* supports for DETR transformer

* unit test with small data to avoid out of memory in CI

* use batch size 1 for unit test to avoid out of memory

* move transformer into utils folder and use more small data for unit test

* reformat docstring

* add more detailed docstring

* reforamt

* reformat and add build_transformer (#3866)

* Supports for DETR position embedding (#3850)

* supports for DETR position embedding

* reformat docstring

* reformat

* move transformer_head folder into utils

* remove unnecessary comments

* reformat

* reformat

* reformat docstring

* reformat

* add optional for default parameters

* add comments for unit test

* avoid inplace in MultiheadAttention and add optional add_residual for FFN

* Supports for DETR inference (#3941)

* fix forward in FFN

* supports detr inference mode with batchsize 1

* add docstring for DETR in detr.py

* reformat and add doctest for TransformerHead

* reformat, and move the mask construction from simple_test in detr.py to the forward process of transformer_head

* rename detr_r50_1x_coco as detr_r50_8x4_1x_coco in config

* reformat

* mask input_img_shape in img_meta as a general modification of base_detector forward_test

* reformat

* Supports for DETR hungarian matcher. (#3929)

* Add doc of modify loss (#3777)

* add doc of modify loss

* minor fix

* change name

* improve the function of simple_test_bboxes (#3853)

* update

* fix lint error

* add bbox_pred_split in sabl_head

* fix lint error

* fix yapf

* fix build error

* fix yapf

* Clean background_labels in the dense heads (#3221)

* Clean background_labels in the dense heads

* clean format

* Reformat

* Fix CI bug

* fix fsaf and the comments

* fix newly added heads

* fix yolact

* complete comments

* fix rpn transforming bug in two stage networks (#3754)

* fix rpn transforming bug in two_stage

* [Refactor] refactor get_subset_by_classes in dataloader for training with empty-GT images (#3695)

* Add regression test and test data

* Add fix for empty gt images

* Trigger CI build

* refactor get_subset_by_classes

* reformat and fix docstring

* [refactor]: move get_subset_by_classes to _filter_imgs

* make img_ids consistent

* resolve comments

* simplify logics

* add warning

* add warning

* add warning

Co-authored-by: mmeendez8 <miguelmndez@gmail.com>

* Fix nonzero in NMS for PyTorch 1.6.0 (#3867)

* Support TTA of ATSS, FCOS, YOLOv3 (#3844)

* Support TTA of ATSS, FCOS, YOLOv3

* Add comment

* [Docs] Fix typo in docs/tutorials/new_dataset.md (#3876)

* [Docs] Remove duplicate content in docs/config.md (#3875)

* [Enhance]: Convert mask to bool before using it as img's index for robustness and speedup (#3870)

* Convert mask to bool before using it as img's index

* lint

* Rewrite code in more concise way

* Fix typo in bbox_flip (#3886)

* fix the API change bug of PAA (#3883)

* fix cv2 import error of ligGL.so.1 (#3891)

* [enhance]: Improve documentation of modules and dataset customization (#3821)

* update tutorials for changing training settings

* update

* Update details of hook

* resolve comments

* reformat

* Update module documentations

* add notes for classes specification

* support to use pytorch 1.6 in docker (#3905)

* support to use pytorch 1.6 in docker

* update mmcv requirement

* update docs

* Add missing notes in data customization (#3906)

* [Fix]: fix mask rcnn training stuck problem when there is no positive rois (#3713)

* Fix mask rcnn stuck problem when there is no positive rois

* support non pos inference in cascade methods, link CU-49tawu

* print mmcv version in CI

* use mmcv repo to check wrappers

* change cpu build

* upgrade mmcv requirements and change ci back

* use pre-built whl in CI

* Bump to v2.5.0 (#3879)

* bump to v2.5.0

* update PR

* resolve comments

* clean unnecessary modification

* update bc breaking

* rephrase bc-breaking

* rephrase

* Added `generate_inputs_and_wrap_model` function for pytorch2onnx (#3857)

* added `generate_inputs_and_wrap_model` function for pytorch2onnx

* undo debugging changes

* added model.cpu().eval()

* refactored onnx

* fix verify

* move `generate_inputs_and_wrap_model` into mmdet.core.export

* use `generate_inputs_and_wrap_model` in tools/pytorch2onnx.py

* typo (#3917)

* Edit mmdet.core.export docstring (#3912)

* edit mmdet.core.export docstring

* update doctest

* fix small bugs

* supports for HungarianMatchAssigner, add bbox_cxcywh_to_xyxy and bbox_xyxy_to_cxcywh for bbox transform

* format box-wise related giou calculating as a function and implement it in iou2d_calculater.py

* supports for BboxGIoU2D and re-implements giou_loss using bbox_gious

* remove unnecessary

* reformat

* reformat docstring

* reformat

* rename

* supports for giou calculating in BboxOverlaps2D, and re-implements giou_loss using bbox_overlaps

* fix sabl validating bug in cascade_rcnn (#3913)

* reformat

* move giou related unit test from test_losses.py to test_iou2d_calculator.py

* reformat

* Avoid division by zero in PAA head when num_pos=0

* [Fix]: Avoid division by zero in PAA head when num_pos=0 (#3938)

* explicitly add mode in giou_loss

* Add supports for giou calculation in BboxOverlaps2D, and re-implements giou_loss using bbox_overlaps (#3936)

* supports for BboxGIoU2D and re-implements giou_loss using bbox_gious

* remove unnecessary

* reformat

* reformat docstring

* reformat

* rename

* supports for giou calculating in BboxOverlaps2D, and re-implements giou_loss using bbox_overlaps

* reformat

* move giou related unit test from test_losses.py to test_iou2d_calculator.py

* reformat

* Avoid division by zero in PAA head when num_pos=0

* explicitly add mode in giou_loss

* Add supports for giou calculation in BboxOverlaps2D, and add iou_calculator in hungarian_assigner

* rename hungarian_match_assigner as hungarian_assigner

* fix init

* reformat docstring

* Avoid division by zero in PAA head when num_pos=0

* fix cpu (#3948)

* add mode for iou_calculator and make giou cost as a default case

* make mode as a param in iou_calculator

* reformat docsting

* make iou_mode outside of iou_calculator

Co-authored-by: Cao Yuhang <yhcao6@gmail.com>
Co-authored-by: yuzhj <31239926+yuzhj@users.noreply.github.com>
Co-authored-by: Wenwei Zhang <40779233+ZwwWayne@users.noreply.github.com>
Co-authored-by: mmeendez8 <miguelmndez@gmail.com>
Co-authored-by: Yosuke Shinya <42844407+shinya7y@users.noreply.github.com>
Co-authored-by: LabMemNo003 <LabMemNo003@gmail.com>
Co-authored-by: Ye Liu <yeliudev@outlook.com>
Co-authored-by: aboettcher <aboettcher@users.noreply.github.com>
Co-authored-by: Ryan Li <xlide@connect.ust.hk>
Co-authored-by: Jiangmiao Pang <pangjiangmiao@gmail.com>

* Re-implements RandomCrop to support different crop_type (#4093)

* re-implements RandomCrop to support different crop_type

* add assertion for relative related crop_type

* reformat, and add image shape assertion for unit test

* reformat

* Supports for DETR training mode in process. (#3963)

* add input_img_shape in img_meta, and supports training mode toy

* toy commit

* toy commit

* re-organize and support for detr training mode

* add unit test for detr training, testing, and transformer_head

* add more unit test for transformer

* reformat

* remove unnecessary

* use small transformer model for unit test

* reformat docstring

* reformat

* reformat

* Supports DETR e150 config (#4197)

* rename e300 config as e150 config

* reformat

* add comments on override option in Resize

* add comments on override option in Resize

* position embeddingto positional encoding

* fix unit tests

* fix registry name bug

* rename file

* remove unnecessary

Co-authored-by: ZwwWayne <wayne.zw@outlook.com>
Co-authored-by: Cao Yuhang <yhcao6@gmail.com>
Co-authored-by: yuzhj <31239926+yuzhj@users.noreply.github.com>
Co-authored-by: Wenwei Zhang <40779233+ZwwWayne@users.noreply.github.com>
Co-authored-by: mmeendez8 <miguelmndez@gmail.com>
Co-authored-by: Yosuke Shinya <42844407+shinya7y@users.noreply.github.com>
Co-authored-by: LabMemNo003 <LabMemNo003@gmail.com>
Co-authored-by: Ye Liu <yeliudev@outlook.com>
Co-authored-by: aboettcher <aboettcher@users.noreply.github.com>
Co-authored-by: Ryan Li <xlide@connect.ust.hk>
Co-authored-by: Jiangmiao Pang <pangjiangmiao@gmail.com>