An ultrasound system, comprising: an ultrasound data acquisition unit configured to transmit and receive ultrasound signals to and from a target object based on a plurality of steering angles to thereby output a plurality of ultrasound data for obtaining a plurality of ultrasound images corresponding to the steering angles; and a processing unit in communication with the ultrasound data acquisition unit, the processing unit being configured to form the ultrasound images based on the ultrasound data, decompose each of the ultrasound images into a low pass image having a low frequency component and a high pass image having a high frequency component to thereby output a plurality of low pass images and a plurality of high pass images, perform a pairwise blending process upon the plurality of low pass images and the plurality of high pass images to thereby output a plurality of blended low pass images and a plurality of blended high pass images, form a plurality of restoration images by composing the blended low pass images and the blended high pass images, and form an ultrasound spatial compound image based on the restoration images, whereby the processing unit is configured to perform the blending process by detecting first boundary lines of the low pass images and second boundary lines of the high pass images, setting first blending areas having a predetermined size on the low pass images based on the first boundary lines and second blending areas having the predetermined size on the high pass images based on the second boundary lines, and performing the blending process upon the low pass images and the high pass images based on the first blending areas and the second blending areas. an ultrasound data acquisition unit configured to transmit and receive ultrasound signals to and from a target object based on a plurality of steering angles to thereby output a plurality of ultrasound data for obtaining a plurality of ultrasound images corresponding to the steering angles; and a processing unit in communication with the ultrasound data acquisition unit, the processing unit being configured to form the ultrasound images based on the ultrasound data, decompose each of the ultrasound images into a low pass image having a low frequency component and a high pass image having a high frequency component to thereby output a plurality of low pass images and a plurality of high pass images, perform a pairwise blending process upon the plurality of low pass images and the plurality of high pass images to thereby output a plurality of blended low pass images and a plurality of blended high pass images, form a plurality of restoration images by composing the blended low pass images and the blended high pass images, and form an ultrasound spatial compound image based on the restoration images, whereby the processing unit is configured to perform the blending process by detecting first boundary lines of the low pass images and second boundary lines of the high pass images, setting first blending areas having a predetermined size on the low pass images based on the first boundary lines and second blending areas having the predetermined size on the high pass images based on the second boundary lines, and performing the blending process upon the low pass images and the high pass images based on the first blending areas and the second blending areas.