color_tools.constants

Immutable color science constants from international standards.

These values are defined by CIE (International Commission on Illumination), sRGB specification, and various color difference formulas. They should never be modified as they represent fundamental color science.

class color_tools.constants.ColorConstants[source]

Bases: object

Immutable color science constants from international standards.

These values are defined by CIE (International Commission on Illumination), sRGB specification, and various color difference formulas. They should never be modified as they represent fundamental color science.

D65_WHITE_X = 95.047

D65_WHITE_Y = 100.0

D65_WHITE_Z = 108.883

SRGB_TO_XYZ_R = (0.4124564, 0.3575761, 0.1804375)

SRGB_TO_XYZ_G = (0.2126729, 0.7151522, 0.072175)

SRGB_TO_XYZ_B = (0.0193339, 0.119192, 0.9503041)

XYZ_TO_SRGB_X = (3.2404542, -1.5371385, -0.4985314)

XYZ_TO_SRGB_Y = (-0.969266, 1.8760108, 0.041556)

XYZ_TO_SRGB_Z = (0.0556434, -0.2040259, 1.0572252)

SRGB_GAMMA_THRESHOLD = 0.04045

SRGB_GAMMA_LINEAR_SCALE = 12.92

SRGB_GAMMA_OFFSET = 0.055

SRGB_GAMMA_DIVISOR = 1.055

SRGB_GAMMA_POWER = 2.4

SRGB_INV_GAMMA_THRESHOLD = 0.0031308

LAB_DELTA = 0.20689655172413793

LAB_KAPPA = 116.0

LAB_OFFSET = 16.0

LAB_A_SCALE = 500.0

LAB_B_SCALE = 200.0

DE94_K1 = 0.045

DE94_K2 = 0.015

DE2000_POW7_BASE = 25.0

DE2000_HUE_OFFSET_1 = 30.0

DE2000_HUE_WEIGHT_1 = 0.17

DE2000_HUE_MULT_2 = 2.0

DE2000_HUE_WEIGHT_2 = 0.24

DE2000_HUE_MULT_3 = 3.0

DE2000_HUE_OFFSET_3 = 6.0

DE2000_HUE_WEIGHT_3 = 0.32

DE2000_HUE_MULT_4 = 4.0

DE2000_HUE_OFFSET_4 = 63.0

DE2000_HUE_WEIGHT_4 = 0.2

DE2000_DRO_MULT = 30.0

DE2000_DRO_CENTER = 275.0

DE2000_DRO_DIVISOR = 25.0

DE2000_L_WEIGHT = 0.015

DE2000_L_OFFSET = 50.0

DE2000_L_DIVISOR = 20.0

DE2000_C_WEIGHT = 0.045

DE2000_H_WEIGHT = 0.015

CMC_L_THRESHOLD = 16.0

CMC_L_LOW = 0.511

CMC_L_SCALE = 0.040975

CMC_L_DIVISOR = 0.01765

CMC_C_SCALE = 0.0638

CMC_C_DIVISOR = 0.0131

CMC_C_OFFSET = 0.638

CMC_HUE_MIN = 164.0

CMC_HUE_MAX = 345.0

CMC_T_IN_RANGE = 0.56

CMC_T_COS_MULT_IN = 0.2

CMC_T_HUE_OFFSET_IN = 168.0

CMC_T_OUT_RANGE = 0.36

CMC_T_COS_MULT_OUT = 0.4

CMC_T_HUE_OFFSET_OUT = 35.0

CMC_F_POWER = 4.0

CMC_F_DIVISOR = 1900.0

CMC_L_DEFAULT = 2.0

CMC_C_DEFAULT = 1.0

HUE_CIRCLE_DEGREES = 360.0

HUE_HALF_CIRCLE_DEGREES = 180.0

RGB_MIN = 0

RGB_MAX = 255

NORMALIZED_MIN = 0.0

NORMALIZED_MAX = 1.0

XYZ_SCALE_FACTOR = 100.0

WIN_HSL_MAX = 240.0

AB_MIN = -128.0

AB_MAX = 127.0

CHROMA_MIN = 0.0

CHROMA_MAX = 181.0

COLORS_JSON_FILENAME = 'colors.json'

FILAMENTS_JSON_FILENAME = 'filaments.json'

MAKER_SYNONYMS_JSON_FILENAME = 'maker_synonyms.json'

LAB_DELTA_CUBED = 0.008856451679035631

LAB_F_SCALE = 0.12841854934601665

LAB_F_OFFSET = 0.13793103448275862

classmethod verify_integrity()[source]

Verify that constants haven’t been modified.

Return type:: bool
Returns:: True if all constants match expected values, False if tampered with.

COLORS_JSON_HASH = 'dc8ce5769a2186008af540c03159d3f24a72e5effc9ce5b611c8b4374da19ffd'

FILAMENTS_JSON_HASH = '8e3e178cf824b7e1bcf34b67bfa929e462964334c79069073806a9a959f3536e'

MAKER_SYNONYMS_JSON_HASH = '27488f9dfa37d661a0d5c0f73d1680aea22ab909f1c94fe1dd576b7902245c81'

APPLE2_PALETTE_HASH = 'd5374e50f76312799c031a8f64fe9537cac2d903c59dbc09f0760e8f5bb581fe'

CGA4_PALETTE_HASH = '62624dbeef28b664feca10afe3901b52b2335395134aba88ea21f955f0d17b7d'

CGA16_PALETTE_HASH = 'd189b3004d20a343105d01b03c71d437077e34bb8d25fc074487c35c8490a329'

COMMODORE64_PALETTE_HASH = 'c4502abaed781535de55f3042cca4d7b3653c5eeb4cec3ecb30f591bfbfdfcca'

CRAYOLA_PALETTE_HASH = '65bf4add677a7a8667114b8f813b8afdd6b8e92e8cef1458e53b4a8cd716a4a3'

EGA16_PALETTE_HASH = 'd189b3004d20a343105d01b03c71d437077e34bb8d25fc074487c35c8490a329'

EGA64_PALETTE_HASH = '2159e51f89cca4a4fb43a2d80bea030f3d7cd0cc5e1eacd25eb95f0ce2027e7f'

GAMEBOY_PALETTE_HASH = 'e2911baed15b4d56a27313b6be506c3a1f57bee3b01ecd2ca5995b512822da9b'

GAMEBOY_COLOR_PALETTE_HASH = '5c98dd69be991f445aabafe21a0bdddabc8f6e98aa728724e3d0e72a445aadde'

GAMEBOY_DMG_PALETTE_HASH = '042d7cfd7b94f8719aa01603ddf5b0d9c73ae59b04e27295132ddac13142e968'

GAMEBOY_GBL_PALETTE_HASH = 'f2b6a573b09c1efa3529e79f281dcb0ed4e5c788cb10e51526c60e6e5d928231'

GAMEBOY_MGB_PALETTE_HASH = '7c556e05e13adcfce0e7aec06ded6c7871acee63771e520319afa67e07080027'

MACINTOSH_PALETTE_HASH = 'e9b5bce3ce2eda12dec5793b4eb3c588a92d53e8d6ecaf4fa310998fe2dd1ddd'

NES_PALETTE_HASH = '3021573a00b158fb6cf694e6546b236c2ec6862d52e08cc860f32d983e1f0a59'

SMS_PALETTE_HASH = '95010c348c2f77a209544170da29ee7f5bfccacbcd32ed33c36cb7ef269f72e8'

TANDY16_PALETTE_HASH = '820f2f1dcdd3acd7130a88247b09e6bf969779a08c97091800db19c1748f1a03'

VGA_PALETTE_HASH = '9eb6055508d5523ceafbb4abe3d2921f09bc61b20485da1052e4d4fd653a5d00'

VIRTUALBOY_PALETTE_HASH = '218854f6dc6506649e6ff14f92f56ff996b7c01a36c916b0374880c8524c40a9'

WEB_PALETTE_HASH = 'ba4ad53ece01d2f1338ae13221aa04e5c342519d7750d948458074001a465e7d'

USER_COLORS_JSON_FILENAME = 'user/user-colors.json'

USER_FILAMENTS_JSON_FILENAME = 'user/user-filaments.json'

USER_SYNONYMS_JSON_FILENAME = 'user/user-synonyms.json'

MATRICES_EXPECTED_HASH = 'd177316ade5146a084bb5b92d693c3f9c62ec593fde9b6face567dbd8a633df5'

static verify_data_file(filepath, expected_hash)[source]

Verify integrity of a data file using SHA-256 hash.

Parameters:

filepath (Path) – Path to the data file to verify
expected_hash (str) – Expected SHA-256 hash of the file contents

Return type:

bool

Returns:

True if file hash matches expected hash, False otherwise

classmethod verify_all_data_files(data_dir=None)[source]

Verify integrity of all core data files.

Parameters:: data_dir (Path | None) – Directory containing data files. If None, uses package data directory.
Return type:: tuple[bool, list[str]]
Returns:: Tuple of (all_valid, list_of_errors) - all_valid: True if all files pass verification - list_of_errors: List of error messages for any failed verifications

classmethod verify_matrices_integrity()[source]

Verify that transformation matrices haven’t been modified.

Return type:: bool
Returns:: True if all matrices match expected values, False if tampered with.

classmethod generate_user_data_hash(file_path)[source]

Generate SHA-256 hash for a user data file.

Parameters:: file_path (Path | str) – Path to user data file
Return type:: str
Returns:: SHA-256 hash of the file contents
Raises:: FileNotFoundError – If file doesn’t exist

classmethod save_user_data_hash(file_path, hash_value=None)[source]

Save SHA-256 hash for a user data file to a .sha256 file.

Parameters:

file_path (Path | str) – Path to user data file
hash_value (str | None) – Optional pre-computed hash. If None, will compute from file.

Return type:

Path

Returns:

Path to the created .sha256 file

Raises:

FileNotFoundError – If file doesn’t exist

classmethod verify_user_data_file(file_path)[source]

Verify user data file against its .sha256 file if it exists.

Parameters:: file_path (Path | str) – Path to user data file
Return type:: tuple[bool, str | None]
Returns:: Tuple of (is_valid, error_message) - is_valid: True if file is valid or no hash file exists - error_message: None if valid, error description if invalid

classmethod verify_all_user_data(data_dir=None)[source]

Verify integrity of all user data files in the user/ subdirectory.

Only files with corresponding .sha256 files are verified.

Parameters:: data_dir (Path | str | None) – Optional custom data directory. If None, uses package data directory.
Return type:: tuple[bool, list[str]]
Returns:: Tuple of (all_valid, list_of_errors) - all_valid: True if all files with hash files pass verification - list_of_errors: List of error messages for any failed verifications