Adding poisson noise to an image

Question

I have some images that I need to add incremental amounts of Poisson noise to in order to more thoroughly analyze them. I know you can do this in MATLAB, but how do you go a

Answer 1

Actually the answer of Paul doesnt make sense.

Poisson noise is signal dependent! And using those commands, provided by him, the noise later added to the image is not signal dependent.

To make it signal dependent you shold pass the image to the NumPy's poisson function:

filename = 'myimage.png'
img = (scipy.misc.imread(filename)).astype(float)

noise_mask = numpy.random.poisson(img)

noisy_img = img + noise_mask