fix: Fix an error when converting null masks in object_ann and surface_ann

[KSeangTan]

The validator will fail when our mask value is null, this PR fixes that by allowing passing None valueinmask`.

[KSeangTan]

Hi @ktro2828

It seems that I dont have the permission to add reviewers in this PR. Would you mind taking a look? Thanks

[ktro2828]

Thank you for catching!

Could you also update SurfaceAnn.bbox for the case of mask=None?

t4-devkit/t4_devkit/schema/tables/surface_ann.py

Lines 48 to 59 in cde769f

	@property
	def bbox(self) -> RoiLike:
	"""Return a bounding box corners calculated from polygon vertices.
	Returns:
	Given as [xmin, ymin, xmax, ymax].
	"""
	mask = self.mask.decode()
	indices = np.where(mask == 1)
	xmin, ymin = np.min(indices, axis=1)
	xmax, ymax = np.max(indices, axis=1)
	return xmin, ymin, xmax, ymax

def bbox(...) -> RoiLike | None:
    if mask is None:
        return None
    # ...

[ktro2828]

@KSeangTan Also, do you know the database version of the corresponding dataset? Is the latest or old one?

[KSeangTan]

Hi @ktro2828

It's the older database, one of the example is
db_jpntaxi_v1/70891309-ca8b-477b-905a-5156ffb3df65

[ktro2828]

LGTM

@KSeangTan Could fix CI failure in pre-commit?

[KSeangTan]

Hi @ktro2828
I have resolved the pre-commit errors, would you mind proceeding with the merging? Thanks