[Ian Robinson]

A little more detail : from my old signal processing notes-

A blurred or degraded image can be approximately described by this equation g = Hf + n,
where
g is the blurred image
H is the distortion operator, also called the point spread
function (PSF)
f is the original true image and
n is Additive noise, introduced during image acquisition, that corrupts the image.

In the spatial domain, the PSF describes the degree to which an optical system blurs (spreads) a point of light. The PSF is the inverse Fourier transform of the optical transfer function (OTF). In the frequency
domain, the OTF describes the response of a linear, position-invariant system to an impulse. The OTF is the Fourier transform of the point spread function (PSF). The distortion operator, when convolved with the image, creates the distortion. Distortion caused by a point spread function is just one type of distortion.

So you need to subtract n.
and then you deconvolveit.

The syntax is [q,r] = deconv(b,a) where b and a arrays and the results are matrix [q,r] = [g]-[n].

The rest is easy codingwize , just need to assign an acceptable n and H. How do you do that someone asks - a curvefit will do it , that will give you H and n. (Easy to do in Matlab).