How the Saturated Pixels violate the assumption that the image formation process in linear? I am working in digital image restoration field and i have studied this is many research papers that presence of saturated pixels violates the assumption which is initially assumed by many blind deconvolution algorithms, that the image formation process is linear...

Can anyone please explain that how this rule is violated.?
Blind deconvolution assumes that the blurred image is the result of distorting the original image by convolution. Convolution is a linear process, i.e. the image is just a sum of shifted and scaled versions of the original image. Pixel saturation, on the other hand, is a non-linear process, which cannot be modeled by convolution. Consequently, it cannot be handled by conventional blind deconvolution techniques. Also note that saturation is irreversible, i.e. once a quantity is saturated its original value cannot be recovered.