Image segmentation method and electronic device

An electronic device having an image segmentation function, comprising an image sensor and a processor, wherein

• the image sensor is configured to obtain a first gray-scale image towards a target area;
• and
• the processor is coupled to the image sensor and is configured to execute the following operations:
• performing regression analysis on the first gray-scale image to obtain a residual image, and determining an object backbone area of the residual image;
• calculating an average gray-scale value of the object backbone area in the residual image to define a pixel value of each pixel in the object backbone area as the average gray-scale value, and generating a second gray-scale image having the object backbone area;
• recursively determining whether a residual polarity of each of a plurality of adjacent pixels adjacent to a plurality of edge pixels of the object backbone area in the residual image is the same as a residual polarity of the corresponding edge pixel, and whether a pixel value of each of the plurality of adjacent pixels in the residual image is greater than a respectively corresponding first threshold, so as to expand the object backbone area in the second gray-scale image;
• and extracting the object backbone area in the second gray-scale image subjected to the recursive determination as a target object in the target area.