Scaling is slow when working with large images

[Rorihx]

I have an 6000x6000 image. When I zoom into this, the system is very slow, due to resize operation on full image.
And yes, I want to zoom far in!
Wouldn't it be better to resize the section to display only. (And cut and resize again when scrolling)

[DennisLiu1993]

you can try to resize a region of original image instead of resizing the whole, but it may cause some issues (a few pixel error)