Behavior of Autocontrast on Normalized Images and Default Value for `contrast_factor`

If we apply autocontrast or RandomAutocontrast on an image with pixel values between 0 and 1, will the resulting image still have pixel values within the range [0,1]? or Should the Image Be Rescaled Again?

What is the default value for contrast_factor in this context? And What is the exact mathematical formula used by the autocontrast function? Is it something like (pixel - min) / (2 * (max - min)) - 1, or is there another formula used?"

Thanks very much!