The following rules were changed :

Skinning Background images must not exceed a width of 1920 pixels and a height of 1200 pixels. Images with lower vertical or horizontal resolutions than that of the player's will be upscaled to fit the entire screen.

Storyboarding Storyboard images must not exceed a width of 1920 pixels and a height of 1200 pixels. The storyboard editor works based on osu! pixels with an internal maximum width of 854 pixels and a height of 480 pixels. If you are using an image bigger than that, you may need to scale accordingly.

So as of now the following rule is dropped from the Ranking Criteria:

The maximum dimensions for tall or wide scrolling images are 640x1440 and 1920x480 respectively. This is for the sake of gameplay performance, image loading time, and filesize.

These changes are in effect immediately.

Hi!As many flooded me with question regarding this change and if maps are rankable with it now (Spoiler: yes.), here's what has changed for you by implementing this change into the game:We didn't view a special regulation for entire images for tall and wide scrolling images as necessary, as 1920x1200 pixels for everything should be well enough for every fancy stuff we could think of. If you need more space, you can always choose to separate your really huge image into several slightly less huge images for the sake of getting by that wide scrolling image rule.As this was a dev-side change and a limitation was lifted from background resolutions, the limit was updated mostly (storyboards were using this same limit) and the rule removal is explained above. If you wish to comment on these amendments, use this thread.