Automatic wallpaper rotator

Automatic desktop wallpaper rotator from specific picture path(s) for LXDE.

script looks for defined image file extensions from multiple directories and sub-directories.

#!/usr/bin/env bash

shopt -s extglob nullglob globstar

# Set the directories to pick images from, separated by spaces
dirs=(
  /path/to/images/1
  /path/to/images/2
  /path/to/images/3
)

# Set the image file extensions to look for
extensions=("jpg" "jpeg" "png" "bmp")

# Set the minimum resolution limit (HEIGHT in pixels)
# Set to -1 to disable.
min_resolution="1050"

# Set the time to change the wallpaper (in seconds)
time_interval="600"

# Set wallpaper mode
# LXDE PCManFM wallpaper modes:
# 1. stretch: Stretch to fill the entire monitor area
# 2. fit: Stretch to fit the monitor area
# 3. center: Center unscaled image on the monitor
# 4. tile: Tile the image to fill the entire monitor area
# 5. crop: Stretch and crop to fill the monitor area
# 6. screen: Stretch to fill complete screen
wallpaper_mode="fit"

# Define the path to the file containing the eligible images
eligible_images_file="$HOME/.local/bin/wallpaper-eligible-images.txt"

# Define log file path
log_file="$HOME/.local/bin/wallpaper-rotator.log"

# Define parser log file path
parser_log_file="$HOME/.local/bin/wallpaper-image-parser.log"

# Check if the file exists and load it if it does
if [[ -f "$eligible_images_file" ]]; then
  echo "Loading eligible images from file: $eligible_images_file"
  readarray -t images < "$eligible_images_file"
else
  # Get the list of images with the specified extensions in the specified directories (including subdirectories)
  images=()
  for dir in "${dirs[@]}"; do
    for ext in "${extensions[@]}"; do
      # Use 'identify' command from ImageMagick to get the resolution of the image
      for image in "$dir"/**/*."$ext"; do
        if [[ $min_resolution == -1 ]]; then
          images+=("$image")
        else
          resolution=$(identify -format '%wx%h' "$image")
          width=$(echo "$resolution" | cut -d 'x' -f 1)
          height=$(echo "$resolution" | cut -d 'x' -f 2)
          if (( height >= min_resolution )); then
            echo "[$(date +'%Y-%m-%d %r UTC %Z')]" "Image $image has resolution of ${width}x${height} pixels, meets the minimum height required ($min_resolution pixels), adding to the list!" | tee -a $parser_log_file
            images+=("$image")
          else
            echo "[$(date +'%Y-%m-%d %r UTC %Z')]" "Image $image has resolution of ${width}x${height} pixels, does not meet the minimum height required ($min_resolution pixels), skipping..." | tee -a $parser_log_file
          fi
        fi
      done
    done
  done

  # Save the eligible images to file
  echo "Saving eligible images to file: $eligible_images_file"
  printf '%s\n' "${images[@]}" > "$eligible_images_file"
fi

while timeout 1 xwininfo -root -size >/dev/null 2>&1; do
  # Count the number of images
  n=${#images[@]}

  # Select a random image and loop
  if (( n > 0 )); then
    rand=$(( RANDOM % n ))
    wallpaper=${images[rand]}
    
    # Get the aspect ratio of the selected image by using 'identify' command from ImageMagick
    image_aspect=$(identify -format "%[fx:w/h]" "$wallpaper")

    # Print the total image count and selected wallpaper with date and time
    printf '[%s] [Total image count: %d] Using image as wallpaper: %s [Resolution: %s, Aspect Ratio: %s, Wallpaper Mode: %s]\n' "$(date +'%Y-%m-%d %r UTC %Z')" "$n" "$wallpaper" "$(identify -format '%wx%h' "$wallpaper")" "$image_aspect" "$wallpaper_mode" | tee -a $log_file

    # Set the wallpaper
    pcmanfm --set-wallpaper="$wallpaper" --wallpaper-mode="$wallpaper_mode"
  fi

  # Wait before changing the wallpaper again
  sleep $time_interval
done

copy wallpaper-rotator.sh and services.sh anywhere you wish (by default paths inside .service file set to ~/.local/bin/) make dirs "systemd" and "user" as ~/.config/systemd/user then copy wallpaper-rotator.service file in there.

then make both .sh scripts executable with chmod +x wallpaper-rotator.sh and chmod +x services.sh then add @/home/$user/.local/bin/services.sh in /home/$user/.config/lxsession/LXDE/autostart to autostart the script.

run systemctl --user start/stop/restart/status wallpaper-rotator.service to start/stop/restart and check status of the service.

* script requires "ImageMagick" to be installed to get correct resolution and aspect ratio information of the wallpaper images. so make sure you have it installed or you can install by "sudo apt install imagemagick"

Github link: https://github.com/minimumattic/wallpaper-rotator