{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2014:7MLM2WJEOF76OJK2DXKAKUV6OP","short_pith_number":"pith:7MLM2WJE","canonical_record":{"source":{"id":"1411.6267","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2014-11-23T16:57:12Z","cross_cats_sorted":[],"title_canon_sha256":"c160762668c09906d2e18216a3f0c6d17220064038ad36d6c3e379733466eed1","abstract_canon_sha256":"4faec8118df3db2c22b6d6be8743474c5970f00c55f4763a563e5e4344523a6e"},"schema_version":"1.0"},"canonical_sha256":"fb16cd5924717fe7255a1dd40552be73f4e04b56839670fb76cc29dcc3d3698a","source":{"kind":"arxiv","id":"1411.6267","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1411.6267","created_at":"2026-05-18T02:31:03Z"},{"alias_kind":"arxiv_version","alias_value":"1411.6267v1","created_at":"2026-05-18T02:31:03Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1411.6267","created_at":"2026-05-18T02:31:03Z"},{"alias_kind":"pith_short_12","alias_value":"7MLM2WJEOF76","created_at":"2026-05-18T12:28:19Z"},{"alias_kind":"pith_short_16","alias_value":"7MLM2WJEOF76OJK2","created_at":"2026-05-18T12:28:19Z"},{"alias_kind":"pith_short_8","alias_value":"7MLM2WJE","created_at":"2026-05-18T12:28:19Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2014:7MLM2WJEOF76OJK2DXKAKUV6OP","target":"record","payload":{"canonical_record":{"source":{"id":"1411.6267","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2014-11-23T16:57:12Z","cross_cats_sorted":[],"title_canon_sha256":"c160762668c09906d2e18216a3f0c6d17220064038ad36d6c3e379733466eed1","abstract_canon_sha256":"4faec8118df3db2c22b6d6be8743474c5970f00c55f4763a563e5e4344523a6e"},"schema_version":"1.0"},"canonical_sha256":"fb16cd5924717fe7255a1dd40552be73f4e04b56839670fb76cc29dcc3d3698a","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:31:03.610161Z","signature_b64":"ifGnwPMt3SkJV7/3Mn/o/mAWCwIeqTAurMpf2WqoIoka+c6QXjkh9dlsf8Yeqk5Zw7i0GWD3uvEzT5IUDf7oBg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"fb16cd5924717fe7255a1dd40552be73f4e04b56839670fb76cc29dcc3d3698a","last_reissued_at":"2026-05-18T02:31:03.609721Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:31:03.609721Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1411.6267","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T02:31:03Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"n51+rbhmjVxU+MG5nbmLHJ/iRWhsxayzYuVJX1op0XOJVdu2mq4qKshX45baDTZ4qGRv8TzwemCCrn/Om+keCQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-21T13:17:51.829454Z"},"content_sha256":"0347faaa33cb7de237475bec444e065c1001d0a6567b138b45c62f457604a8c1","schema_version":"1.0","event_id":"sha256:0347faaa33cb7de237475bec444e065c1001d0a6567b138b45c62f457604a8c1"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2014:7MLM2WJEOF76OJK2DXKAKUV6OP","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"FellWalker - a Clump Identification Algorithm","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.IM","authors_text":"David Berry","submitted_at":"2014-11-23T16:57:12Z","abstract_excerpt":"This paper describes the FellWalker algorithm, a watershed algorithm that segments a 1-, 2- or 3-dimensional array of data values into a set of disjoint clumps of emission, each containing a single significant peak. Pixels below a nominated constant data level are assumed to be background pixels and are not assigned to any clump. FellWalker is thus equivalent in purpose to the CLUMPFIND algorithm. However, unlike CLUMPFIND, which segments the array on the basis of a set of evenly-spaced contours and thus uses only a small fraction of the available data values, the FellWalker algorithm is based"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1411.6267","kind":"arxiv","version":1},"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":"2026-05-18T02:31:03Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"wp3bw7ULR/00fxTopjRw5iLdUtpGTqZN+rmawe1HzXV6aAbJ7c/ak/N0bSq8NeJJNFPJaUGvp7GTOpvFwXrmAA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-21T13:17:51.829801Z"},"content_sha256":"28e9377a52e812e6872aef9e02281817e5c5d69f011b45cd6c64eb399cc16b62","schema_version":"1.0","event_id":"sha256:28e9377a52e812e6872aef9e02281817e5c5d69f011b45cd6c64eb399cc16b62"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/7MLM2WJEOF76OJK2DXKAKUV6OP/bundle.json","state_url":"https://pith.science/pith/7MLM2WJEOF76OJK2DXKAKUV6OP/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/7MLM2WJEOF76OJK2DXKAKUV6OP/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":"2026-05-21T13:17:51Z","links":{"resolver":"https://pith.science/pith/7MLM2WJEOF76OJK2DXKAKUV6OP","bundle":"https://pith.science/pith/7MLM2WJEOF76OJK2DXKAKUV6OP/bundle.json","state":"https://pith.science/pith/7MLM2WJEOF76OJK2DXKAKUV6OP/state.json","well_known_bundle":"https://pith.science/.well-known/pith/7MLM2WJEOF76OJK2DXKAKUV6OP/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2014:7MLM2WJEOF76OJK2DXKAKUV6OP","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":"4faec8118df3db2c22b6d6be8743474c5970f00c55f4763a563e5e4344523a6e","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2014-11-23T16:57:12Z","title_canon_sha256":"c160762668c09906d2e18216a3f0c6d17220064038ad36d6c3e379733466eed1"},"schema_version":"1.0","source":{"id":"1411.6267","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1411.6267","created_at":"2026-05-18T02:31:03Z"},{"alias_kind":"arxiv_version","alias_value":"1411.6267v1","created_at":"2026-05-18T02:31:03Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1411.6267","created_at":"2026-05-18T02:31:03Z"},{"alias_kind":"pith_short_12","alias_value":"7MLM2WJEOF76","created_at":"2026-05-18T12:28:19Z"},{"alias_kind":"pith_short_16","alias_value":"7MLM2WJEOF76OJK2","created_at":"2026-05-18T12:28:19Z"},{"alias_kind":"pith_short_8","alias_value":"7MLM2WJE","created_at":"2026-05-18T12:28:19Z"}],"graph_snapshots":[{"event_id":"sha256:28e9377a52e812e6872aef9e02281817e5c5d69f011b45cd6c64eb399cc16b62","target":"graph","created_at":"2026-05-18T02:31:03Z","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":"This paper describes the FellWalker algorithm, a watershed algorithm that segments a 1-, 2- or 3-dimensional array of data values into a set of disjoint clumps of emission, each containing a single significant peak. Pixels below a nominated constant data level are assumed to be background pixels and are not assigned to any clump. FellWalker is thus equivalent in purpose to the CLUMPFIND algorithm. However, unlike CLUMPFIND, which segments the array on the basis of a set of evenly-spaced contours and thus uses only a small fraction of the available data values, the FellWalker algorithm is based","authors_text":"David Berry","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2014-11-23T16:57:12Z","title":"FellWalker - a Clump Identification Algorithm"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1411.6267","kind":"arxiv","version":1},"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":"sha256:0347faaa33cb7de237475bec444e065c1001d0a6567b138b45c62f457604a8c1","target":"record","created_at":"2026-05-18T02:31:03Z","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":"4faec8118df3db2c22b6d6be8743474c5970f00c55f4763a563e5e4344523a6e","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2014-11-23T16:57:12Z","title_canon_sha256":"c160762668c09906d2e18216a3f0c6d17220064038ad36d6c3e379733466eed1"},"schema_version":"1.0","source":{"id":"1411.6267","kind":"arxiv","version":1}},"canonical_sha256":"fb16cd5924717fe7255a1dd40552be73f4e04b56839670fb76cc29dcc3d3698a","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"fb16cd5924717fe7255a1dd40552be73f4e04b56839670fb76cc29dcc3d3698a","first_computed_at":"2026-05-18T02:31:03.609721Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:31:03.609721Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"ifGnwPMt3SkJV7/3Mn/o/mAWCwIeqTAurMpf2WqoIoka+c6QXjkh9dlsf8Yeqk5Zw7i0GWD3uvEzT5IUDf7oBg==","signature_status":"signed_v1","signed_at":"2026-05-18T02:31:03.610161Z","signed_message":"canonical_sha256_bytes"},"source_id":"1411.6267","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:0347faaa33cb7de237475bec444e065c1001d0a6567b138b45c62f457604a8c1","sha256:28e9377a52e812e6872aef9e02281817e5c5d69f011b45cd6c64eb399cc16b62"],"state_sha256":"d2d5115fded6b932b0b1255a551d26051db228e8ff19377e098c48dc90a7bbf6"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ecSZ22dJBSHMFJY+UH5DIS0NvrTJEYa4KvRZE/tHT0IpUWkHILglPKc47ENn5MN5Lf8/EC7avz1Cmeijx/yZBw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-21T13:17:51.831861Z","bundle_sha256":"aee5e001fb576c1a69bfd4df9dbdab9d5f373377e850108e3ff3579a67c37f61"}}