{"url":"/method/osa-identity-mapping-ese","slug":"osa-identity-mapping-ese","name":"OSA (identity mapping + eSE)","full_name":"OSA (identity mapping + eSE)","full_name_withheld":false,"description_markdown":"**One-Shot Aggregation with an Identity Mapping and eSE** is an image model block that extends [one-shot aggregation](https://paperswithcode.com/method/one-shot-aggregation) with a [residual connection](https://paperswithcode.com/method/residual-connection) and [effective squeeze-and-excitation block](https://paperswithcode.com/method/effective-squeeze-and-excitation-block). It is proposed as part of the [VoVNetV2](https://paperswithcode.com/method/vovnetv2) CNN architecture.\r\n\r\nThe module adds an identity mapping to the OSA module - the input path is connected to the end of an OSA module that is able to backpropagate the gradients of every OSA module in an end-to-end manner on each stage like a [ResNet](https://paperswithcode.com/method/resnet). Additionally, a [channel attention module](https://paperswithcode.com/method/channel-attention-module) - effective Squeeze-Excitation - is used which is like regular [squeeze-and-excitation](https://paperswithcode.com/method/squeeze-and-excitation-block) but uses only one FC layer with $C$ channels instead of two FCs without a channel dimension reduction, which maintains channel information.","description_state":"present","introduced_year":null,"introduced_by":{"title":"CenterMask : Real-Time Anchor-Free Instance Segmentation","paper":"/paper/centermask-real-time-anchor-free-instance-1","first_author":"Youngwan Lee","n_authors":2,"url_abs":null,"archive_paper_url":"https://paperswithcode.com/paper/centermask-real-time-anchor-free-instance-1"},"source":{"url":"https://arxiv.org/abs/1911.06667v6","title":"CenterMask : Real-Time Anchor-Free Instance Segmentation","url_on_a_paper_host":true},"code_snippet_url":"https://github.com/youngwanLEE/CenterMask/blob/72147e8aae673fcaf4103ee90a6a6b73863e7fa1/maskrcnn_benchmark/modeling/backbone/vovnet.py#L124","code_snippet_url_on_a_code_host":true,"categories":[{"area":"Computer Vision","area_id":"computer-vision","collection":"Image Model Blocks","url":"/methods/category/image-model-blocks","pwc_aliases":[]},{"area":"General","area_id":"general","collection":"Skip Connection Blocks","url":"/methods/category/skip-connection-blocks","pwc_aliases":[]}],"n_papers_tagged":1,"archive_num_papers":1,"papers_newest_first":[{"paper":"/paper/centermask-real-time-anchor-free-instance-1","title":"CenterMask : Real-Time Anchor-Free Instance Segmentation","date":"2019-11-15","arxiv_id":"1911.06667","n_code_links":8,"syntology":{"ran":1,"of":2,"unverified":1,"pointer_only":2}}],"papers_shown":1,"tasks":[{"task":"/task/instance-segmentation","name":"Instance Segmentation","papers":1},{"task":"/task/object-detection","name":"Object Detection","papers":1},{"task":"/task/panoptic-segmentation","name":"Panoptic Segmentation","papers":1},{"task":"/task/real-time-object-detection","name":"Real-Time Object Detection","papers":1},{"task":"/task/real-time-instance-segmentation","name":"Real-time Instance Segmentation","papers":1},{"task":"/task/segmentation","name":"Segmentation","papers":1},{"task":"/task/semantic-segmentation","name":"Semantic Segmentation","papers":1},{"task":"/task/semi-supervised-instance-segmentation","name":"Semi-Supervised Instance Segmentation","papers":1}],"tasks_shown":8,"n_tasks":8,"usage_by_year":[{"year":"2019","papers":1}],"row_source":"methods_table","archive":{"source":"pwc-archive (Hugging Face), CC BY-SA 4.0","snapshot":"2025-07-28","archive_url":"https://paperswithcode.com/method/osa-identity-mapping-ese"},"syntology_read_at":"2026-09-24T18:15:14+00:00"}