colour_hdri.generation.weighting_functions Module

Weighting Functions

Defines weighting function objects used when generating radiance images:

colour_hdri.generation.weighting_functions.normal_distribution_function(a, mu=0.5, sigma=0.15)[source]

Returns given array weighted by a normal distribution function.

Parameters:
  • a (array_like) – Array to apply the weighting function onto.
  • mu (numeric, optional) – Mean or expectation.
  • sigma (numeric, optional) – Standard deviation.
Returns:

Weighted array.
Return type:

ndarray

Examples

>>> normal_distribution_function(np.linspace(0, 1, 10))
array([ 0.00386592,  0.03470859,  0.18002174,  0.53940751,  0.93371212,
        0.93371212,  0.53940751,  0.18002174,  0.03470859,  0.00386592])
colour_hdri.generation.weighting_functions.hat_function(a)[source]

Returns given array weighted by a hat function.

Parameters:a (array_like) – Array to apply the weighting function onto.
Returns:Weighted array.
Return type:ndarray

Examples

>>> hat_function(np.linspace(0, 1, 10))
array([ 0.        ,  0.95099207,  0.99913557,  0.99999812,  1.        ,
        1.        ,  0.99999812,  0.99913557,  0.95099207,  0.        ])
colour_hdri.generation.weighting_functions.weighting_function_Debevec1997(a, domain_l=0.01, domain_h=0.99)[source]

Returns given array weighted by Debevec (1997) function.

Parameters:
  • a (array_like) – Array to apply the weighting function onto.
  • domain_l (numeric, optional) – Domain lowest possible value, values less than domain_l will be set to zero.
  • domain_h (numeric, optional) – Domain highest possible value, values greater than domain_h will be set to zero.
Returns:

Weighted array.
Return type:

ndarray

References

[1]Debevec, P., & Malik, J. (1997). Recovering High Dynamic Range Radiance Maps from Photographs, (August), 1–10. doi:10.1145/258734.258884

Examples

>>> weighting_function_Debevec1997(np.linspace(0, 1, 10))
array([ 0.        ,  0.23273657,  0.48849105,  0.74424552,  1.        ,
        1.        ,  0.74424552,  0.48849105,  0.23273657,  0.        ])