to run the MRS on.
Cheers,
Matthias
Interesting! And good to know!
Maybe to implement a provided vector mask as a 1/0 mask layer that then MRS ignores? Like a 4th layer in RGB imagery that stops the segment when reaches layers 0 value pixel. :)
Just a quick idea.
Cheers!
Ivan
This actually would then be super fast!!!
You could use the vector mask to define "no data" values of the project. In this case the MRS would ignore all no data areas and not create objects there! Yes! This could be even faster! Great idea!
Cheers,
Matthias
This sounds like a good workaround!
Would be amazing if you could add "mask layer" option within the segmentation algorithm :)
Which would define "no data" only for that process and remove it once executed :)
Best regards,
Ivan
Hi Matthias!
Which algorithm allows me to define no data values by vector in eCog? I want to try this out.
Best,
Ivan