plugin/detectionLayerPlugin/README.md
This plugin is deprecated since TensorRT 10.12 and will be removed in a future release. No alternatives are planned to be provided.
Table Of Contents
The DetectionLayer plugin performs bounding boxes refinement of MaskRCNN's detection head and generate the final detection output of MaskRCNN. It is used in sampleMaskRCNN.
This plugin supports the NCHW format. It takes three input tensors: delta_bbox, score and roi
delta_bbox is the refinement information of roi boxes generated from ProposalLayer. delta_bbox tensor's shape is [N, rois, num_classes*4, 1, 1] where N is batch size,
rois is the total number of ROI boxes candidates per image, and num_classes*4 means 4 refinement elements ([dy, dx, dh, dw]) for each roi box as different classes.
score is the predicted class scores of ROI boxes generated from ProposalLayer of shape [N, rois, num_classes, 1, 1]. There is argmaxoperation in Detectionlayer to determine the final class of detection
candidates.
roi is the coordinates of ROI boxes candidates from ProposalLayer of shape [N, rois, 4].
This plugin generates output of shape [N, keep_topk, 6] where keep_topk is the maximum number of detections left after NMS and '6' means 6 elements of an detection [y1, x1, y2, x2, class_label, score]
This plugin has the plugin creator class DetectionlayerPluginCreator and the plugin class Detectionlayer.
The following parameters were used to create Detectionlayer instance:
| Type | Parameter | Description |
|---|---|---|
int | num_classes | Number of detection classes(including background). num_classes=81 for COCO dataset |
int | keep_topk | Number of detections will be kept after NMS. |
float | score_threshold | Confidence threshold value. This plugin will drop a detection if its class confidence(score) is under "score_threshold". |
float | iou_threshold | IOU threshold value used in NMS. |
The number of anchors is capped at 1024 to support embedded devices with smaller shared memory capacity.
To enable support for a device with higher memory, calls to sortPerClass, PerClassNMS and KeepTopKGather can be modified in RefineBatchClassNMS (maskRCNNKernels.cu).
The following resources provide a deeper understanding of the Detectionlayer plugin:
For terms and conditions for use, reproduction, and distribution, see the TensorRT Software License Agreement documentation.
May 2025 Add deprecation note.
January 2022: The Limitations section was added to this README.md file to document limitations of the plugin related to the maximum number of anchors it can support.
June 2019: First release of this README.md file.
There are no known issues in this plugin.