ANSI and ISO Density

Density may be calculated from LabColor instances.

colormath.density.auto_density(color)[source]

Given a SpectralColor, automatically choose the correct ANSI T filter. Returns a tuple with a string representation of the filter the calculated density.

Parameters:color (SpectralColor) – The SpectralColor object to calculate density for.
Return type:float
Returns:The density value, with the filter selected automatically.
colormath.density.ansi_density(color, density_standard)[source]

Calculates density for the given SpectralColor using the spectral weighting function provided. For example, ANSI_STATUS_T_RED. These may be found in colormath.density_standards.

Parameters:
  • color (SpectralColor) – The SpectralColor object to calculate density for.
  • std_array (numpy.ndarray) – NumPy array of filter of choice from colormath.density_standards.
Return type:

float
Returns:

The density value for the given color and density standard.

Example

from colormath.color_objects import SpectralColor
from colormath.density import auto_density, ansi_density
from colormath.density_standards import ANSI_STATUS_T_RED

# Omitted the full spectral kwargs for brevity.
color = SpectralColor(spec_340nm=0.08, ...)
# ANSI T Density for the spectral color.
density = auto_density(color)

# Or maybe we want to specify which filter to use.
red_density = ansi_density(color, ANSI_STATUS_T_RED)

Valid Density Constants

The following density constants within colormath.density_standards can be passed to colormath.density.ansi_density():

  • ANSI_STATUS_A_RED
  • ANSI_STATUS_A_GREEN
  • ANSI_STATUS_A_BLUE
  • ANSI_STATUS_E_RED
  • ANSI_STATUS_E_GREEN
  • ANSI_STATUS_E_BLUE
  • ANSI_STATUS_M_RED
  • ANSI_STATUS_M_GREEN
  • ANSI_STATUS_M_BLUE
  • ANSI_STATUS_T_RED
  • ANSI_STATUS_T_GREEN
  • ANSI_STATUS_T_BLUE
  • TYPE1
  • TYPE2
  • ISO_VISUAL