{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2019:USWKEH3HB5UT5IAHL6PBLWIZEK","short_pith_number":"pith:USWKEH3H","canonical_record":{"source":{"id":"1909.02466","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2019-09-05T14:57:53Z","cross_cats_sorted":["cs.LG"],"title_canon_sha256":"4cda2285050d27368e89b24bf00894f7b437ae2accadc2fd41c49ef2ec186e80","abstract_canon_sha256":"9e0382ecf2abc25f21be245ee672d750085784fc46fa6bb170c5f284273e9c68"},"schema_version":"1.0"},"canonical_sha256":"a4aca21f670f693ea0075f9e15d91922bc3d7ff277f6f15b2e37a463f570766b","source":{"kind":"arxiv","id":"1909.02466","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1909.02466","created_at":"2026-07-05T00:18:40Z"},{"alias_kind":"arxiv_version","alias_value":"1909.02466v2","created_at":"2026-07-05T00:18:40Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1909.02466","created_at":"2026-07-05T00:18:40Z"},{"alias_kind":"pith_short_12","alias_value":"USWKEH3HB5UT","created_at":"2026-07-05T00:18:40Z"},{"alias_kind":"pith_short_16","alias_value":"USWKEH3HB5UT5IAH","created_at":"2026-07-05T00:18:40Z"},{"alias_kind":"pith_short_8","alias_value":"USWKEH3H","created_at":"2026-07-05T00:18:40Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2019:USWKEH3HB5UT5IAHL6PBLWIZEK","target":"record","payload":{"canonical_record":{"source":{"id":"1909.02466","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2019-09-05T14:57:53Z","cross_cats_sorted":["cs.LG"],"title_canon_sha256":"4cda2285050d27368e89b24bf00894f7b437ae2accadc2fd41c49ef2ec186e80","abstract_canon_sha256":"9e0382ecf2abc25f21be245ee672d750085784fc46fa6bb170c5f284273e9c68"},"schema_version":"1.0"},"canonical_sha256":"a4aca21f670f693ea0075f9e15d91922bc3d7ff277f6f15b2e37a463f570766b","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T00:18:40.402808Z","signature_b64":"Cv2xnVgIQ4HJTg/20wkde0I8oB2QB+oOcQVtY7w9K9y3XdmJGQjyEHMPyB3jBmqilC5X8FJ8X9kYmitphHaLAw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"a4aca21f670f693ea0075f9e15d91922bc3d7ff277f6f15b2e37a463f570766b","last_reissued_at":"2026-07-05T00:18:40.402410Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T00:18:40.402410Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1909.02466","source_version":2,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T00:18:40Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"zrCzNvtvM2RetmHs5lACdL0xq2n6aXVWV0kMt7C0frGZJdYgjZluk/RDPadUGtLNspoBmq/p0jBdhK+jQl4sBQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-14T15:12:46.699796Z"},"content_sha256":"158803ae96e564cfeea48f584736919061a1ea920f5911b0df4ec0fd15a54fa1","schema_version":"1.0","event_id":"sha256:158803ae96e564cfeea48f584736919061a1ea920f5911b0df4ec0fd15a54fa1"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2019:USWKEH3HB5UT5IAHL6PBLWIZEK","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"FreeAnchor: Learning to Match Anchors for Visual Object Detection","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["cs.LG"],"primary_cat":"cs.CV","authors_text":"Chang Liu, Fang Wan, Qixiang Ye, Rongrong Ji, Xiaosong Zhang","submitted_at":"2019-09-05T14:57:53Z","abstract_excerpt":"Modern CNN-based object detectors assign anchors for ground-truth objects under the restriction of object-anchor Intersection-over-Unit (IoU). In this study, we propose a learning-to-match approach to break IoU restriction, allowing objects to match anchors in a flexible manner. Our approach, referred to as FreeAnchor, updates hand-crafted anchor assignment to \"free\" anchor matching by formulating detector training as a maximum likelihood estimation (MLE) procedure. FreeAnchor targets at learning features which best explain a class of objects in terms of both classification and localization. F"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1909.02466","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/1909.02466/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T00:18:40Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"HZx4U0uKMGrQYdo/fU3Q7KuB5dOnnimFVh1WR23Lri/pqYstZpBUFJQDozCNelvFumPFBoi8AJ1AFQ+S6KZ2Dw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-14T15:12:46.700861Z"},"content_sha256":"3e9e7a28b3d9d276c995490d1569f2378fc44e13e444dd5316ed5f22e41a2d73","schema_version":"1.0","event_id":"sha256:3e9e7a28b3d9d276c995490d1569f2378fc44e13e444dd5316ed5f22e41a2d73"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/USWKEH3HB5UT5IAHL6PBLWIZEK/bundle.json","state_url":"https://pith.science/pith/USWKEH3HB5UT5IAHL6PBLWIZEK/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/USWKEH3HB5UT5IAHL6PBLWIZEK/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-08-14T15:12:46Z","links":{"resolver":"https://pith.science/pith/USWKEH3HB5UT5IAHL6PBLWIZEK","bundle":"https://pith.science/pith/USWKEH3HB5UT5IAHL6PBLWIZEK/bundle.json","state":"https://pith.science/pith/USWKEH3HB5UT5IAHL6PBLWIZEK/state.json","well_known_bundle":"https://pith.science/.well-known/pith/USWKEH3HB5UT5IAHL6PBLWIZEK/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2019:USWKEH3HB5UT5IAHL6PBLWIZEK","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"9e0382ecf2abc25f21be245ee672d750085784fc46fa6bb170c5f284273e9c68","cross_cats_sorted":["cs.LG"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2019-09-05T14:57:53Z","title_canon_sha256":"4cda2285050d27368e89b24bf00894f7b437ae2accadc2fd41c49ef2ec186e80"},"schema_version":"1.0","source":{"id":"1909.02466","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1909.02466","created_at":"2026-07-05T00:18:40Z"},{"alias_kind":"arxiv_version","alias_value":"1909.02466v2","created_at":"2026-07-05T00:18:40Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1909.02466","created_at":"2026-07-05T00:18:40Z"},{"alias_kind":"pith_short_12","alias_value":"USWKEH3HB5UT","created_at":"2026-07-05T00:18:40Z"},{"alias_kind":"pith_short_16","alias_value":"USWKEH3HB5UT5IAH","created_at":"2026-07-05T00:18:40Z"},{"alias_kind":"pith_short_8","alias_value":"USWKEH3H","created_at":"2026-07-05T00:18:40Z"}],"graph_snapshots":[{"event_id":"sha256:3e9e7a28b3d9d276c995490d1569f2378fc44e13e444dd5316ed5f22e41a2d73","target":"graph","created_at":"2026-07-05T00:18:40Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/1909.02466/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Modern CNN-based object detectors assign anchors for ground-truth objects under the restriction of object-anchor Intersection-over-Unit (IoU). In this study, we propose a learning-to-match approach to break IoU restriction, allowing objects to match anchors in a flexible manner. Our approach, referred to as FreeAnchor, updates hand-crafted anchor assignment to \"free\" anchor matching by formulating detector training as a maximum likelihood estimation (MLE) procedure. FreeAnchor targets at learning features which best explain a class of objects in terms of both classification and localization. F","authors_text":"Chang Liu, Fang Wan, Qixiang Ye, Rongrong Ji, Xiaosong Zhang","cross_cats":["cs.LG"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2019-09-05T14:57:53Z","title":"FreeAnchor: Learning to Match Anchors for Visual Object Detection"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1909.02466","kind":"arxiv","version":2},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:158803ae96e564cfeea48f584736919061a1ea920f5911b0df4ec0fd15a54fa1","target":"record","created_at":"2026-07-05T00:18:40Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"9e0382ecf2abc25f21be245ee672d750085784fc46fa6bb170c5f284273e9c68","cross_cats_sorted":["cs.LG"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2019-09-05T14:57:53Z","title_canon_sha256":"4cda2285050d27368e89b24bf00894f7b437ae2accadc2fd41c49ef2ec186e80"},"schema_version":"1.0","source":{"id":"1909.02466","kind":"arxiv","version":2}},"canonical_sha256":"a4aca21f670f693ea0075f9e15d91922bc3d7ff277f6f15b2e37a463f570766b","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"a4aca21f670f693ea0075f9e15d91922bc3d7ff277f6f15b2e37a463f570766b","first_computed_at":"2026-07-05T00:18:40.402410Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T00:18:40.402410Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"Cv2xnVgIQ4HJTg/20wkde0I8oB2QB+oOcQVtY7w9K9y3XdmJGQjyEHMPyB3jBmqilC5X8FJ8X9kYmitphHaLAw==","signature_status":"signed_v1","signed_at":"2026-07-05T00:18:40.402808Z","signed_message":"canonical_sha256_bytes"},"source_id":"1909.02466","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:158803ae96e564cfeea48f584736919061a1ea920f5911b0df4ec0fd15a54fa1","sha256:3e9e7a28b3d9d276c995490d1569f2378fc44e13e444dd5316ed5f22e41a2d73"],"state_sha256":"5a7c9799ac4f665ae66ddb4f1ac1630d1c0a9cba9e43429a6f86ebbf45b590cb"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"JuFDT3b1xDC3G8oB5cbsmvpjMqg3VVUbll5iXAEmFkfKtW4eaXUQfR3G82d9EnvgYjdce0F8HOjlq5jJgLXeAg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-14T15:12:46.708344Z","bundle_sha256":"2e20e8a750fd92ce119c81b2abb3b4958d2f77d4276e2330ee45e348d8f7cdb6"}}