{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2022:W7XOKPRC36DVCNSAIAJLGNC572","short_pith_number":"pith:W7XOKPRC","canonical_record":{"source":{"id":"2210.05635","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2022-10-11T17:28:10Z","cross_cats_sorted":[],"title_canon_sha256":"929ab08737c56b863147d3ed096101721148d4b7cf8d1f9360dbc035ab1f6be3","abstract_canon_sha256":"e70026a93bec025a938addeb9eae5c9497e140b9de0ec82214d7dd8e64032af4"},"schema_version":"1.0"},"canonical_sha256":"b7eee53e22df875136404012b3345dfeadd36324a070e44f42b4fe02b57e469e","source":{"kind":"arxiv","id":"2210.05635","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2210.05635","created_at":"2026-07-05T05:06:34Z"},{"alias_kind":"arxiv_version","alias_value":"2210.05635v2","created_at":"2026-07-05T05:06:34Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2210.05635","created_at":"2026-07-05T05:06:34Z"},{"alias_kind":"pith_short_12","alias_value":"W7XOKPRC36DV","created_at":"2026-07-05T05:06:34Z"},{"alias_kind":"pith_short_16","alias_value":"W7XOKPRC36DVCNSA","created_at":"2026-07-05T05:06:34Z"},{"alias_kind":"pith_short_8","alias_value":"W7XOKPRC","created_at":"2026-07-05T05:06:34Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2022:W7XOKPRC36DVCNSAIAJLGNC572","target":"record","payload":{"canonical_record":{"source":{"id":"2210.05635","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2022-10-11T17:28:10Z","cross_cats_sorted":[],"title_canon_sha256":"929ab08737c56b863147d3ed096101721148d4b7cf8d1f9360dbc035ab1f6be3","abstract_canon_sha256":"e70026a93bec025a938addeb9eae5c9497e140b9de0ec82214d7dd8e64032af4"},"schema_version":"1.0"},"canonical_sha256":"b7eee53e22df875136404012b3345dfeadd36324a070e44f42b4fe02b57e469e","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T05:06:34.862905Z","signature_b64":"tKi+KkgbNw3IrjGO48KdrtgE9CN9mI8iNACwj5A6t0DtrarCzOgMZSTtLA6rDLoO6L+HbffCMRHse7LLW+rJAg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"b7eee53e22df875136404012b3345dfeadd36324a070e44f42b4fe02b57e469e","last_reissued_at":"2026-07-05T05:06:34.862532Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T05:06:34.862532Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2210.05635","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":"2026-07-05T05:06:34Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"VvXiedgHkhaxs05H5ZCBROo8G6CSNh+M81IcDa0rgbDG6vH+lDxaKcRRAGUKWbiplgXF6tvhYsSpLwPl4JCVCQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-06T18:44:28.660133Z"},"content_sha256":"f177df540b8a17b6110712262db9f00a961e1bdf19f78d01b5f831a488667f12","schema_version":"1.0","event_id":"sha256:f177df540b8a17b6110712262db9f00a961e1bdf19f78d01b5f831a488667f12"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2022:W7XOKPRC36DVCNSAIAJLGNC572","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Oflib: Facilitating Operations with and on Optical Flow Fields in Python","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cs.CV","authors_text":"Christos Bergeles, Claudio Ravasio, Lyndon da Cruz","submitted_at":"2022-10-11T17:28:10Z","abstract_excerpt":"We present a robust theoretical framework for the characterisation and manipulation of optical flow, i.e 2D vector fields, in the context of their use in motion estimation algorithms and beyond. The definition of two frames of reference guides the mathematical derivation of flow field application, inversion, evaluation, and composition operations. This structured approach is then used as the foundation for an implementation in Python 3, with the fully differentiable PyTorch version oflibpytorch supporting back-propagation as required for deep learning. We verify the flow composition method emp"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2210.05635","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/2210.05635/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":"2026-07-05T05:06:34Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"bZc4UdZVsblElJVWfSyaAgFZa3jW3Ya3OTizPJ7OW+TB5fKKq0+dBWzYiXiSTTz/VkGHh86up4/T79BXZDPiDg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-06T18:44:28.660514Z"},"content_sha256":"f4a123ca1ed3d88f040692ebdefb89bab9590d1bacc8b45392fe03a64edbcf8a","schema_version":"1.0","event_id":"sha256:f4a123ca1ed3d88f040692ebdefb89bab9590d1bacc8b45392fe03a64edbcf8a"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/W7XOKPRC36DVCNSAIAJLGNC572/bundle.json","state_url":"https://pith.science/pith/W7XOKPRC36DVCNSAIAJLGNC572/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/W7XOKPRC36DVCNSAIAJLGNC572/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":"2026-07-06T18:44:28Z","links":{"resolver":"https://pith.science/pith/W7XOKPRC36DVCNSAIAJLGNC572","bundle":"https://pith.science/pith/W7XOKPRC36DVCNSAIAJLGNC572/bundle.json","state":"https://pith.science/pith/W7XOKPRC36DVCNSAIAJLGNC572/state.json","well_known_bundle":"https://pith.science/.well-known/pith/W7XOKPRC36DVCNSAIAJLGNC572/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2022:W7XOKPRC36DVCNSAIAJLGNC572","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":"e70026a93bec025a938addeb9eae5c9497e140b9de0ec82214d7dd8e64032af4","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2022-10-11T17:28:10Z","title_canon_sha256":"929ab08737c56b863147d3ed096101721148d4b7cf8d1f9360dbc035ab1f6be3"},"schema_version":"1.0","source":{"id":"2210.05635","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2210.05635","created_at":"2026-07-05T05:06:34Z"},{"alias_kind":"arxiv_version","alias_value":"2210.05635v2","created_at":"2026-07-05T05:06:34Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2210.05635","created_at":"2026-07-05T05:06:34Z"},{"alias_kind":"pith_short_12","alias_value":"W7XOKPRC36DV","created_at":"2026-07-05T05:06:34Z"},{"alias_kind":"pith_short_16","alias_value":"W7XOKPRC36DVCNSA","created_at":"2026-07-05T05:06:34Z"},{"alias_kind":"pith_short_8","alias_value":"W7XOKPRC","created_at":"2026-07-05T05:06:34Z"}],"graph_snapshots":[{"event_id":"sha256:f4a123ca1ed3d88f040692ebdefb89bab9590d1bacc8b45392fe03a64edbcf8a","target":"graph","created_at":"2026-07-05T05:06:34Z","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/2210.05635/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"We present a robust theoretical framework for the characterisation and manipulation of optical flow, i.e 2D vector fields, in the context of their use in motion estimation algorithms and beyond. The definition of two frames of reference guides the mathematical derivation of flow field application, inversion, evaluation, and composition operations. This structured approach is then used as the foundation for an implementation in Python 3, with the fully differentiable PyTorch version oflibpytorch supporting back-propagation as required for deep learning. We verify the flow composition method emp","authors_text":"Christos Bergeles, Claudio Ravasio, Lyndon da Cruz","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2022-10-11T17:28:10Z","title":"Oflib: Facilitating Operations with and on Optical Flow Fields in Python"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2210.05635","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:f177df540b8a17b6110712262db9f00a961e1bdf19f78d01b5f831a488667f12","target":"record","created_at":"2026-07-05T05:06:34Z","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":"e70026a93bec025a938addeb9eae5c9497e140b9de0ec82214d7dd8e64032af4","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2022-10-11T17:28:10Z","title_canon_sha256":"929ab08737c56b863147d3ed096101721148d4b7cf8d1f9360dbc035ab1f6be3"},"schema_version":"1.0","source":{"id":"2210.05635","kind":"arxiv","version":2}},"canonical_sha256":"b7eee53e22df875136404012b3345dfeadd36324a070e44f42b4fe02b57e469e","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"b7eee53e22df875136404012b3345dfeadd36324a070e44f42b4fe02b57e469e","first_computed_at":"2026-07-05T05:06:34.862532Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T05:06:34.862532Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"tKi+KkgbNw3IrjGO48KdrtgE9CN9mI8iNACwj5A6t0DtrarCzOgMZSTtLA6rDLoO6L+HbffCMRHse7LLW+rJAg==","signature_status":"signed_v1","signed_at":"2026-07-05T05:06:34.862905Z","signed_message":"canonical_sha256_bytes"},"source_id":"2210.05635","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:f177df540b8a17b6110712262db9f00a961e1bdf19f78d01b5f831a488667f12","sha256:f4a123ca1ed3d88f040692ebdefb89bab9590d1bacc8b45392fe03a64edbcf8a"],"state_sha256":"0741b3558df8901ff96a769fea683d3bb118b3d9039119c7188aac21b6ff9b06"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"BfuzmCwitekzbowyA7SJpPCWIqvWN+BiXZ97tAFY76HCbIrwy2sPqyXkLI/ESEu4CpFQlpUQWJbIOb9Ttc3RDw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-07-06T18:44:28.662389Z","bundle_sha256":"58a0589b786181b1aea6ba387d9b2056744adde70132849271c837cffeb51545"}}