Convert image with color from first pixel with imagemagick

convert.sh

#/bin/bash

# Unzip all zip files
for f in *.zip; do unzip "$f" -d "${f%.*}"; done 

# Move all jpgs to displate
find . \( -iname "*.jpg" ! -iname "*_hoodie.jpg" \) -mindepth 2 -type f -print -exec mv -f {} ../displate/ \;

cd ../displate

# Fix faulty file names
for f in *\ *; do mv -f "$f" "${f// /_}"; done

# Resize all displate files
for file in *.jpg; do
    echo "converting displate file $file right now"
    W=`identify "$file" | cut -f 3 -d " " | sed s/x.*//` # width
    H=`identify "$file" | cut -f 3 -d " " | sed s/.*x//` # height
    if [ "$W" -gt "$H" ] && [ "$W" != 6300 ]; then
        convert $file -format '%[pixel:p{4,4}]' info:- | xargs -I{} convert $file -resize 6300x4500 -background {} -colorspace sRGB -gravity center -extent 6300x4500 $file
    elif [ "$W" -le "$H" ] && [ "$H" != 6300 ]; then
        convert $file -format '%[pixel:p{4,4}]' info:- | xargs -I{} convert $file -resize 4500x6300 -background {} -colorspace sRGB -gravity center -extent 4500x6300 $file
    fi
done

cd ../zips

# Move all pngs to shirts
find . \( -iname "*.png" ! -iname "*_hoodie.png" \) -mindepth 2 -type f -print -exec cp {} ../shirts/ \;

cd ../shirts

# Fix faulty file names
for f in *\ *; do mv -f "$f" "${f// /_}"; done

cd ../zips

# Copy all pngs from shirts to redbubble
find . \( -iname "*.png" ! -iname "*_hoodie.png" \) -mindepth 2 -type f -print -exec cp {} ../redbubble/ \;

cd ../redbubble

# Resize all pngs in redbubble
for file in *.png; do
    echo "converting redbubble file $file right now"
    W=`identify "$file" | cut -f 3 -d " " | sed s/x.*//` # width
    H=`identify "$file" | cut -f 3 -d " " | sed s/.*x//` # height
    if [ "$W" -gt "$H" ] && [ "$W" != 6300 ]; then
        convert $file -resize 7632x6480 -gravity center $file
    elif [ "$W" -le "$H" ] && [ "$H" != 6300 ]; then
        convert $file -resize 6480x7632 -gravity center $file
    fi
done

cd ../zips

# Remove extracted folders
find . -iname '*.zip' -exec sh -c 'rm -Rf "${1%.*}"' _ {} \;