colour_hdri.image_stack_to_radiance_image(image_stack, weighting_function=<function weighting_function_Debevec1997>, weighting_average=False, camera_response_functions=None)[source]

Generates a HDRI / radiance image from given image stack.

  • image_stack (colour_hdri.ImageStack) – Stack of single channel or multi-channel floating point images. The stack is assumed to be representing linear values except if camera_response_functions argument is provided.
  • weighting_function (callable, optional) – Weighting function \(w\).
  • weighting_average (bool, optional) – Enables weighting function \(w\) computation on channels average instead of on a per channel basis.
  • camera_response_functions (array_like, optional) – Camera response functions \(g(z)\) of the imaging system / camera if the stack is representing non linear values.

Radiance image.

Return type:



If the image stack contains images with negative or equal to zero values, unpredictable results may occur and NaNs might be generated. It is thus recommended to encode the images in a wider RGB colourspace or clamp negative values.