{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2021:3POX4UYOQLKMDAR77BW3MLU6GE","short_pith_number":"pith:3POX4UYO","canonical_record":{"source":{"id":"2109.03144","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2021-09-07T15:24:40Z","cross_cats_sorted":[],"title_canon_sha256":"e55e915eb9bb43a33c6198b542b4876763d6d89a237c2fb489bc8a574435d3a3","abstract_canon_sha256":"f42e613e254f0ade830018d2188842656a9fe0ab1e6a7ee64f515525b2422900"},"schema_version":"1.0"},"canonical_sha256":"dbdd7e530e82d4c1823ff86db62e9e3102df481dc6d815a59a226ffcb06b2313","source":{"kind":"arxiv","id":"2109.03144","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2109.03144","created_at":"2026-07-05T03:21:59Z"},{"alias_kind":"arxiv_version","alias_value":"2109.03144v2","created_at":"2026-07-05T03:21:59Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2109.03144","created_at":"2026-07-05T03:21:59Z"},{"alias_kind":"pith_short_12","alias_value":"3POX4UYOQLKM","created_at":"2026-07-05T03:21:59Z"},{"alias_kind":"pith_short_16","alias_value":"3POX4UYOQLKMDAR7","created_at":"2026-07-05T03:21:59Z"},{"alias_kind":"pith_short_8","alias_value":"3POX4UYO","created_at":"2026-07-05T03:21:59Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2021:3POX4UYOQLKMDAR77BW3MLU6GE","target":"record","payload":{"canonical_record":{"source":{"id":"2109.03144","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2021-09-07T15:24:40Z","cross_cats_sorted":[],"title_canon_sha256":"e55e915eb9bb43a33c6198b542b4876763d6d89a237c2fb489bc8a574435d3a3","abstract_canon_sha256":"f42e613e254f0ade830018d2188842656a9fe0ab1e6a7ee64f515525b2422900"},"schema_version":"1.0"},"canonical_sha256":"dbdd7e530e82d4c1823ff86db62e9e3102df481dc6d815a59a226ffcb06b2313","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T03:21:59.623279Z","signature_b64":"42T3k/18estTz9yAEnP/47LwWn6NCqYaG7GotBtYUD1TB/uPqDOIwppMQTHpgZn4rx+YKBykfTdRnaPnHb4uBw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"dbdd7e530e82d4c1823ff86db62e9e3102df481dc6d815a59a226ffcb06b2313","last_reissued_at":"2026-07-05T03:21:59.622778Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T03:21:59.622778Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2109.03144","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":"2026-07-05T03:21:59Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"YTYi28JXrAwTCn+RQ8AU0X7hcUMf+w00RvINkZBHrPz35QT0ea60qJpte3OJqkmkD0avKQhkM0VikjPZyo83CA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-05T14:13:08.596718Z"},"content_sha256":"5e99f9b0969a29e3f94ba3ca09946eef06e8d1bbd372d3ddfe1fc2250952b0fe","schema_version":"1.0","event_id":"sha256:5e99f9b0969a29e3f94ba3ca09946eef06e8d1bbd372d3ddfe1fc2250952b0fe"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2021:3POX4UYOQLKMDAR77BW3MLU6GE","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"PP-OCRv2: Bag of Tricks for Ultra Lightweight OCR System","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cs.CV","authors_text":"Bin Lu, Cheng Cui, Chenxia Li, Dianhai Yu, Jun Zhou, Qiwen Liu, Ruoyu Guo, Weiwei Liu, Xiaoguang Hu, Yanjun Ma, Yehua Yang, Yuning Du","submitted_at":"2021-09-07T15:24:40Z","abstract_excerpt":"Optical Character Recognition (OCR) systems have been widely used in various of application scenarios. Designing an OCR system is still a challenging task. In previous work, we proposed a practical ultra lightweight OCR system (PP-OCR) to balance the accuracy against the efficiency. In order to improve the accuracy of PP-OCR and keep high efficiency, in this paper, we propose a more robust OCR system, i.e. PP-OCRv2. We introduce bag of tricks to train a better text detector and a better text recognizer, which include Collaborative Mutual Learning (CML), CopyPaste, Lightweight CPUNetwork (LCNet"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2109.03144","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/2109.03144/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":"2026-07-05T03:21:59Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"D3rfBK/+CZOtiJ6O4+kwkZRPY9fnoSqCibwu2dWcLfT2uVjI4ZaosFErqmQW9PawAfgekAUU13tFx0FiI6m+BQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-05T14:13:08.597334Z"},"content_sha256":"3ae0fa0c52c8722c9ae97df98d79360ca6ee886f13d6f0828481f4c8b94ba406","schema_version":"1.0","event_id":"sha256:3ae0fa0c52c8722c9ae97df98d79360ca6ee886f13d6f0828481f4c8b94ba406"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/3POX4UYOQLKMDAR77BW3MLU6GE/bundle.json","state_url":"https://pith.science/pith/3POX4UYOQLKMDAR77BW3MLU6GE/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/3POX4UYOQLKMDAR77BW3MLU6GE/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":"2026-07-05T14:13:08Z","links":{"resolver":"https://pith.science/pith/3POX4UYOQLKMDAR77BW3MLU6GE","bundle":"https://pith.science/pith/3POX4UYOQLKMDAR77BW3MLU6GE/bundle.json","state":"https://pith.science/pith/3POX4UYOQLKMDAR77BW3MLU6GE/state.json","well_known_bundle":"https://pith.science/.well-known/pith/3POX4UYOQLKMDAR77BW3MLU6GE/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2021:3POX4UYOQLKMDAR77BW3MLU6GE","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":"f42e613e254f0ade830018d2188842656a9fe0ab1e6a7ee64f515525b2422900","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2021-09-07T15:24:40Z","title_canon_sha256":"e55e915eb9bb43a33c6198b542b4876763d6d89a237c2fb489bc8a574435d3a3"},"schema_version":"1.0","source":{"id":"2109.03144","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2109.03144","created_at":"2026-07-05T03:21:59Z"},{"alias_kind":"arxiv_version","alias_value":"2109.03144v2","created_at":"2026-07-05T03:21:59Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2109.03144","created_at":"2026-07-05T03:21:59Z"},{"alias_kind":"pith_short_12","alias_value":"3POX4UYOQLKM","created_at":"2026-07-05T03:21:59Z"},{"alias_kind":"pith_short_16","alias_value":"3POX4UYOQLKMDAR7","created_at":"2026-07-05T03:21:59Z"},{"alias_kind":"pith_short_8","alias_value":"3POX4UYO","created_at":"2026-07-05T03:21:59Z"}],"graph_snapshots":[{"event_id":"sha256:3ae0fa0c52c8722c9ae97df98d79360ca6ee886f13d6f0828481f4c8b94ba406","target":"graph","created_at":"2026-07-05T03:21:59Z","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/2109.03144/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Optical Character Recognition (OCR) systems have been widely used in various of application scenarios. Designing an OCR system is still a challenging task. In previous work, we proposed a practical ultra lightweight OCR system (PP-OCR) to balance the accuracy against the efficiency. In order to improve the accuracy of PP-OCR and keep high efficiency, in this paper, we propose a more robust OCR system, i.e. PP-OCRv2. We introduce bag of tricks to train a better text detector and a better text recognizer, which include Collaborative Mutual Learning (CML), CopyPaste, Lightweight CPUNetwork (LCNet","authors_text":"Bin Lu, Cheng Cui, Chenxia Li, Dianhai Yu, Jun Zhou, Qiwen Liu, Ruoyu Guo, Weiwei Liu, Xiaoguang Hu, Yanjun Ma, Yehua Yang, Yuning Du","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2021-09-07T15:24:40Z","title":"PP-OCRv2: Bag of Tricks for Ultra Lightweight OCR System"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2109.03144","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":"sha256:5e99f9b0969a29e3f94ba3ca09946eef06e8d1bbd372d3ddfe1fc2250952b0fe","target":"record","created_at":"2026-07-05T03:21:59Z","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":"f42e613e254f0ade830018d2188842656a9fe0ab1e6a7ee64f515525b2422900","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CV","submitted_at":"2021-09-07T15:24:40Z","title_canon_sha256":"e55e915eb9bb43a33c6198b542b4876763d6d89a237c2fb489bc8a574435d3a3"},"schema_version":"1.0","source":{"id":"2109.03144","kind":"arxiv","version":2}},"canonical_sha256":"dbdd7e530e82d4c1823ff86db62e9e3102df481dc6d815a59a226ffcb06b2313","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"dbdd7e530e82d4c1823ff86db62e9e3102df481dc6d815a59a226ffcb06b2313","first_computed_at":"2026-07-05T03:21:59.622778Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T03:21:59.622778Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"42T3k/18estTz9yAEnP/47LwWn6NCqYaG7GotBtYUD1TB/uPqDOIwppMQTHpgZn4rx+YKBykfTdRnaPnHb4uBw==","signature_status":"signed_v1","signed_at":"2026-07-05T03:21:59.623279Z","signed_message":"canonical_sha256_bytes"},"source_id":"2109.03144","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:5e99f9b0969a29e3f94ba3ca09946eef06e8d1bbd372d3ddfe1fc2250952b0fe","sha256:3ae0fa0c52c8722c9ae97df98d79360ca6ee886f13d6f0828481f4c8b94ba406"],"state_sha256":"beee575c99e20d99206b77b0f9884cc40e531bee4b891f7532cef0b20931e03c"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"I5EPOzUPQtHdsVY/B3eO9MyfZPs95a1ow0t97NV6PhngwPHMh2/P7GMsr8ROthHfQKQXeX6pjdgW8KWmvepvBw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-07-05T14:13:08.600553Z","bundle_sha256":"e4bf173166ea2707026e40655e6f5f93b04e9d19063438e0429c59f9340f9893"}}