The speckle noise in ultrasound images reduces image resolution and contrast

and brings difficulty to subsequent image processing.Based on MAP (Maximum A Posteriori)

the paper proposes an ultrasound image decomposition method

to decompose an observed image into a speckle-free true image and a speckle image.We use Field II to simulate an ultrasound image

and decompose it with the proposed method.By six tests with different parameters

we study how the weighted parameters influence the decomposition results.Then we use this method to decompose three real ultrasound images.The true image we get by decomposition can be seen as the denoised image

because it has good homogeneity

and preserves details and edges well.Both the true image and the speckle can be used in feature extraction

image segmentation

classification and so on.