高斯核

import numpy as np
def draw_gauss(heatmap, x, y, gsize):
    
    height, width = heatmap.shape[:2]
    gsize += 1 - (gsize % 2)
    sigma = gsize / 6
    s = 2 * sigma * sigma
    radius = gsize // 2
    ky, kx = np.ogrid[-radius:+radius+1, -radius:+radius+1]
    kernel = np.exp(-(kx * kx + ky * ky) / s)
    
    dleft, dtop = -min(x, radius), -min(y, radius)
    dright, dbottom = +min(width - x, radius+1), +min(height - y, radius+1)
    select_heatmap = heatmap[y+dtop:y+dbottom, x+dleft:x+dright]
    select_kernel = kernel[radius+dtop:radius+dbottom, radius+dleft:radius+dright]
    if min(select_heatmap.shape) > 0:
        np.maximum(select_heatmap, select_kernel, out=select_heatmap)
    return heatmap