Recovered linear camera responses and confidence bounds for the (A–B) red, (C–D) green and (E–F) blue channels of a Canon 40D digital camera and; (G–H) the red channel of a Nikon D70s camera modified for ultraviolet recording, using cubic Bézier curves (left column) and biexponential functions(right column).

<p>Linear camera responses were obtained by inverting the biexponential fitting function (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0079534#pone.0079534.e127" target="_blank">Equation 4</a>) (squares) and implementing a look up table derived after evaluating a cubic Bézier curve (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0079534#pone.0079534.e108" target="_blank">Equation 3</a>)(circles). Confidence bounds represent the standard deviation in all cases. Standard deviation of the biexponential function for display purposes.