Recursively compressing images in a folder-structure, preserving the folder-structure - linux

Question

I have this folder-strucutre, with really heavy high-quality images in each subfolder
tree -d ./
Output:
./
├── 1_2dia-pedro
├── 3dia-pedro
│   ├── 101MSDCF
│   └── 102MSDCF
├── 4dia-pedro
└── Wagner
├── 410_0601
├── 411_0701
├── 412_0801
├── 413_2101
├── 414_2801
├── 415_0802
├── 416_0902
├── 417_1502
├── 418_1602
├── 419_1702
├── 420_2502
└── 421_0103
18 directories
And, I want to compress it, just like I would do with ffmpeg, or imagemagick.
e.g.,
ffmpeg -i %%F -q:v 10 processed/%%F"
mogrify -quality 3 $F.png
I'm currently think of creating a vector of the directories, using shopt, as discussed here
shopt -s globstar dotglob nullglob
printf '%q\n' **/*/
Then, create a new folder-compressed, with the same structure
mkdir folder-compressed
<<iterate the array-vector-out-of-shopt>>
Finally, compress, for each subfolder, something in the lines of
mkdir processed
for f in *.jpg;
do ffmpeg -i "$f" -q:v 1 processed/"${f%.jpg}.jpg";
done
Also, I read this question, and this procedure seems close to what I would like,
for f in mydir/**/*
do
# operations here
done
Major problem: I'm bash newbie. I know all tools needed are at my disposal!
EDIT: There is a program that, for the particular purpose of compressing images with lossless quality, gives us a a-liner, and a lot of options to this compression. The caveat: make another copy of the original folder-structure-files, because it will change them permanently in the folder-structure-files you give it.
cp -r ./<folder-structure-files> ./<folder-structure-files-copy>
image_optim -r ./<folder-structure-files-copy>
I think #m0hithreddy solution is pretty cool, though. Certainly, I will be using that logic elsewhere anytime soon.

Answer 1

Instead of pre-mkdiring directories, you can create the required directories on the fly. Recursion solutions look elegant to me then compared to loops. Here is a straight-forward approach. I echoed the file names and directories to keep track of whats going on. I am not ffmpeg pro, I used cp instead but should work fine for your use case.
Shell script:
source=original/
destination=compressed/
f1() {
mkdir -p ${destination}${1}
for file in `ls ${source}${1}*.jpg 2>/dev/null`
do
echo 'Original Path:' ${file}
echo 'Compressed Path:' ${destination}${1}$(basename $file) '\n'
cp ${file} ${destination}${1}$(basename $file)
done
for dir in `ls -d ${source}${1}*/ 2>/dev/null`
do
echo 'Enter sub-directory:' ${dir} '\n'
f1 ${dir#*/}
done
}
f1 ''
Terminal Session:
$ ls
original script.sh
$ tree original/
original/
├── f1
│   ├── f16
│   │   └── f12.jpg
│   ├── f5
│   │   └── t4.jpg
│   └── t3.txt
├── f2
│   └── t5.txt
├── f3
├── f4
│   └── f10
│   ├── f2
│   │   └── f6.jpg
│   └── f3.jpg
├── t1.jpg
└── t2.txt
8 directories, 8 files
$ sh script.sh
Original Path: original/t1.jpg
Compressed Path: compressed/t1.jpg
Enter sub-directory: original/f1/
Enter sub-directory: original/f1/f16/
Original Path: original/f1/f16/f12.jpg
Compressed Path: compressed/f1/f16/f12.jpg
Enter sub-directory: original/f1/f5/
Original Path: original/f1/f5/t4.jpg
Compressed Path: compressed/f1/f5/t4.jpg
Enter sub-directory: original/f2/
Enter sub-directory: original/f3/
Enter sub-directory: original/f4/
Enter sub-directory: original/f4/f10/
Original Path: original/f4/f10/f3.jpg
Compressed Path: compressed/f4/f10/f3.jpg
Enter sub-directory: original/f4/f10/f2/
Original Path: original/f4/f10/f2/f6.jpg
Compressed Path: compressed/f4/f10/f2/f6.jpg
$ tree compressed/
compressed/
├── f1
│   ├── f16
│   │   └── f12.jpg
│   └── f5
│   └── t4.jpg
├── f2
├── f3
├── f4
│   └── f10
│   ├── f2
│   │   └── f6.jpg
│   └── f3.jpg
└── t1.jpg
8 directories, 5 files