{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2018:AQI7HHXQNH3E3WTVDVYZD7YQF2","short_pith_number":"pith:AQI7HHXQ","canonical_record":{"source":{"id":"1812.08277","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2018-12-19T22:36:57Z","cross_cats_sorted":["cs.DS","math.OC"],"title_canon_sha256":"1106bae34c053f4687bcf17ebfda3f808e468f22e54a7115d9b68d9c4860c19b","abstract_canon_sha256":"6a626ee8169716047ab80e93fe029b943455f1599b1feeb9e94658f4c9423c85"},"schema_version":"1.0"},"canonical_sha256":"0411f39ef069f64dda751d7191ff102ebdbbe2e61c6f714368b224dc9de49eae","source":{"kind":"arxiv","id":"1812.08277","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1812.08277","created_at":"2026-05-17T23:44:37Z"},{"alias_kind":"arxiv_version","alias_value":"1812.08277v2","created_at":"2026-05-17T23:44:37Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1812.08277","created_at":"2026-05-17T23:44:37Z"},{"alias_kind":"pith_short_12","alias_value":"AQI7HHXQNH3E","created_at":"2026-05-18T12:32:13Z"},{"alias_kind":"pith_short_16","alias_value":"AQI7HHXQNH3E3WTV","created_at":"2026-05-18T12:32:13Z"},{"alias_kind":"pith_short_8","alias_value":"AQI7HHXQ","created_at":"2026-05-18T12:32:13Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2018:AQI7HHXQNH3E3WTVDVYZD7YQF2","target":"record","payload":{"canonical_record":{"source":{"id":"1812.08277","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2018-12-19T22:36:57Z","cross_cats_sorted":["cs.DS","math.OC"],"title_canon_sha256":"1106bae34c053f4687bcf17ebfda3f808e468f22e54a7115d9b68d9c4860c19b","abstract_canon_sha256":"6a626ee8169716047ab80e93fe029b943455f1599b1feeb9e94658f4c9423c85"},"schema_version":"1.0"},"canonical_sha256":"0411f39ef069f64dda751d7191ff102ebdbbe2e61c6f714368b224dc9de49eae","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:44:37.847089Z","signature_b64":"U1Pm9VVO7+wbP7fYhfHEHx0qXml6gMIDhUMd/rMpdb+IoDu+Un/4ohzy1Nl7JPPHTzxR8CuQ+UB0+Bfk5ivnAQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"0411f39ef069f64dda751d7191ff102ebdbbe2e61c6f714368b224dc9de49eae","last_reissued_at":"2026-05-17T23:44:37.846587Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:44:37.846587Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1812.08277","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":"2026-05-17T23:44:37Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"VfoOUG+ZFF5JgUmVhsunF67OVfZY/pFEX8duhaQgVskJOblfHykOKAV0sNW/Q8FMhxTwKJ5TZXLxlPZ2nKOeBg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-10T17:18:59.194507Z"},"content_sha256":"ce8d868ac033f2115a24949756eb097540d97e25ea99d8b79f3029851e3a34b5","schema_version":"1.0","event_id":"sha256:ce8d868ac033f2115a24949756eb097540d97e25ea99d8b79f3029851e3a34b5"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2018:AQI7HHXQNH3E3WTVDVYZD7YQF2","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Two-Dimensional Phase Unwrapping via Balanced Spanning Forests","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["cs.DS","math.OC"],"primary_cat":"eess.SP","authors_text":"Ian Herszterg, Marcus Poggi, Thibaut Vidal","submitted_at":"2018-12-19T22:36:57Z","abstract_excerpt":"Phase unwrapping is the process of recovering a continuous phase signal from an original signal wrapped in the ($-\\pi$,$\\pi$] interval. It is a critical step of coherent signal processing, with applications such as synthetic aperture radar, acoustic imaging, magnetic resonance, X-ray crystallography, and seismic processing. In the field of computational optics, this problem is classically treated as a norm-minimization problem, in which one seeks to minimize the differences between the gradients of the original wrapped signal and those of the continuous unwrapped signal. When the L0-norm is co"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1812.08277","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":""},"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":"2026-05-17T23:44:37Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Y6WoWEqskd68ZsuTG8dio6hIMzkNMbn4Q5XyxLNcS6ehb1InVJG1n5g//EVtrD4icuWDcOAVST3prGR29A2kDw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-10T17:18:59.195224Z"},"content_sha256":"9532aeffe88f44e1cb389fd2d48031aad152a25174eb070b1328d6f22348bc99","schema_version":"1.0","event_id":"sha256:9532aeffe88f44e1cb389fd2d48031aad152a25174eb070b1328d6f22348bc99"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/AQI7HHXQNH3E3WTVDVYZD7YQF2/bundle.json","state_url":"https://pith.science/pith/AQI7HHXQNH3E3WTVDVYZD7YQF2/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/AQI7HHXQNH3E3WTVDVYZD7YQF2/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":"2026-06-10T17:18:59Z","links":{"resolver":"https://pith.science/pith/AQI7HHXQNH3E3WTVDVYZD7YQF2","bundle":"https://pith.science/pith/AQI7HHXQNH3E3WTVDVYZD7YQF2/bundle.json","state":"https://pith.science/pith/AQI7HHXQNH3E3WTVDVYZD7YQF2/state.json","well_known_bundle":"https://pith.science/.well-known/pith/AQI7HHXQNH3E3WTVDVYZD7YQF2/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:AQI7HHXQNH3E3WTVDVYZD7YQF2","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":"6a626ee8169716047ab80e93fe029b943455f1599b1feeb9e94658f4c9423c85","cross_cats_sorted":["cs.DS","math.OC"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2018-12-19T22:36:57Z","title_canon_sha256":"1106bae34c053f4687bcf17ebfda3f808e468f22e54a7115d9b68d9c4860c19b"},"schema_version":"1.0","source":{"id":"1812.08277","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1812.08277","created_at":"2026-05-17T23:44:37Z"},{"alias_kind":"arxiv_version","alias_value":"1812.08277v2","created_at":"2026-05-17T23:44:37Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1812.08277","created_at":"2026-05-17T23:44:37Z"},{"alias_kind":"pith_short_12","alias_value":"AQI7HHXQNH3E","created_at":"2026-05-18T12:32:13Z"},{"alias_kind":"pith_short_16","alias_value":"AQI7HHXQNH3E3WTV","created_at":"2026-05-18T12:32:13Z"},{"alias_kind":"pith_short_8","alias_value":"AQI7HHXQ","created_at":"2026-05-18T12:32:13Z"}],"graph_snapshots":[{"event_id":"sha256:9532aeffe88f44e1cb389fd2d48031aad152a25174eb070b1328d6f22348bc99","target":"graph","created_at":"2026-05-17T23:44:37Z","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"},"paper":{"abstract_excerpt":"Phase unwrapping is the process of recovering a continuous phase signal from an original signal wrapped in the ($-\\pi$,$\\pi$] interval. It is a critical step of coherent signal processing, with applications such as synthetic aperture radar, acoustic imaging, magnetic resonance, X-ray crystallography, and seismic processing. In the field of computational optics, this problem is classically treated as a norm-minimization problem, in which one seeks to minimize the differences between the gradients of the original wrapped signal and those of the continuous unwrapped signal. When the L0-norm is co","authors_text":"Ian Herszterg, Marcus Poggi, Thibaut Vidal","cross_cats":["cs.DS","math.OC"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2018-12-19T22:36:57Z","title":"Two-Dimensional Phase Unwrapping via Balanced Spanning Forests"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1812.08277","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:ce8d868ac033f2115a24949756eb097540d97e25ea99d8b79f3029851e3a34b5","target":"record","created_at":"2026-05-17T23:44:37Z","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":"6a626ee8169716047ab80e93fe029b943455f1599b1feeb9e94658f4c9423c85","cross_cats_sorted":["cs.DS","math.OC"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2018-12-19T22:36:57Z","title_canon_sha256":"1106bae34c053f4687bcf17ebfda3f808e468f22e54a7115d9b68d9c4860c19b"},"schema_version":"1.0","source":{"id":"1812.08277","kind":"arxiv","version":2}},"canonical_sha256":"0411f39ef069f64dda751d7191ff102ebdbbe2e61c6f714368b224dc9de49eae","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"0411f39ef069f64dda751d7191ff102ebdbbe2e61c6f714368b224dc9de49eae","first_computed_at":"2026-05-17T23:44:37.846587Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:44:37.846587Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"U1Pm9VVO7+wbP7fYhfHEHx0qXml6gMIDhUMd/rMpdb+IoDu+Un/4ohzy1Nl7JPPHTzxR8CuQ+UB0+Bfk5ivnAQ==","signature_status":"signed_v1","signed_at":"2026-05-17T23:44:37.847089Z","signed_message":"canonical_sha256_bytes"},"source_id":"1812.08277","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:ce8d868ac033f2115a24949756eb097540d97e25ea99d8b79f3029851e3a34b5","sha256:9532aeffe88f44e1cb389fd2d48031aad152a25174eb070b1328d6f22348bc99"],"state_sha256":"8fc15bcdd1d3ad6dfe8d5a60ecd687f84ae577f9b0cf85b51579a5d6fd393045"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"1nnE3M/t4q3pWT/DRoPXFOyYdiuK675WLa8iJ01M1X47Z0QcNfnVjy+yRJgTw4JyG2iP9lLceB0vXmRkv1N4CQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-10T17:18:59.199746Z","bundle_sha256":"56f5b836d6fa16d20aff0c396fe5066c0db703e81c9d5789924693056e7eac38"}}