A method for obtaining an image mask, the method comprising: obtaining a magnitude image and a phase image of a to-be-processed image; performing homodyne high-pass filtering on the phase image; obtaining magnitude coherent data of each pixel point in the magnitude image by performing average filtering or low-pass calculation for coherent data of each pixel point in the magnitude image within a preset range from the pixel point, and obtaining phase coherent data of each pixel point in the phase image by performing calculating for coherent data of each pixel point in the phase image within the preset range from the pixel point; obtaining a magnitude image mask by performing binarization threshold processing on the magnitude coherent data of each pixel point in the magnitude image, and obtaining a phase image mask by performing binarization threshold processing on the phase coherent data of each pixel point in the phase image; and obtaining an image mask for the to-be-processed image by using the magnitude image mask and the phase image mask; wherein calculating the coherent data of each pixel point in the phase image within the preset range from the pixel point comprises: calculating the phase coherent data Q e, f, g VPH of a pixel point (e, f, g) in the phase image according to a following formula: Q e, f, g VPH = 1 α VPH 1 − 1 d x d y d z ∑ r = e − d x − 1 2 r = e + d x − 1 2 ∑ s = f − d y − 1 2 s = f + d y − 1 2 ∑ t = g − d z − 1 2 t = g + d z − 1 2 p ^ r, s, t p ^ r, s, t + 1; wherein, Q e, f, g VPH denotes the phase coherent data of the pixel point (e, f, g) in the phase image, α VPH denotes a normalization constant, d x,d y,d z respectively denote values in direction x, direction y and direction z within the preset range, wherein direction z is perpendicular to a plane in which direction x and direction y locate, and p ^ r, s, t p ^ r, s, t denotes a phase of a pixel point (r, s, t) in the phase image, r ∈ e − d x − 1 2, e + d x − 1 2, s ∈ f − d y − 1 2, f + d y − 1 2, t ∈ g − d z − 1 2, g + d z − 1 2. obtaining a magnitude image and a phase image of a to-be-processed image; performing homodyne high-pass filtering on the phase image; obtaining magnitude coherent data of each pixel point in the magnitude image by performing average filtering or low-pass calculation for coherent data of each pixel point in the magnitude image within a preset range from the pixel point, and obtaining phase coherent data of each pixel point in the phase image by performing calculating for coherent data of each pixel point in the phase image within the preset range from the pixel point; obtaining a magnitude image mask by performing binarization threshold processing on the magnitude coherent data of each pixel point in the magnitude image, and obtaining a phase image mask by performing binarization threshold processing on the phase coherent data of each pixel point in the phase image; and obtaining an image mask for the to-be-processed image by using the magnitude image mask and the phase image mask; wherein calculating the coherent data of each pixel point in the phase image within the preset range from the pixel point comprises: calculating the phase coherent data Q e, f, g VPH of a pixel point (e, f, g) in the phase image according to a following formula: Q e, f, g VPH = 1 α VPH 1 − 1 d x d y d z ∑ r = e − d x − 1 2 r = e + d x − 1 2 ∑ s = f − d y − 1 2 s = f + d y − 1 2 ∑ t = g − d z − 1 2 t = g + d z − 1 2 p ^ r, s, t p ^ r, s, t + 1; wherein, Q e, f, g VPH denotes the phase coherent data of the pixel point (e, f, g) in the phase image, α VPH denotes a normalization constant, d x,d y,d z respectively denote values in direction x, direction y and direction z within the preset range, wherein direction z is perpendicular to a plane in which direction x and direction y locate, and p ^ r, s, t p ^ r, s, t denotes a phase of a pixel point (r, s, t) in the phase image, r ∈ e − d x − 1 2, e + d x − 1 2, s ∈ f − d y − 1 2, f + d y − 1 2, t ∈ g − d z − 1 2, g + d z − 1 2. wherein, Q e, f, g VPH denotes the phase coherent data of the pixel point (e, f, g) in the phase image, α VPH denotes a normalization constant, d x,d y,d z respectively denote values in direction x, direction y and direction z within the preset range, wherein direction z is perpendicular to a plane in which direction x and direction y locate, and p ^ r, s, t p ^ r, s, t denotes a phase of a pixel point (r, s, t) in the phase image, r ∈ e − d x − 1 2, e + d x − 1 2, s ∈ f − d y − 1 2, f + d y − 1 2, t ∈ g − d z − 1 2, g + d z − 1 2.