The disclosure relates to a system and method for generating or using a synthesizing filter in image reconstruction. The method may include: acquiring a calibration data set including a plurality of data points, determining a first calibration region in the calibration data set, the first calibration region including a matrix having a plurality of data points, the plurality of data points includes a first data point at the center of the first calibration region, constructing a first relationship between the first data point and the data points in the first calibration region, and generating a synthesizing filter based on the first relationship. The first data point is at the center of the first calibration region. The method may be implemented on at least one machine each of which has at least one processor and storage. The generated synthesizing filter may be stored in the storage in electronic form as a data file. The synthesizing filter may be adapted for determining an unknown data point in an undersampled k-space data set based on a signal acquired by the receiver coil.