quick-and-dirty hog

HoG.py

def hog(mag, angle, bin_dist=20):
    h, w = mag.shape
    
    bins = defaultdict(lambda: 0)
    
    locs1 = (np.floor(angle / bin_dist) * bin_dist).astype(int)
    locs2 = locs1 + bin_dist
    
    ihs = (angle - locs1) / bin_dist
    ils = 1 - ihs
    
    il_m = ils * mag
    ih_m = ihs * mag
    
    for i in range(h):
        for j in range(w):
            bins[locs1[i,j] % 180] += il_m[i,j]
            bins[locs2[i,j] % 180] += ih_m[i,j]
            
    return sorted(bins.items(), key=lambda k: k[1])