{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2018:OJ7SB6QBIZ3OGSV6M2VL2NCE7Y","short_pith_number":"pith:OJ7SB6QB","canonical_record":{"source":{"id":"1809.10801","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2018-09-27T23:59:24Z","cross_cats_sorted":[],"title_canon_sha256":"fede931f2eddb660a85d9f147b698b17bc021b41c4918e6bb0ffde24dda78111","abstract_canon_sha256":"88e73aa89dff3b426b22fbb5b63020c6a6c1016511c9caf106633c6e5a66e307"},"schema_version":"1.0"},"canonical_sha256":"727f20fa014676e34abe66aabd3444fe259cbce6da0808e5fc8f92bbfe2142b3","source":{"kind":"arxiv","id":"1809.10801","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1809.10801","created_at":"2026-05-18T00:04:35Z"},{"alias_kind":"arxiv_version","alias_value":"1809.10801v1","created_at":"2026-05-18T00:04:35Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1809.10801","created_at":"2026-05-18T00:04:35Z"},{"alias_kind":"pith_short_12","alias_value":"OJ7SB6QBIZ3O","created_at":"2026-05-18T12:32:43Z"},{"alias_kind":"pith_short_16","alias_value":"OJ7SB6QBIZ3OGSV6","created_at":"2026-05-18T12:32:43Z"},{"alias_kind":"pith_short_8","alias_value":"OJ7SB6QB","created_at":"2026-05-18T12:32:43Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2018:OJ7SB6QBIZ3OGSV6M2VL2NCE7Y","target":"record","payload":{"canonical_record":{"source":{"id":"1809.10801","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2018-09-27T23:59:24Z","cross_cats_sorted":[],"title_canon_sha256":"fede931f2eddb660a85d9f147b698b17bc021b41c4918e6bb0ffde24dda78111","abstract_canon_sha256":"88e73aa89dff3b426b22fbb5b63020c6a6c1016511c9caf106633c6e5a66e307"},"schema_version":"1.0"},"canonical_sha256":"727f20fa014676e34abe66aabd3444fe259cbce6da0808e5fc8f92bbfe2142b3","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:04:35.024856Z","signature_b64":"uhDIs868W3Ya3jkRffZgk4qs4N9EP48KTG1UaHfWgALVnj+pU79dHyxqcXUr82U/58k7suyRXAjMZWhbHmubAA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"727f20fa014676e34abe66aabd3444fe259cbce6da0808e5fc8f92bbfe2142b3","last_reissued_at":"2026-05-18T00:04:35.024398Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:04:35.024398Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1809.10801","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":"2026-05-18T00:04:35Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"HmRtJykLS2kRf9WU8DXWYaUnZGfpZCE2vl5FFAzrYly6Eocs25GQbxP90tGYtcw2zaoZ+k9mF9JKu1qmNMraBw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-21T01:40:22.016630Z"},"content_sha256":"4fd705417d5065ad397c8c73448829305b4b83999571372fa72abddebefebcb0","schema_version":"1.0","event_id":"sha256:4fd705417d5065ad397c8c73448829305b4b83999571372fa72abddebefebcb0"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2018:OJ7SB6QBIZ3OGSV6M2VL2NCE7Y","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Effective Cloud Detection and Segmentation using a Gradient-Based Algorithm for Satellite Imagery; Application to improve PERSIANN-CCS","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cs.CV","authors_text":"Fuqing Zhang, Kuo-lin Hsu, Negin Hayatbini, Soroosh Sorooshian, Yunji Zhang","submitted_at":"2018-09-27T23:59:24Z","abstract_excerpt":"Being able to effectively identify clouds and monitor their evolution is one important step toward more accurate quantitative precipitation estimation and forecast. In this study, a new gradient-based cloud-image segmentation technique is developed using tools from image processing techniques. This method integrates morphological image gradient magnitudes to separable cloud systems and patches boundaries. A varying scale-kernel is implemented to reduce the sensitivity of image segmentation to noise and capture objects with various finenesses of the edges in remote-sensing images. The proposed "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1809.10801","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":"2026-05-18T00:04:35Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"11EswzfR3h6v8HkVY1mGK5SlJK7o2HpBrJmmT+bQs4JrLtVWZ9Ol15GSTSsGMU6mDjmFhlf9z6Ko3npPM5nBBg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-21T01:40:22.017175Z"},"content_sha256":"b7d9a99a210d8362e27a2f7a9aff60c5e2c4ac541711090dee9644e2b9571de0","schema_version":"1.0","event_id":"sha256:b7d9a99a210d8362e27a2f7a9aff60c5e2c4ac541711090dee9644e2b9571de0"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/OJ7SB6QBIZ3OGSV6M2VL2NCE7Y/bundle.json","state_url":"https://pith.science/pith/OJ7SB6QBIZ3OGSV6M2VL2NCE7Y/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/OJ7SB6QBIZ3OGSV6M2VL2NCE7Y/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":"2026-08-21T01:40:22Z","links":{"resolver":"https://pith.science/pith/OJ7SB6QBIZ3OGSV6M2VL2NCE7Y","bundle":"https://pith.science/pith/OJ7SB6QBIZ3OGSV6M2VL2NCE7Y/bundle.json","state":"https://pith.science/pith/OJ7SB6QBIZ3OGSV6M2VL2NCE7Y/state.json","well_known_bundle":"https://pith.science/.well-known/pith/OJ7SB6QBIZ3OGSV6M2VL2NCE7Y/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:OJ7SB6QBIZ3OGSV6M2VL2NCE7Y","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":"88e73aa89dff3b426b22fbb5b63020c6a6c1016511c9caf106633c6e5a66e307","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2018-09-27T23:59:24Z","title_canon_sha256":"fede931f2eddb660a85d9f147b698b17bc021b41c4918e6bb0ffde24dda78111"},"schema_version":"1.0","source":{"id":"1809.10801","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1809.10801","created_at":"2026-05-18T00:04:35Z"},{"alias_kind":"arxiv_version","alias_value":"1809.10801v1","created_at":"2026-05-18T00:04:35Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1809.10801","created_at":"2026-05-18T00:04:35Z"},{"alias_kind":"pith_short_12","alias_value":"OJ7SB6QBIZ3O","created_at":"2026-05-18T12:32:43Z"},{"alias_kind":"pith_short_16","alias_value":"OJ7SB6QBIZ3OGSV6","created_at":"2026-05-18T12:32:43Z"},{"alias_kind":"pith_short_8","alias_value":"OJ7SB6QB","created_at":"2026-05-18T12:32:43Z"}],"graph_snapshots":[{"event_id":"sha256:b7d9a99a210d8362e27a2f7a9aff60c5e2c4ac541711090dee9644e2b9571de0","target":"graph","created_at":"2026-05-18T00:04:35Z","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":"Being able to effectively identify clouds and monitor their evolution is one important step toward more accurate quantitative precipitation estimation and forecast. In this study, a new gradient-based cloud-image segmentation technique is developed using tools from image processing techniques. This method integrates morphological image gradient magnitudes to separable cloud systems and patches boundaries. A varying scale-kernel is implemented to reduce the sensitivity of image segmentation to noise and capture objects with various finenesses of the edges in remote-sensing images. The proposed ","authors_text":"Fuqing Zhang, Kuo-lin Hsu, Negin Hayatbini, Soroosh Sorooshian, Yunji Zhang","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2018-09-27T23:59:24Z","title":"Effective Cloud Detection and Segmentation using a Gradient-Based Algorithm for Satellite Imagery; Application to improve PERSIANN-CCS"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1809.10801","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":"sha256:4fd705417d5065ad397c8c73448829305b4b83999571372fa72abddebefebcb0","target":"record","created_at":"2026-05-18T00:04:35Z","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":"88e73aa89dff3b426b22fbb5b63020c6a6c1016511c9caf106633c6e5a66e307","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2018-09-27T23:59:24Z","title_canon_sha256":"fede931f2eddb660a85d9f147b698b17bc021b41c4918e6bb0ffde24dda78111"},"schema_version":"1.0","source":{"id":"1809.10801","kind":"arxiv","version":1}},"canonical_sha256":"727f20fa014676e34abe66aabd3444fe259cbce6da0808e5fc8f92bbfe2142b3","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"727f20fa014676e34abe66aabd3444fe259cbce6da0808e5fc8f92bbfe2142b3","first_computed_at":"2026-05-18T00:04:35.024398Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:04:35.024398Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"uhDIs868W3Ya3jkRffZgk4qs4N9EP48KTG1UaHfWgALVnj+pU79dHyxqcXUr82U/58k7suyRXAjMZWhbHmubAA==","signature_status":"signed_v1","signed_at":"2026-05-18T00:04:35.024856Z","signed_message":"canonical_sha256_bytes"},"source_id":"1809.10801","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:4fd705417d5065ad397c8c73448829305b4b83999571372fa72abddebefebcb0","sha256:b7d9a99a210d8362e27a2f7a9aff60c5e2c4ac541711090dee9644e2b9571de0"],"state_sha256":"e7e7884435950bf383d42be3c164735fbdb673ccbff7148e445aa5cc2d97cf3b"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"QGfghTUnB5NjgMYib0vkIcsDSKC9uybxxkxYkThzS2sW2NezSDyP0ewTRvRsBmGHzsB6PhXRLATOgGBBxQFiAw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-21T01:40:22.021553Z","bundle_sha256":"418240470ba8f3c773c44c8265ea34623d68e7771ddb0e8766247d3a10ecd3ed"}}