how to get this mask

[xilinniao123]

thanks for sharing! about the code snip ,why you get mask in this way?? can you give some explanation??

for y in range(hist_size//2):
             hist_mask['Pedestrian'][y, :hist_size//8*3-y*3//4] = 0
             hist_mask['Pedestrian'][y, hist_size//8*5+y*3//4:] = 0
             hist_mask['Pedestrian'][hist_size//2+y, :y*3//4] = 0
             hist_mask['Pedestrian'][hist_size//2+y, hist_size-y*3//4:] = 0
for y in range(hist_size//4):\n
             hist_mask['Car'][y, :hist_size//4-y] = 0
             hist_mask['Car'][y, hist_size//4*3+y:] = 0
             hist_mask['Car'][hist_size//4*3+y, :y] = 0
             hist_mask['Car'][hist_size//4*3+y, hist_size-y:] = 0