A medical imaging system and an image processing method for producing an optimized image from an input image are provided. The medical imaging system comprises: a parameter accumulator configured to accumulate a preset number of basic parameters; a parameter determiner configured to produce new reference parameters based on current reference parameters and the accumulated basic parameters to replace the current reference parameters with the new reference parameters; an image processor configured to process an input image to generate an optimized image according to an image processing algorithm based on the reference parameters sent from the parameter determiner; and a controller configured to control overall operation of the medical imaging system.