用Tesseract训练验证码遇到的问题

1.准备验证码图片

 import os
 from urllib.request import urlretrieve

 urlPath='http://www.189.cn/portal/captcha/simple.do?date=1503125232339'
 localPath='G:\python_work\chapter11\captcha'

 # 根据文件名创建文件
 def createFileByFileName(localPath,fileName):
     if not os.path.exists(localPath):
         os.makedirs(localPath)
     totalPath=localPath+'\\'+fileName
     if not os.path.exists(totalPath):
         file=open(totalPath, 'a+')
         file.close()
         return totalPath

 # 根据图片的地址, 下载图片并保存在本地
 def getAndSaveImg(imgUrl, filename):
     if(len(imgUrl)!=0):
         file=filename+'.jpg'
         urlretrieve(imgUrl, createFileByFileName(localPath, file))

 # 下载图片
 i=0
 while i<100:
     getAndSaveImg(urlPath, str(i))
     i=i+1

2.将验证码图片转为灰度图 , 扩展名改为.tif

 import os
 from PIL import Image

 def getFileList(path):
     # 返回目录中所有jpg图像的文件名列表
     return [os.path.join(path, f) for f in os.listdir(path) if f.endswith('.jpg')]

 # 批量将图片转为灰度图
 def patchConvert(srcPath, destPath):
     fileList = getFileList(srcPath)
     for file in fileList:
         img = Image.open(file).convert('L')
         name_ext = getFileNameAndExt(file)
         destFile = os.path.join(destPath, name_ext[0]+'.tif')
         img.save(destFile)

 # 获取文件名和扩展名
 def getFileNameAndExt(filename):
     # 取目录与文件名
     (filepath, tempfilename) = os.path.split(filename)
     # 取文件名(不带扩展名)和扩展名
     (shotname, extension) = os.path.splitext(tempfilename)
     return shotname, extension

 patchConvert('captcha', 'captcha_gray')

3. 后续步骤参考原先的博客:

http://www.cnblogs.com/CoolJayson/p/7395824.html

问题: 生成box文件后, 用jTessBoxEditor修改box文件时, 里面的矩形画的误差较大, 字符个数识别不准确 , 应该如何对矩形进行修改???