{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2021:EP7MAV6YIF7RFVC6CKIFIOXATM","short_pith_number":"pith:EP7MAV6Y","canonical_record":{"source":{"id":"2112.12002","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2021-12-22T16:27:11Z","cross_cats_sorted":[],"title_canon_sha256":"b918304ca87f4cca5bf9bed0c4cac636449344c17694d2d413c306d6e8374f01","abstract_canon_sha256":"c053135b14a0dddd0216aa69efe9eb9bc388f6c5fc3870cc7f11b214f4d32b25"},"schema_version":"1.0"},"canonical_sha256":"23fec057d8417f12d45e1290543ae09b00124d8ea85e02aa3d24c0d60a109a51","source":{"kind":"arxiv","id":"2112.12002","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2112.12002","created_at":"2026-07-05T04:38:46Z"},{"alias_kind":"arxiv_version","alias_value":"2112.12002v2","created_at":"2026-07-05T04:38:46Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2112.12002","created_at":"2026-07-05T04:38:46Z"},{"alias_kind":"pith_short_12","alias_value":"EP7MAV6YIF7R","created_at":"2026-07-05T04:38:46Z"},{"alias_kind":"pith_short_16","alias_value":"EP7MAV6YIF7RFVC6","created_at":"2026-07-05T04:38:46Z"},{"alias_kind":"pith_short_8","alias_value":"EP7MAV6Y","created_at":"2026-07-05T04:38:46Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2021:EP7MAV6YIF7RFVC6CKIFIOXATM","target":"record","payload":{"canonical_record":{"source":{"id":"2112.12002","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2021-12-22T16:27:11Z","cross_cats_sorted":[],"title_canon_sha256":"b918304ca87f4cca5bf9bed0c4cac636449344c17694d2d413c306d6e8374f01","abstract_canon_sha256":"c053135b14a0dddd0216aa69efe9eb9bc388f6c5fc3870cc7f11b214f4d32b25"},"schema_version":"1.0"},"canonical_sha256":"23fec057d8417f12d45e1290543ae09b00124d8ea85e02aa3d24c0d60a109a51","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T04:38:46.874958Z","signature_b64":"3lsaIft+vS9K59mwouoHZwheN5KaX8LUWjNHLv2367G0Bdz3wpv+jGhGkb3Y//lPbqBjsCKXOLabQLcg/sbxAg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"23fec057d8417f12d45e1290543ae09b00124d8ea85e02aa3d24c0d60a109a51","last_reissued_at":"2026-07-05T04:38:46.874540Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T04:38:46.874540Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2112.12002","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":"2026-07-05T04:38:46Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"tr/XE1dYlxumUNpbZkXsMT7F00Xtb8XfWtS8FR0jK1OVMPD6Eifs1aVqpMDUQ4yyDfx4b9F0bVrAKn94ASKTBg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-10T09:49:08.144220Z"},"content_sha256":"474392485e70bf3c429c18d7f2319827dd7da8841af0fb37eb8c1b024c424dda","schema_version":"1.0","event_id":"sha256:474392485e70bf3c429c18d7f2319827dd7da8841af0fb37eb8c1b024c424dda"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2021:EP7MAV6YIF7RFVC6CKIFIOXATM","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Looking Beyond Corners: Contrastive Learning of Visual Representations for Keypoint Detection and Description Extraction","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cs.CV","authors_text":"Henrique Siqueira, Ibrahim Halfaoui, Markus Karmann, Onay Urfalioglu, Patrick Ruhkamp","submitted_at":"2021-12-22T16:27:11Z","abstract_excerpt":"Learnable keypoint detectors and descriptors are beginning to outperform classical hand-crafted feature extraction methods. Recent studies on self-supervised learning of visual representations have driven the increasing performance of learnable models based on deep networks. By leveraging traditional data augmentations and homography transformations, these networks learn to detect corners under adverse conditions such as extreme illumination changes. However, their generalization capabilities are limited to corner-like features detected a priori by classical methods or synthetically generated "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2112.12002","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/2112.12002/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":"2026-07-05T04:38:46Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"h37gxILjAY16XiRY3oPsE5V8EnP51hlHBG0b8aDUOMtayXOUNfbkOMHFe9e8kcDClvqgqq8ltz9aTZe3hg2RDw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-10T09:49:08.144615Z"},"content_sha256":"ce1940c4e6484f308bf56d332fa0710efaf329f313a42d3bc5b5c1ddd7d38b95","schema_version":"1.0","event_id":"sha256:ce1940c4e6484f308bf56d332fa0710efaf329f313a42d3bc5b5c1ddd7d38b95"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/EP7MAV6YIF7RFVC6CKIFIOXATM/bundle.json","state_url":"https://pith.science/pith/EP7MAV6YIF7RFVC6CKIFIOXATM/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/EP7MAV6YIF7RFVC6CKIFIOXATM/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":"2026-07-10T09:49:08Z","links":{"resolver":"https://pith.science/pith/EP7MAV6YIF7RFVC6CKIFIOXATM","bundle":"https://pith.science/pith/EP7MAV6YIF7RFVC6CKIFIOXATM/bundle.json","state":"https://pith.science/pith/EP7MAV6YIF7RFVC6CKIFIOXATM/state.json","well_known_bundle":"https://pith.science/.well-known/pith/EP7MAV6YIF7RFVC6CKIFIOXATM/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2021:EP7MAV6YIF7RFVC6CKIFIOXATM","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":"c053135b14a0dddd0216aa69efe9eb9bc388f6c5fc3870cc7f11b214f4d32b25","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2021-12-22T16:27:11Z","title_canon_sha256":"b918304ca87f4cca5bf9bed0c4cac636449344c17694d2d413c306d6e8374f01"},"schema_version":"1.0","source":{"id":"2112.12002","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2112.12002","created_at":"2026-07-05T04:38:46Z"},{"alias_kind":"arxiv_version","alias_value":"2112.12002v2","created_at":"2026-07-05T04:38:46Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2112.12002","created_at":"2026-07-05T04:38:46Z"},{"alias_kind":"pith_short_12","alias_value":"EP7MAV6YIF7R","created_at":"2026-07-05T04:38:46Z"},{"alias_kind":"pith_short_16","alias_value":"EP7MAV6YIF7RFVC6","created_at":"2026-07-05T04:38:46Z"},{"alias_kind":"pith_short_8","alias_value":"EP7MAV6Y","created_at":"2026-07-05T04:38:46Z"}],"graph_snapshots":[{"event_id":"sha256:ce1940c4e6484f308bf56d332fa0710efaf329f313a42d3bc5b5c1ddd7d38b95","target":"graph","created_at":"2026-07-05T04:38:46Z","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/2112.12002/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Learnable keypoint detectors and descriptors are beginning to outperform classical hand-crafted feature extraction methods. Recent studies on self-supervised learning of visual representations have driven the increasing performance of learnable models based on deep networks. By leveraging traditional data augmentations and homography transformations, these networks learn to detect corners under adverse conditions such as extreme illumination changes. However, their generalization capabilities are limited to corner-like features detected a priori by classical methods or synthetically generated ","authors_text":"Henrique Siqueira, Ibrahim Halfaoui, Markus Karmann, Onay Urfalioglu, Patrick Ruhkamp","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2021-12-22T16:27:11Z","title":"Looking Beyond Corners: Contrastive Learning of Visual Representations for Keypoint Detection and Description Extraction"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2112.12002","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":"sha256:474392485e70bf3c429c18d7f2319827dd7da8841af0fb37eb8c1b024c424dda","target":"record","created_at":"2026-07-05T04:38:46Z","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":"c053135b14a0dddd0216aa69efe9eb9bc388f6c5fc3870cc7f11b214f4d32b25","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2021-12-22T16:27:11Z","title_canon_sha256":"b918304ca87f4cca5bf9bed0c4cac636449344c17694d2d413c306d6e8374f01"},"schema_version":"1.0","source":{"id":"2112.12002","kind":"arxiv","version":2}},"canonical_sha256":"23fec057d8417f12d45e1290543ae09b00124d8ea85e02aa3d24c0d60a109a51","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"23fec057d8417f12d45e1290543ae09b00124d8ea85e02aa3d24c0d60a109a51","first_computed_at":"2026-07-05T04:38:46.874540Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T04:38:46.874540Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"3lsaIft+vS9K59mwouoHZwheN5KaX8LUWjNHLv2367G0Bdz3wpv+jGhGkb3Y//lPbqBjsCKXOLabQLcg/sbxAg==","signature_status":"signed_v1","signed_at":"2026-07-05T04:38:46.874958Z","signed_message":"canonical_sha256_bytes"},"source_id":"2112.12002","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:474392485e70bf3c429c18d7f2319827dd7da8841af0fb37eb8c1b024c424dda","sha256:ce1940c4e6484f308bf56d332fa0710efaf329f313a42d3bc5b5c1ddd7d38b95"],"state_sha256":"b624da8e1c6f20df8703a9d8d8a7a026c621408a694651df445708b4b82a7d0c"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"11aBbpuhORgEZunA1WTG5H7hByEYjeSF9b1YPQFez6YSLyriQkaio2W0r6OsfkojcEdA4wYhx3OfuApApCcfBw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-07-10T09:49:08.146583Z","bundle_sha256":"f6ef4a249075060a60b7eeb5088019cbb12e55e9187f8571ae8271a8086ee70b"}}