Python script to resize and encode images for use with the Station Logo service on HD Radio broadcasts

hdradio_logo_correction.py

#!/usr/bin/env python3

# Requires Python 3.6+ with PIL

# hdradio_logo_correction.py: Utility to resize and encode images 
# for use with the Station Logo service on HD Radio broadcasts
# Copyright (C) 2023-2024 W. Andrew Kirkman <drew@broadcastblueprint.com>
# 
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# 
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.


usage_message = '''\
Usage:
    hdradio_logo_correction.py --callsign XXXX --channel 1 --logo logo_filename.jpg [--output_dir /path/to/output]
Args:
    --callsign XXXX
      [Required] Station call sign, without -FM or -AM suffix if there is one
    --channel 1
      [Required] HD Radio channel ID, number only (e.g. 3 for HD3)
    --logo logo_filename.jpg
      [Required] Path to logo filename to process
    --output_dir /path/to/output
      [Optional] Destination folder of finished logo image, defaults to current working directory'''

import PIL.Image
import sys, os

# Important variables
script_path = sys.path[0]
cwd = os.getcwd()

# Load arguments list
args = sys.argv[1:]

# Arguments list should have an even number of elements
if len(args) % 2 != 0:
  sys.exit(f'Error: Check arguments - odd number of elements given\n\n{usage_message}')

# Make sure all required flags are present
if not set(['--callsign', '--channel', '--logo']).issubset(set(args)):
  sys.exit(f'Error: Not all required arguments present\n\n{usage_message}')

# Find call sign and load it
if '--callsign' in args:
  station_call = args[args.index('--callsign') + 1]
  print(f'Station call sign is {station_call}')
else:
  # Call sign was not given
  sys.exit(f'Error: Missing required argument --callsign\n\n{usage_message}')
  
# Find channel number and load it
if '--channel' in args:
  channel_number = args[args.index('--channel') + 1]
  # Make sure number fits HD1 through HD8
  if not 1 <= int(channel_number) <= 8:
    sys.exit(f'Channel ID {channel_number} out of range (expected 1 through 8)\n\n{usage_message}')
  else:
    print(f'Channel ID is HD{channel_number}')
else:
  # Channel ID was not given
  sys.exit(f'Missing required argument --channel\n\n{usage_message}')
  
# Find logo argument
if '--logo' in args:
  logo_filename = os.path.realpath(args[args.index('--logo') + 1])
  # Check if file exists
  if not os.path.exists(logo_filename):
    sys.exit(f'Error: file {logo_filename} does not exist\n\n{usage_message}')
  else:
    print(f'Found file {logo_filename}')
    f = open(logo_filename, 'rb')
else:
  #Logo filename was not given
  sys.exit(f'Missing required argument --logo\n\n{usage_message}')

# Handle optional --output-dir argument
if '--output_dir' in args:
  output_dir = os.path.realpath(args[args.index('--output_dir') + 1])
  # Check if path exists and is a directory
  if os.path.exists(output_dir):
    if not os.path.isdir(output_dir):
      # Default to current working directory
      print(f'Warning: output destination {output_dir} is not a directory, defaulting to CWD')
      output_dir = cwd
  else:
    # Destination directory doesn't exist
    print(f'Warning: output destination {output_dir} does not exist, defaulting to CWD')
    output_dir = cwd
else:
  # Use default
  print(f'Saving finished image to current directory')
  output_dir = cwd

# Process image
ip = PIL.Image.open(f)
ip = ip.convert('RGB')

# Resize image to 200x200
ip = ip.resize((200,200))

final_filename = f'{output_dir}/SL{station_call}$$0{channel_number}0001.jpg'
out = open(final_filename, 'wb')
ip.save(out, 'jpeg', progressive=False, subsampling=2, quality=75)

print(f'Finished! Processed image available at {final_filename}')