## Motivation
This fixes#2493. When the `label_map` is created, the index for ignored
classes was being set to -1, whereas the index that is actually ignored
is 255. This worked indirectly since -1 was underflowed to 255 when
converting to uint8.
The same fix was made in the 1.x by #2332 but this fix was never made to
`master`.
## Modification
The only small modification is setting the index of ignored classes to
255 instead of -1.
## Checklist
- [x] Pre-commit or other linting tools are used to fix the potential
lint issues.
- _I've fixed all linting/pre-commit errors._
- [x] The modification is covered by complete unit tests. If not, please
add more unit test to ensure the correctness.
- _No unit tests need to be added. Unit tests that are affected were
modified.
- [x] If the modification has potential influence on downstream
projects, this PR should be tested with downstream projects, like MMDet
or MMDet3D.
- _I don't think this change affects MMDet or MMDet3D._
- [x] The documentation has been modified accordingly, like docstring or
example tutorials.
- _This change fixes an existing bug and doesn't require modifying any
documentation/docstring._
## Motivation
I want to fix a bug through this PR. The bug occurs when two options --
`reduce_zero_label=True`, and custom classes are used.
`reduce_zero_label` remaps the GT seg labels by remapping the zero-class
to 255 which is ignored. Conceptually, this should occur *before* the
`label_map` is applied, which maps *already reduced labels*. However,
currently, the `label_map` is applied before the zero label is reduced.
## Modification
The modification is simple:
- I've just interchanged the order of the two operations by moving 4
lines from bottom to top.
- I've added a test that passes when the fix is introduced, and fails on
the original `master` branch.
## BC-breaking (Optional)
I do not anticipate this change braking any backward-compatibility.
## Checklist
- [x] Pre-commit or other linting tools are used to fix the potential
lint issues.
- _I've fixed all linting/pre-commit errors._
- [x] The modification is covered by complete unit tests. If not, please
add more unit test to ensure the correctness.
- _I've added a unit test._
- [x] If the modification has potential influence on downstream
projects, this PR should be tested with downstream projects, like MMDet
or MMDet3D.
- _I don't think this change affects MMDet or MMDet3D._
- [x] The documentation has been modified accordingly, like docstring or
example tutorials.
- _This change fixes an existing bug and doesn't require modifying any
documentation/docstring._
* Support for custom classes
* Fix test
* Fix pre-commit
* Add pipeline logic for custom classes
* Fix minor issues, fix test
* Fix issues from PR review
* Fix tests
* Remove palette as str
* Rename old_to_new_ids to label_map
* Test for load_anns
* Remove get_palette function
* fixed temp
* Add subset of palette, remove palette as arg
* minor update
Co-authored-by: Jiarui XU <xvjiarui0826@gmail.com>
