Image of A Simple Object: Knife Covered with Cloth

Let us start by using a more formal approach on the images in Figure: Concealed Knife . Goodman's criteria for the independence of the speckle patterns also concludes that of the 41 images taken across 41⁰ there are 16 independent illumination angles. An image that is the average of many speckle patterns will have an intensity distribution that follows a gamma density function of order $N$, \begin{equation}p_I(I)=\frac{N^N I^{N-1}}{\Gamma (N)\langle I \rangle^N}e^{-N\frac{I}{\langle I \rangle}}\end{equation}