Renaming .jpg files in the sub-folders - bash

Question

I have a large number of files in sub-folders that I need to rename. For example, I have:
ParentFolder/sub-Folders/*.jpg
How can I copy the files with a new naming convention as follows?
ParentFolder1.jpg
ParentFolder2.jpg

Answer 1

One way to do this is via GNU parallel. Tutorial here:
find ./ParentFolder -name "*.jpg" | parallel "mv {} DESTINATION/ParentFolder{#}.jpg"
To view the commands to be run before executing them, try:
find ./ParentFolder -name "*.jpg" | parallel --dryrun "mv {} DESTINATION/ParentFolder{#}.jpg"

Answer 2

Use rename over the full path using file globbing :
*/*
If you don't understand, you can test it with :
echo */*
First * is your directory, second * is your file name. Catch them in a regular expression :
(.*)/(.*)
Now $1 is your parent folder name and $2 is your file name. You can easily build your solution like this :
rename -n "s/(.*)\/(.*)/\$1\/\$1\$2/" */*
It keeps directory structure and adds directory name as a prefix to each of its files. You could move your files up by simply changing \$1\/\$1\$2 to \$1\$2. You then just have to delete empty directories using rmdir.
I voluntarily added the option -n so you don't do a mess if you copy-paste. Simply remove the option when you think it's good.
adrien#adrienLT:~/Documents/PEV$ cp -r Holiday/ Holiday_copy/
adrien#adrienLT:~/Documents/PEV$ tree Holiday*
Holiday
├── France
│   ├── 1.jpg
│   ├── 2.jpg
│   └── 3.jpg
├── Italy1
│   ├── 1.jpg
│   ├── 2.jpg
│   └── 3.jpg
└── Italy2
├── 1.jpg
├── 2.jpg
└── 3.jpg
Holiday_copy
├── France
│   ├── 1.jpg
│   ├── 2.jpg
│   └── 3.jpg
├── Italy1
│   ├── 1.jpg
│   ├── 2.jpg
│   └── 3.jpg
└── Italy2
├── 1.jpg
├── 2.jpg
└── 3.jpg
6 directories, 18 files
adrien#adrienLT:~/Documents/PEV$ cd Holiday_copy/
adrien#adrienLT:~/Documents/PEV/Holiday_copy$ rename "s/(.*)\/(.*)/\$1\/\$1\$2/" */*
adrien#adrienLT:~/Documents/PEV/Holiday_copy$ tree .
.
├── France
│   ├── France1.jpg
│   ├── France2.jpg
│   └── France3.jpg
├── Italy1
│   ├── Italy11.jpg
│   ├── Italy12.jpg
│   └── Italy13.jpg
└── Italy2
├── Italy21.jpg
├── Italy22.jpg
└── Italy23.jpg
3 directories, 9 files