A computer-implemented method for image segmentation, implemented by a computer device, comprising: sequentially selecting a current two dimensional, 2D, image frame according to a time sequence in a video; determining a 2D reference image frame from 2D image frames before the current 2D image frame in the time sequence in the video; obtaining first 2D location information of a target object key point in the 2D reference image frame; performing an affine transformation on the current 2D image frame with reference to an affine transformation relationship between the first 2D location information and a target object key point template, to obtain a 2D target object diagram of the current 2D image frame, wherein the 2D target object diagram is a region of interest, ROI, image of a target object from which unrelated image content of the current 2D image frame has been removed in order to focus processing on the target object, and wherein performing the affine transformation on the current 2D image frame with reference to the affine transformation relationship comprises adjusting 2D location information of the target object key point in the current 2D image frame to preset 2D location information of the target object key point in the target object key point template; performing a 2D key point detection on the 2D target object diagram, to obtain second 2D location information of the target object key point; segmenting a target object from the 2D target object diagram, to obtain segmentation information of the target object; and obtaining the target object through segmentation from the current 2D image frame according to the segmentation information and the second 2D location information and based on performing a mapping from the 2D target object diagram to the current 2D image frame. sequentially selecting a current two dimensional, 2D, image frame according to a time sequence in a video; determining a 2D reference image frame from 2D image frames before the current 2D image frame in the time sequence in the video; obtaining first 2D location information of a target object key point in the 2D reference image frame; performing an affine transformation on the current 2D image frame with reference to an affine transformation relationship between the first 2D location information and a target object key point template, to obtain a 2D target object diagram of the current 2D image frame, wherein the 2D target object diagram is a region of interest, ROI, image of a target object from which unrelated image content of the current 2D image frame has been removed in order to focus processing on the target object, and wherein performing the affine transformation on the current 2D image frame with reference to the affine transformation relationship comprises adjusting 2D location information of the target object key point in the current 2D image frame to preset 2D location information of the target object key point in the target object key point template; performing a 2D key point detection on the 2D target object diagram, to obtain second 2D location information of the target object key point; segmenting a target object from the 2D target object diagram, to obtain segmentation information of the target object; and obtaining the target object through segmentation from the current 2D image frame according to the segmentation information and the second 2D location information and based on performing a mapping from the 2D target object diagram to the current 2D image frame.