目标检测中数据增强的方法——mixup：针对小样本
目标检测中数据增强的方法——mixup：针对小样本
在样本量不足的情况下，我们通常会采用mixup或者填鸭式的方法来进行数据增强。其中mixup是将正负样本融合成新的一组样本，使得样本量翻倍。填鸭式是将原本样本里的目标抠出来，随机复制粘贴到其他地方。（个人理解）
一下是mixup方法的代码示例
import cv2
import os
import random
import numpy as np
import xml.etree.ElementTree as ET
import xml.dom.minidom
img_path = '...'
save_path = '...'
xml_path = '...'
save_xml = '...'
img_names = os.listdir(img_path)
img_num = len(img_names)
print('img_num:',img_num)
for imgname in img_names:
imgpath = img_path + imgname
img = cv2.imread(imgpath)
img_h, img_w = img.shape[0], img.shape[1]
i = random.randint(0,img_num-1)
print('i:',i)
add_path = img_path + img_names[i]
addimg = cv2.imread(add_path)
add_h, add_w = addimg.shape[0], addimg.shape[1]
if add_h != img_h or add_w != img_w:
print('resize!')
addimg = cv2.resize(addimg, (img_w,img_h), interpolation=cv2.INTER_LINEAR)
scale_h, scale_w = img_h/add_h, img_w/add_w
lam = np.random.beta(0.5, 0.5)
mixed_img = lam*img + (1-lam)*addimg
save_img = save_path + imgname[:-4] + '_3.jpg'
cv2.imwrite(save_img,mixed_img)
print(save_img)
if imgname != img_names[i]:
xmlfile1 = xml_path + imgname[:-4] + '.xml'
xmlfile2 = xml_path + img_names[i][:-4] + '.xml'
tree1 = ET.parse(xmlfile1)
tree2 = ET.parse(xmlfile2)
doc = xml.dom.minidom.Document()
root = doc.createElement("annotation")
doc.appendChild(root)
nodeframe = doc.createElement("frame")
nodeframe.appendChild(doc.createTextNode(imgname[:-4]+'_3'))
objects = []
for obj in tree1.findall("object"):
obj_struct = {}
obj_struct["name"] = obj.find("name").text
# obj_struct["pixelcolor"] = obj.find("pixelcolor").text
# obj_struct["difficult"] = obj.find("difficult").text
bbox = obj.find("bndbox")
obj_struct["bbox"] = [int(bbox.find("xmin").text) ,
int(bbox.find("ymin").text) ,
int(bbox.find("xmax").text) ,
int(bbox.find("ymax").text) ]
objects.append(obj_struct)
for obj in tree2.findall("object"):
obj_struct = {}
obj_struct["name"] = obj.find("name").text
# obj_struct["pixelcolor"] = obj.find("pixelcolor").text
# obj_struct["difficult"] = obj.find("difficult").text
bbox = obj.find("bndbox")
obj_struct["bbox"] = [int(int(bbox.find("xmin").text)*scale_w) ,
int(int(bbox.find("ymin").text)*scale_h) ,
int(int(bbox.find("xmax").text)*scale_w) ,
int(int(bbox.find("ymax").text)*scale_h) ]
objects.append(obj_struct)
for obj in objects:
nodeobject = doc.createElement("object")
nodename = doc.createElement("name")
# nodepixelcolor = doc.createElement("pixelcolor")
# nodedifficult = doc.createElement("difficult")
nodebndbox = doc.createElement("bndbox")
nodexmin = doc.createElement("xmin")
nodeymin = doc.createElement("ymin")
nodexmax = doc.createElement("xmax")
nodeymax = doc.createElement("ymax")
nodename.appendChild(doc.createTextNode(obj["name"]))
# nodepixelcolor.appendChild(doc.createTextNode(obj["pixelcolor"]))
# nodedifficult.appendChild(doc.createTextNode(obj["difficult"]))
nodexmin.appendChild(doc.createTextNode(str(obj["bbox"][0])))
nodeymin.appendChild(doc.createTextNode(str(obj["bbox"][1])))
nodexmax.appendChild(doc.createTextNode(str(obj["bbox"][2])))
nodeymax.appendChild(doc.createTextNode(str(obj["bbox"][3])))
nodebndbox.appendChild(nodexmin)
nodebndbox.appendChild(nodeymin)
nodebndbox.appendChild(nodexmax)
nodebndbox.appendChild(nodeymax)
nodeobject.appendChild(nodename)
# nodeobject.appendChild(nodepixelcolor)
# nodeobject.appendChild(nodedifficult)
nodeobject.appendChild(nodebndbox)
root.appendChild(nodeobject)
fp = open(save_xml + imgname[:-4] + "_3.xml","w")
doc.writexml(fp, indent='\t', addindent='\t', newl='\n', encoding="utf-8")
fp.close()
else:
xmlfile1 = xml_path + imgname[:-4] + '.xml'
tree1 = ET.parse(xmlfile1)
doc = xml.dom.minidom.Document()
root = doc.createElement("annotation")
doc.appendChild(root)
nodeframe = doc.createElement("frame")
nodeframe.appendChild(doc.createTextNode(imgname[:-4]+'_3'))
objects = []
for obj in tree1.findall("object"):
obj_struct = {}
obj_struct["name"] = obj.find("name").text
# obj_struct["pixelcolor"] = obj.find("pixelcolor").text
# obj_struct["difficult"] = obj.find("difficult").text
bbox = obj.find("bndbox")
obj_struct["bbox"] = [int(bbox.find("xmin").text) ,
int(bbox.find("ymin").text) ,
int(bbox.find("xmax").text) ,
int(bbox.find("ymax").text) ]
objects.append(obj_struct)
for obj in objects:
nodeobject = doc.createElement("object")
nodename = doc.createElement("name")
# nodepixelcolor = doc.createElement("pixelcolor")
# nodedifficult = doc.createElement("difficult")
nodebndbox = doc.createElement("bndbox")
nodexmin = doc.createElement("xmin")
nodeymin = doc.createElement("ymin")
nodexmax = doc.createElement("xmax")
nodeymax = doc.createElement("ymax")
nodename.appendChild(doc.createTextNode(obj["name"]))
# nodepixelcolor.appendChild(doc.createTextNode(obj["pixelcolor"]))
# nodedifficult.appendChild(doc.createTextNode(obj["difficult"]))
nodexmin.appendChild(doc.createTextNode(str(obj["bbox"][0])))
nodeymin.appendChild(doc.createTextNode(str(obj["bbox"][1])))
nodexmax.appendChild(doc.createTextNode(str(obj["bbox"][2])))
nodeymax.appendChild(doc.createTextNode(str(obj["bbox"][3])))
nodebndbox.appendChild(nodexmin)
nodebndbox.appendChild(nodeymin)
nodebndbox.appendChild(nodexmax)
nodebndbox.appendChild(nodeymax)
nodeobject.appendChild(nodename)
# nodeobject.appendChild(nodepixelcolor)
# nodeobject.appendChild(nodedifficult)
nodeobject.appendChild(nodebndbox)
root.appendChild(nodeobject)
fp = open(save_xml + imgname[:-4] + "_3.xml","w")
doc.writexml(fp, indent='\t', addindent='\t', newl='\n', encoding="utf-8")
fp.close()