Using --no_norm with CLI slows down 3D segmentation[BUG]

[derekthirstrup]

The segmentation of 3d tif stacks is taking 5-6 minutes to process 1 image when --no_norm is used. When the same stacks are processed without --no_norm argument then it takes roughly 20 seconds. I previously denoised and rescaled the images so they do not need to be rescaled again during segmentation. Any ideas why it takes significantly more time with --no_norm option? Seems like it should be faster.