What is purposes of image_width and image_height in heif_item_get_property_transform_crop_borders?

[homm]

There are two parameters for heif_item_get_property_transform_crop_borders function which purposes are not clear to me: image_width and image_height. The queued itemId already should have whole information about size. So two questions:

1. Why we need to customize this sizes?
2. What sizes I should pass? The raw bitmap sizes (ispe_width and ispe_height)? Bitmap sizes after all manipulations applied (width and height)? The current width and height after all already met irot and imir properties?