Mat2 wrapper for recursive image metadata cleaning

A shell alias and script for recursively stripping metadata from image files with mat2.

What is metadata?

Please read the article I wrote about metadata to get an idea about metadata and why it matters to remove it.

The problem

mat2 is an excellent program that removes metadata from files. But the problem I encountered while using it is that it sometimes breaks when it encounters file types such as .xml. So it makes recursive metadata removing problematic.

Solutions

There are two ways to do this.

Alias

You can add a simple shell alias to your .bashrc or .zshrc to filter out all the .png, .jpg, .jpeg and .gif files from the rest allowing mat2 to only remove data from that files specifically.

Showing metadata

find . -type f \( -iname "*.jpg" -o -iname "*.jpeg" -o -iname "*.png" -o -iname "*.gif" \) -print0 | while IFS= read -r -d "" f; do mat2 -s "$f"; done

Removing metadata

find . -type f \( -iname "*.jpg" -o -iname "*.jpeg" -o -iname "*.png" -o -iname "*.gif" \) -print0 | while IFS= read -r -d "" f; do mat2 --inplace "$f"; done

Shell Script

This is the way I like to do it. Because it allows me to run the script from else where instead of cd in to the directory i want to remove metadata of.

#!/usr/bin/env bash

TARGET_DIR="$1"
OPTION="$2"

show_data() {
    find "$TARGET_DIR" -type f \( -iname "*.jpg" -o -iname "*.jpeg" -o -iname "*.png" -o -iname "*.gif" \) -print0 | while IFS= read -r -d '' file; do
        printf "\nShowing metadata of image %s\n" "$file"
        mat2 -s "$file"
    done
}

remove_data() {
    find "$TARGET_DIR" -type f \( -iname "*.jpg" -o -iname "*.jpeg" -o -iname "*.png" -o -iname "*.gif" \) -print0 | while IFS= read -r -d '' file; do
        printf "\nDeleting Metadata of image %s\n" "$file"
        mat2 --inplace "$file"
    done
}

if [ -z "${1:-}" ]; then
    printf "\nError: No target directory was provided\n"
    printf "\nPlease provide a target directory with cleaner target-directory\n"
    exit 1
fi

if [ ! -d "$TARGET_DIR" ]; then
    printf "\nThe directory %s is not found" "$TARGET_DIR"
    exit 1
fi

case "${2:-}" in
-c)
    remove_data
    ;;
-s)
    show_data
    ;;
"")
    printf "\nNo argument provided please provide an argument (-s or -c)\n"
    exit 1
    ;;
*)
    printf "\ninvalid option provided exiting the script\n"
    exit 1
    ;;
esac

The script is pretty self explanatory with safety checks for checking whether directory already exists and null target or null option checks. The mat2 command efficiently removes all the metadata in the target directory.

Usage

Remove metadata

./cleaner.sh <target-dir> -c

Check/show metadata

./cleaner.sh <target-dir> -s

What to use

In my opinion using the shell script is much more safe because it has the safety controls such as checking whether directory already exists or not. But if you don’t care about the safety options or just don’t want a shell script, please add the aliases to your .bashrc or .zshrc to use it.