BW = imbinarize(im2gray(imread('https://www.mathworks.com/matlabcentral/answers/uploaded_files/1200303/image.jpeg')));
[row,col] = find(BW); % 白い点の座標だけ抜き出す
row = row(1:30:end); % 間引く
col = col(1:30:end); % 間引く
row = [row; (spline(col,row,800:30:size(BW,2)))']; % 外挿
col = [col; (800:30:size(BW,2))']; % 外挿
scatter(col,row,1);
ふざけていません本気です🤔