Creating mask based on downsized frame

[yup]

Hi folk!
I want create mask from downsized frame and after upsize mask for work with source frame.
Script:
source=last#720x288
downsized=source.SimpleResize(720,144)
maskdown=downsized.maskcreation
mask=maskdown.LanczosResize(720,288)

Correct? I do not need use "src_left", "src_top", "src_right", "src_top" for right downsizing and back upsizing.
yup.

[Comatose]

It might work, but yeah - those resizer arguments are for cropping.
e.g. crop(1,1,1,1).lanczosresize(100,100) is the same as lanczosresize(100,100,1,1,1,1) (but you can also use fractions when cropping inside the resizer)