用于产生 Anchor 值的聚类分析代码，参考于：kmeans-anchor-boxes
仅供归档
# -*- coding=utf-8 -*-
# file name: calcAnchor.py
import glob
import os
import sys
import xml.etree.ElementTree as ET
import numpy as np
from kmeans import kmeans, avg_iou
# 根文件夹，VOC-XML类型的数据集
ROOT_PATH = '/data/DataBase/YOLO_Data/V3_DATA/'
# 聚类的数目
CLUSTERS = 6
# 模型中图像的输入尺寸，默认是一样的
# 用于K210平台上的一般为224（必须为32的整倍数）
SIZE = 224
# 加载YOLO格式的标注数据
def load_dataset(path):
jpegimages = os.path.join(path, 'JPEGImages')
if not os.path.exists(jpegimages):
print('no JPEGImages folders, program abort')
sys.exit(0)
labels_txt = os.path.join(path, 'labels')
if not os.path.exists(labels_txt):
print('no labels folders, program abort')
sys.exit(0)
label_file = os.listdir(labels_txt)
print('label count: {}'.format(len(label_file)))
dataset = []
for label in label_file:
with open(os.path.join(labels_txt, label), 'r') as f:
txt_content = f.readlines()
for line in txt_content:
line_split = line.split(' ')
roi_with = float(line_split[len(line_split)-2])
roi_height = float(line_split[len(line_split)-1])
if roi_with == 0 or roi_height == 0:
continue
dataset.append([roi_with, roi_height])
# print([roi_with, roi_height])
return np.array(dataset)
data = load_dataset(ROOT_PATH)
out = kmeans(data, k=CLUSTERS)
print(out)
print("Accuracy: {:.2f}%".format(avg_iou(data, out) * 100))
print("Boxes:\n {}-{}".format(out[:, 0] * SIZE, out[:, 1] * SIZE))
ratios = np.around(out[:, 0] / out[:, 1], decimals=2).tolist()
print("Ratios:\n {}".format(sorted(ratios)))
label count: 344
[[0.09090909 0.11363636]
[0.10795455 0.1504329 ]
[0.13230519 0.17532468]
[0.21753247 0.22943723]
[0.35064935 0.45238095]
[0.6875 0.66287879]]
Accuracy: 81.42%
Boxes:
[ 20.36363636 24.18181818 29.63636364 48.72727273 78.54545455 154. ]-[ 25.45454545 33.6969697 39.27272727 51.39393939 101.33333333 148.48484848]
Ratios: [0.72, 0.75, 0.78, 0.8, 0.95, 1.04]
可得出 Anchor 参数：[20, 25, 24, 33, 29, 39, 48, 51, 78, 101, 154, 148]
# file name: kmeans.py
import numpy as np
def iou(box, clusters):
"""
Calculates the Intersection over Union (IoU) between a box and k clusters.
:param box: tuple or array, shifted to the origin (i. e. width and height)
:param clusters: numpy array of shape (k, 2) where k is the number of clusters
:return: numpy array of shape (k, 0) where k is the number of clusters
"""
x = np.minimum(clusters[:, 0], box[0])
y = np.minimum(clusters[:, 1], box[1])
if np.count_nonzero(x == 0) > 0 or np.count_nonzero(y == 0) > 0:
raise ValueError("Box has no area")
intersection = x * y
box_area = box[0] * box[1]
cluster_area = clusters[:, 0] * clusters[:, 1]
iou_ = intersection / (box_area + cluster_area - intersection)
return iou_
def avg_iou(boxes, clusters):
"""
Calculates the average Intersection over Union (IoU) between a numpy array of boxes and k clusters.
:param boxes: numpy array of shape (r, 2), where r is the number of rows
:param clusters: numpy array of shape (k, 2) where k is the number of clusters
:return: average IoU as a single float
"""
return np.mean([np.max(iou(boxes[i], clusters)) for i in range(boxes.shape[0])])
def translate_boxes(boxes):
"""
Translates all the boxes to the origin.
:param boxes: numpy array of shape (r, 4)
:return: numpy array of shape (r, 2)
"""
new_boxes = boxes.copy()
for row in range(new_boxes.shape[0]):
new_boxes[row][2] = np.abs(new_boxes[row][2] - new_boxes[row][0])
new_boxes[row][3] = np.abs(new_boxes[row][3] - new_boxes[row][1])
return np.delete(new_boxes, [0, 1], axis=1)
def kmeans(boxes, k, dist=np.median):
"""
Calculates k-means clustering with the Intersection over Union (IoU) metric.
:param boxes: numpy array of shape (r, 2), where r is the number of rows
:param k: number of clusters
:param dist: distance function
:return: numpy array of shape (k, 2)
"""
rows = boxes.shape[0]
distances = np.empty((rows, k))
last_clusters = np.zeros((rows,))
np.random.seed()
# the Forgy method will fail if the whole array contains the same rows
clusters = boxes[np.random.choice(rows, k, replace=False)]
while True:
for row in range(rows):
distances[row] = 1 - iou(boxes[row], clusters)
nearest_clusters = np.argmin(distances, axis=1)
if (last_clusters == nearest_clusters).all():
break
for cluster in range(k):
clusters[cluster] = dist(boxes[nearest_clusters == cluster], axis=0)
last_clusters = nearest_clusters
return clusters本文标题：Yolo Anchor数值 聚类分析
本文连接：https://blog.dextercai.com/archives/52.html
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