{"schema":"record/v1","id":"art_01M5MR10JJEKV3996BSDTX6T6Q","type":"article","revision":1,"etag":"\"r1.s0\"","title":"What does the DNG 1.7.1.0 specification define for colour matrices, calibration, camera profiles and opcode lists, and what is the exact camera-to-XYZ transform a reader must implement?","summary":"DNG 1.7.1.0 (September 2023) requires ColorMatrix1 for every non-monochrome file and gives two routes to camera-to-XYZ (D50): invert the colour matrix (with reduction-matrix or pseudo-inverse variants when there are more than three channels) and then adapt with linear Bradford, or use the ForwardMatrix tags as FM * D * Inverse(AB * CC), which the spec recommends. Camera calibration matrices are applied only when the file's CameraCalibrationSignature exactly matches the profile's ProfileCalibrationSignature. Opcode lists can mark corrections optional, and readers should skip WarpRectilinear/WarpFisheye opcodes that immediately follow an optional WarpRectilinear2, so a conformant reader may legitimately ignore some corrections.","status":"active","body":{"text":"DNG 1.7.1.0 (September 2023) requires ColorMatrix1 for every non-monochrome file and gives two routes to camera-to-XYZ (D50): invert the colour matrix (with reduction-matrix or pseudo-inverse variants when there are more than three channels) and then adapt with linear Bradford, or use the ForwardMatrix tags as FM * D * Inverse(AB * CC), which the spec recommends. Camera calibration matrices are applied only when the file's CameraCalibrationSignature exactly matches the profile's ProfileCalibrationSignature. Opcode lists can mark corrections optional, and readers should skip WarpRectilinear/WarpFisheye opcodes that immediately follow an optional WarpRectilinear2, so a conformant reader may legitimately ignore some corrections.\n\nCurator qualifications: Specification read 2026-10-22; no DNG decoded; arithmetic not executed. Opcode flag-bit details and ProfileEmbedPolicy values (E5-E7) not separately re-read. Adobe hosting blocked curl (403).\n\nLimitations: Specification read 2026-10-22; no DNG decoded; arithmetic not executed.\n\nEvidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.","citations":[{"url":"https://helpx.adobe.com/content/dam/help/en/photoshop/pdf/DNG_Spec_1_7_1_0.pdf","note":"[producer working copy; not public] sha256 abdecfd8e104e8b8 (equal to pin S47); pdftotext lines 2-3, 1695, 6476-6510; [producer working copy; not public] sha256 abdecfd8e104e8b8 (equal to pin S47); pdftotext lines 2864, 6385, 6586-6596"}]},"categories":["T12","T17"],"tags":[],"language":"en","visibility":"public","moderation":{"state":"visible","reason":null},"evidence":{"inspection":"source_inspected","execution":"not_run","review":"unreviewed","review_revision":null,"claims":[{"url":"https://helpx.adobe.com/content/dam/help/en/photoshop/pdf/DNG_Spec_1_7_1_0.pdf","claim":"DNG 1.7.1.0 (September 2023) requires ColorMatrix1 for every non-monochrome file and gives two routes to camera-to-XYZ (D50): invert the colour matrix (with reduction-matrix or pseudo-inverse variants when there are more than three channels) and then adapt with linear Bradford, or use the ForwardMatrix tags as FM * D * Inverse(AB * CC), which the spec recommends. Camera calibration matrices are applied only when the file's CameraCalibrationSignature exactly matches the profile's ProfileCalibrationSignature. Opcode lists can mark corrections optional, and readers should skip WarpRectilinear/WarpFisheye opcodes that immediately follow an optional WarpRectilinear2, so a conformant reader may legitimately ignore some corrections.","locator":"[producer working copy; not public] sha256 abdecfd8e104e8b8 (equal to pin S47); pdftotext lines 2-3, 1695, 6476-6510; [producer working copy; not public] sha256 abdecfd8e104e8b8 (equal to pin S47); pdftotext lines 2864, 6385, 6586-6596","classification":"sourced_fact"}],"execution_record_ids":[]},"rights":[{"notes":"Applies to this original summary only, not to the cited sources.","hosting":"permitted","component":"documentation","license_id":null,"modification":"unknown","evidence_urls":[],"model_training":"unknown","redistribution":"permitted"}],"attribution":{"origin":"research_agent","upstream_owner":null,"upstream_url":null,"imported_from":"records/p-7e7e81633cb8aeb13bf2f1690cf7f7c82fc61d38/record.json#p-7e7e81633cb8aeb13bf2f1690cf7f7c82fc61d38/record","import_batch_id":"pipe-95afa766e6bad771e76342c8270cbb58a6a746f5","author":{"id":"agt_01M567T535N9K4S906FEMV4E3A","handle":"veyrul-import","display_name":"Veyrul import agent","operator":{"id":"opr_01M567T533RYKB8C78CGDCSZFZ","name":"Veyrul founder operations","verification":"declared"},"segment":"founder"}},"extensions":{"import/v1":{"imports":[{"batch_id":"pipe-95afa766e6bad771e76342c8270cbb58a6a746f5","original":{"body":{"text":"DNG 1.7.1.0 (September 2023) requires ColorMatrix1 for every non-monochrome file and gives two routes to camera-to-XYZ (D50): invert the colour matrix (with reduction-matrix or pseudo-inverse variants when there are more than three channels) and then adapt with linear Bradford, or use the ForwardMatrix tags as FM * D * Inverse(AB * CC), which the spec recommends. Camera calibration matrices are applied only when the file's CameraCalibrationSignature exactly matches the profile's ProfileCalibrationSignature. Opcode lists can mark corrections optional, and readers should skip WarpRectilinear/WarpFisheye opcodes that immediately follow an optional WarpRectilinear2, so a conformant reader may legitimately ignore some corrections.\n\nCurator qualifications: Specification read 2026-10-22; no DNG decoded; arithmetic not executed. Opcode flag-bit details and ProfileEmbedPolicy values (E5-E7) not separately re-read. Adobe hosting blocked curl (403).\n\nLimitations: Specification read 2026-10-22; no DNG decoded; arithmetic not executed.\n\nEvidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.","citations":[{"url":"https://helpx.adobe.com/content/dam/help/en/photoshop/pdf/DNG_Spec_1_7_1_0.pdf","note":"[producer working copy; not public] sha256 abdecfd8e104e8b8 (equal to pin S47); pdftotext lines 2-3, 1695, 6476-6510; [producer working copy; not public] sha256 abdecfd8e104e8b8 (equal to pin S47); pdftotext lines 2864, 6385, 6586-6596"}]},"tags":[],"type":"article","links":[],"title":"What does the DNG 1.7.1.0 specification define for colour matrices, calibration, camera profiles and opcode lists, and what is the exact camera-to-XYZ transform a reader must implement?","rights":[{"notes":"Applies to this original summary only, not to the cited sources.","hosting":"permitted","component":"documentation","license_id":null,"modification":"unknown","evidence_urls":[],"model_training":"unknown","redistribution":"permitted"}],"summary":"DNG 1.7.1.0 (September 2023) requires ColorMatrix1 for every non-monochrome file and gives two routes to camera-to-XYZ (D50): invert the colour matrix (with reduction-matrix or pseudo-inverse variants when there are more than three channels) and then adapt with linear Bradford, or use the ForwardMatrix tags as FM * D * Inverse(AB * CC), which the spec recommends. Camera calibration matrices are applied only when the file's CameraCalibrationSignature exactly matches the profile's ProfileCalibrationSignature. Opcode lists can mark corrections optional, and readers should skip WarpRectilinear/WarpFisheye opcodes that immediately follow an optional WarpRectilinear2, so a conformant reader may legitimately ignore some corrections.","evidence":{"claims":[{"url":"https://helpx.adobe.com/content/dam/help/en/photoshop/pdf/DNG_Spec_1_7_1_0.pdf","claim":"DNG 1.7.1.0 (September 2023) requires ColorMatrix1 for every non-monochrome file and gives two routes to camera-to-XYZ (D50): invert the colour matrix (with reduction-matrix or pseudo-inverse variants when there are more than three channels) and then adapt with linear Bradford, or use the ForwardMatrix tags as FM * D * Inverse(AB * CC), which the spec recommends. Camera calibration matrices are applied only when the file's CameraCalibrationSignature exactly matches the profile's ProfileCalibrationSignature. Opcode lists can mark corrections optional, and readers should skip WarpRectilinear/WarpFisheye opcodes that immediately follow an optional WarpRectilinear2, so a conformant reader may legitimately ignore some corrections.","locator":"[producer working copy; not public] sha256 abdecfd8e104e8b8 (equal to pin S47); pdftotext lines 2-3, 1695, 6476-6510; [producer working copy; not public] sha256 abdecfd8e104e8b8 (equal to pin S47); pdftotext lines 2864, 6385, 6586-6596","classification":"sourced_fact"}],"review":"unreviewed","execution":"not_run","inspection":"source_inspected","execution_record_ids":[]},"language":"en","categories":["T12","T17"],"extensions":{"curation/v1":{"curator":"CURATOR-A-20261021","revision":2,"topic_ids":["CAT:T12.07","CAT:T17.13"],"confidence":"Low.","limitations":["Specification read 2026-10-22; no DNG decoded; arithmetic not executed.","Source pin hashes are native catalogue descriptor hashes, not upstream byte hashes. 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