Bash: Batch Resize Images - bash

Question

I'm working on a Bash script that will take an array of directories, iterate through it, create a directory named "processed" inside each directory, and run a command on each file within the directory. Here's my code (read the comment in the code to see what I'm stuck on). Any ideas?
#!/bin/bash
command -v convert >/dev/null 2>&1 || {
echo >&2 "Convert is not installed. Aborting.";
exit 1;
}
declare -a directories_to_process=(
"$HOME/Desktop/Album 1"
"$HOME/Desktop/Album 2"
"$HOME/Desktop/Album 3"
);
for directory in "${directories_to_process[#]}"
do
if [ -d "$directory" ]; then
if [ ! -d "$directory/processed" ]; then
mkdir "$directory/processed"
fi
# Insert code to run the following command on each file in $directory:
#
# convert $directory/$filename -resize 108x108^ -gravity center -extent 108x108 $directory/processed/$filename
fi
done
UPDATE:
Here is the working script:
#!/bin/bash
command -v convert >/dev/null 2>&1 || {
echo >&2 "Convert is not installed. Aborting.";
exit 1;
}
directories_to_process=(
"$HOME/Desktop/Album 1"
"$HOME/Desktop/Album 2"
"$HOME/Desktop/Album 3"
);
for directory in "${directories_to_process[#]}"
do
[[ -d $directory ]] || continue
mkdir -p "$directory/processed"
for infile in "$directory"/*.jpg
do
outfile="$directory/processed/${infile##*/}"
convert "$infile" \
-resize '108x108^' \
-gravity center \
-extent 108x108 \
"$outfile"
done
done

Answer 1

Add this in the commented-out area:
for infile in "$directory"/*; do
outfile="$directory/processed/${infile##*/}"
convert "$infile" \
-resize '108x108^' \
-gravity center \
-extent 108x108 \
"$outfile"
done
A few other notes:
Instead of nesting a great deal of logic inside of if [ -d "$directory" ], consider putting [[ -d $directory ]] || continue at the top of the loop to reduce the nesting depth. (Unlike [ ], quoting is not needed inside [[ ]] in this case).
Instead of testing [ ! -d "$directory/processed" ] and using that to decide whether to create the directory, consider unconditionally running mkdir -p "$directory/processed", which will simply exit with a successful status if the directory already exists.
Consider replacing command -v convert with type convert, which is somewhat better known than the command -v syntax but will have the same effect.
You don't need the declare -a when declaring an array variable outside of a function; simply directories_to_process=( ... ) will work.