The authors gratefully acknowledge the financ1al support of the Higher Education Authority.

Abstract- Fluorescence microscopy imaging is a constant trade off between signal to noise ratio, total observation time and spatio-temporal resolution due to photo toxicity. In this paper, we propose a method to estimate the quality of a fluorescent image acquisition, from a single image, taking into account both signal dependent and signal independent noise. We propose a method for the calculation of the signal to noise ratio globally and locally. We validated our algorithm on real experimental data and data with known simulated noise. Results allow us to conclude that this fully automatic method provides a good quantification of the image quality., where 8 is the signal corrected for background, V is the estimated noise variance, and A, P and M are the variances of the three noise components considered: additive, Poisson and multiplicative noise, respectively. In [4], the estimation of A was considered inaccurate and moreover bad results were obtained when the background value was O. In addition, the parameters fitting was done on times series of 128 images. In general, noise estimation methods follow two different approaches. The first is the smoothing based approach, where the noise is estimated by the difference between the original I