Data repository for the RAW to ACES Utility

Table of Contents

1. Introduction
2. Package Contents
3. JSON Schema for Spectral Datasets
4. License

Introduction

This is the data repository for the RAW to ACES Utility or rawtoaces (https://github.com/AcademySoftwareFoundation/rawtoaces), a software package that converts digital camera RAW files to ACES container files containing image data encoded according to the Academy Color Encoding Specification (ACES) as specified in SMPTE 2065-1. The output image complies with the ACES Container specification (SMPTE S2065-4).

Package Contents

The repository contains the following:

• data/camera/ - camera spectral sensitivities
• data/illuminant/ - light source spectral power distribution
• data/cmf/ - color matching functions (CIE-1931)
• data/training/ - 190 training patch dataset

JSON Schema for Spectral Datasets

The schema takes its roots in IES TM-27-14 but implements support for multiple spectral datasets while adopting JSON over XML for the simplicity of its grammar.

rawtoaces expects the spectral dataset to have the following shape: (380, 780, 5), i.e. starting from 380nm and ending at 780nm with a 5nm interval/bin size.

The attributes are defined as follows:

• header
  • schema_version
    • description: Required, schema version of the current document.
    • type: "string"
  • comments
    • description: Optional, additional information for the spectral dataset.
    • type: ["string", "null"]
  • description
    • description: Required, description of the spectral dataset.
    • type: "string"
  • document_creation_date
    • description: Required, document creation date expressed as per RFC 3339 - Date and Time on the Internet: Timestamps, e.g. 2017-01-01T12:00:00Z.
    • type: "string"
    • format: "date-time"
  • document_creator
    • description: Required, creator of the document, e.g. company, individual, laboratory, etc.
    • type: "string"
  • laboratory
    • description: Optional, laboratory or company that performed the measurements.
    • type: ["string", "null"]
  • license
    • description: Required, usage license of the document, e.g. "CC-BY-NC-ND".
    • type: ["string", "null"]
  • manufacturer
    • description: Optional, manufacturer of the device being tested.
    • type: ["string", "null"]
  • measurement_equipment
    • description: Optional, measurement equipment used to test the device.
    • type: ["string", "null"]
  • model
    • description: Optional, model of the device being tested.
    • type: ["string", "null"]
  • type
    • description: Optional, type of the spectral dataset.
    • type: ["string", "null"]
  • unique_identifier
    • description: Optional, generated unique identifier for the document, e.g. SHA256.
    • type: ["string", "null"]
• spectral_data
  • bandwidth_FWHM
    • description: Optional, spectro-radiometer full-width at half-maximum bandwidth in nm.
    • type: ["number", "null"]
  • bandwidth_corrected
    • description: Optional, whether bandwidth correction has been applied to the spectral data.
    • type: ["boolean", "null"]
  • data
    • description: Required, defines the spectral dataset, requiring at least one key from index whose value is an object containing wavelength/value pairs.
    • type: "object"
  • index
    • description: Required, indexes the spectral dataset.
    • type: "object"
  • reflection_geometry
    • description: Required if units is reflectance, reflection geometry attributes as per CIE 15:2004.
    • type: ["string", "null"]
    • enum: ["di:8", "de:8", "8:di", "8:de", "d:d", "d:0", "45a:0", "45c:0", "0:45a", "45x:0", "0:45x", "other", null]
  • transmission_geometry
    • description: Required if units is transmittance, transmission geometry attributes as per CIE 15:2004.
    • type: ["string", "null"]
    • enum: ["0:0", "di:0", "de:0", "0:di", "0:de", "d:d", "other", null]
  • units
    • description: Required, unit or quantity of measurement for the spectral dataset.
    • type: "string"
    • enum: ["flux", "absorptance", "transmittance", "reflectance", "intensity", "irradiance", "radiance", "exitance", "R-Factor", "T-Factor", "relative", "other"]

The full JSON schema for spectral datasets can be used to validate a new user file using a validator and is defined in schema_1.0.0.json

Licence

rawtoaces-data is licensed under the Apache-2.0 license.