1. A computer-implemented method for removing noise from a signal of a target object, the computer-implemented method comprising: receiving an input signal from a source system, the input signal comprising image data identifying a target object and a plurality of parameters, and further comprising a noise portion, wherein the image data is selected from a group consisting of X-ray, CT, emission tomography, SPECT and PET, and the target object comprises image data of a body part of a patient; selecting an initial subset of parameters from the plurality of parameters; estimating a nonparametric probability distribution function (pdf) from the received input signal which comprises a linear combination of functions; generating a quadratic likelihood function (QLF) based on the nonparametric PDF estimated including the linear combination of functions; determining a fit of the initially selected subset of parameters to the data identifying the target object, based on the QLF; in response to the determined fit of the initially selected subset of parameters being below a predetermined threshold, iteratively optimizing parameters by selecting a new subset of parameters from the plurality of parameters and determining a fit of the new subset of parameters, until the determined fit satisfies the predetermined threshold; and generating an output signal comprising a reconstructed signal of the target object constructed using the new subset of iteratively optimized parameters.