SSD 的Default box /prior box生成原理

Default box 超参数设定：

mbox_source_layers = ['conv4_3', 'fc7','conv6_2', 'conv7_2', 'conv8_2', 'conv9_2'] //多尺寸检测

min_ratio = 20 

max_ratio = 90

step = int(math.floor((max_ratio -min_ratio) / (len(mbox_source_layers) - 2))) //17

min_sizes = []  //none

max_sizes = []  //none

for ratio in xrange(min_ratio, max_ratio +1, step):

 min_sizes.append(min_dim * ratio / 100.)  //[60,111,162,213,264]

 max_sizes.append(min_dim * (ratio + step) / 100.)  //[111,162,213,264,315]

min_sizes = [min_di