I may be able to help.  Could you please provide more info on what you're trying to do?

Thanks for your response,

I need to add noises in the image both Poisson-Gaussian (that is mixed Poisson-Gaussian). But, how to add these noises is my doubt.

Original image + Poisson + Gaussian

Or

Original image + Gaussian + Poisson

Or

(Original Image + Poisson) + (Original image + Gaussian)

Please clarify the steps to add mixed Poisson-Gaussian noise.

Thank You

Attached is a MATLAB script which adds shot noise (Poisson noise) and read noise (Gaussian noise) to an image.  You can change the SNR by changing the simulated quantum well depth of the sensor or the standard deviation of the read noise.  I hope this helps.   

Milo Hyde Thanks for your code. I get a question here, could I apply your code to l depth image?