Brightness analysis

This module contains function to evaluate the brightness of an image. It includes a converter for sRGB to RGB, evaluation of relative luminance according to BT.709 and BT.601

@author: Giulio Gabrieli

brightness.relativeLuminance_BT601(img)

This function evaluates the brightness of an image by mean of Y, where Y is evaluated as:

Y = 0.587G + 0.114B + 0.299R B = mean(Y)

Parameters:img (numpy.ndarray) – image to analyze, in RGB Returns:mean brightness Return type:float

brightness.relativeLuminance_BT709(img)

This function evaluates the brightness of an image by mean of Y, where Y is evaluated as:

Y = 0.7152G + 0.0722B + 0.2126R B = mean(Y)

Parameters:img (numpy.ndarray) – image to analyze, in RGB Returns:mean brightness Return type:float

brightness.sRGB2RGB(img)

this function converts a sRGB img to linear RGB values.

It loops through each pixel, and apply a conversion to pass from sRGB to linear RGB value.

Parameters:img (numpy.ndarray) – image to analyze, in sRGB Returns:image to analyze, in RGB Rtyipe:numpy.ndarray