今天在做一个图像检索系统的Demo演示时需要用到一个比较大的数据库，查看了一下手头的几个数据库，决定选用Caltech 101。Caltech 101有102类，在101_ObjectCategories文件夹下有102个文件夹，而每一个文件夹下的图像文件名都是以image_0xxx.jpg`这种方式命名的，如果一个个的把它们搬出来的话，不仅重名而且还费时费力。因为对python比较熟悉，知道这事用python来完成肯定不怎么难，费了10来分钟，写了个脚本，圆满的完成了任务。写完再搜Caltech 101链接的时候，发现已有人对这个问题做了处理，详见这里。大致瞄了几眼，感觉跟自己下面用python写的相比，写的好复杂。
101_ObjectCategories的目录结构如下:
willard@willard-PC~/Pictures/101_ObjectCategories $ tree -L 2
.
├── anchor
│ ├── image_0001.jpg
│ ├── image_0002.jpg
│ └── image_0003.jpg
├── ant
│ ├── image_0001.jpg
│ ├── image_0002.jpg
│ └── image_0003.jpg
└── ......
├── image_0001.jpg
├── image_0002.jpg
└── ......
```sh
要把上面的图像放在一起,并加上所属的类别名,即w为下面这种形式:
```sh
willard@willard-PC~/Pictures/101_ObjectCategories $ tree -L 1
.
├── anchor_image_0001.jpg
├── anchor_image_0002.jpg
├── anchor_image_0003.jpg
├── ant_image_0001.jpg
├── ant_image_0002.jpg
├── ant_image_0003.jpg
├── binocular_image_0001.jpg
├── binocular_image_0002.jpg
└── ......
脚本如下:
import os
from re import sub
import fnmatch
# walk through the folder
f = open("./101_ObjectCategories/101_ObjectCategories.txt", "w")
for root, dirs, files in os.walk('101_ObjectCategories'):
for str_each_folder in dirs:
# we get the directory path
str_the_path = '/'.join([root, str_each_folder])
files_number = len(fnmatch.filter(os.listdir(str_the_path), '*.jpg'))
# list all the files using directory path
for str_each_file in os.listdir(str_the_path):
# look for the files we want
if str_each_file.endswith('.jpg'):
# now add the new one
str_new_name = str_each_folder + '_' + str_each_file
# full path for both files
str_old_name = '/'.join([str_the_path, str_each_file])
str_new_name = '/'.join([root, str_new_name])
# now rename using the two above strings
# and the full path to the files
os.rename(str_old_name, str_new_name)
# we can print the folder name so we know
# that all files in the folder are done
print '%s, %d images' % (str_each_folder, files_number)
f.writelines('%s, %d images\n' % (str_each_folder, files_number))
f.close
在完成重命名后将图像搬移到上一级，并将该文件夹名称及其有多少幅图像保存在101_ObjectCategories.txt中。顺便吐槽一下，Windows下tree命令真烂。
