Complete rewrite of batch_resizer.py script

Author: D10f

batch_resizer/main.py

@@ -0,0 +1,178 @@
+#!/usr/bin/python3
+
+""""
+Resize and transform images into different image file formats.
+"""
+
+from PIL import Image
+from concurrent.futures import ThreadPoolExecutor
+import argparse
+import logging
+import pathlib
+import sys
+import re
+
+CURRENT_VERSION = '1.0.0'
+VALID_FORMATS = ['.jpg', '.jpeg', '.png', '.webp']
+ALPHA_CHANNEL_UNSUPPORTED = ['.jpg', '.jpeg']
+FILE_NOT_FOUND_ERR_CODE = 130
+
+# TODO: Validate files based on mime type rather than file extension
+# TODO: Verbosity and console output with logging
+# TODO: Implement design patterns (strategy?) for additional options per extension
+
+def main():
+    args = parse_arguments()
+    print(args.usage)
+    return
+
+    if args.verbose:
+        pass
+
+    if not args.output.exists():
+        create_dir(args.output, parents=args.parents)
+
+    image_files = select_images(args.input)
+
+    if not image_files:
+        print('No files found, exiting...')
+        sys.exit(FILE_NOT_FOUND_ERR_CODE)
+
+    with ThreadPoolExecutor() as executor:
+        for img in image_files:
+                executor.submit(
+                    process_image,
+                    img,
+                    formats=args.formats,
+                    width=args.width,
+                    height=args.height,
+                    dest=args.output
+                )
+
+
+def select_images(files):
+    '''Selects all the valid image files'''
+    return [f for f in files if is_valid_format(f)]
+
+
+def is_valid_format(file):
+    '''Verifies input to be a file, and with a valid extension'''
+    return file.is_file() and file.suffix.lower() in VALID_FORMATS
+
+
+def create_dir(target_dir, parents=False):
+    '''
+    Creates a directory on input location. Parents option set to True will
+    create any missing directories.
+    '''
+
+    try:
+        target_dir.mkdir(parents=parents)
+    except FileNotFoundError:
+        print('Could not find missing directories, try running with -p flag.')
+        sys.exit(FILE_NOT_FOUND_ERR_CODE)
+
+
+def get_filepath(filename, output_dir, matches=0):
+    '''
+    Returns a path-like object of the input filename. Verifies if that filename
+    already exists in output directory, and appends a suffix to avoid accidental
+    data loss.
+    '''
+    
+    result = pathlib.Path(output_dir, filename)
+
+    if result in output_dir.iterdir():
+        name, ext = filename.split('.')
+
+        if matches == 0:
+            name += '_copy1'
+
+        filename = name.replace(f'_copy{matches - 1}', f'_copy{matches}') + f'.{ext}'
+        result = get_filepath(filename, output_dir, matches=matches+1)
+
+    return result
+
+
+def process_image(img_path, formats=None, width=None, height=None, dest=None):
+    '''Converts the image format and/or resizes, preserving aspect ratio.'''
+
+    output_formats = formats or [img_path.suffix.lower()]
+
+    with Image.open(img_path) as img:
+        # determine output dimensions
+        w = width or img.width
+        h = height or img.height
+
+        # resize image object (preserving aspect-ratio)
+        img.thumbnail((w, h))
+
+        # Output one file per format
+        for f in output_formats:
+            filename = img_path.stem
+
+            # If img was resized, append new dimensions to output filename
+            if width or height:
+                filename += f'_{img.width}-{img.height}'
+
+            filename += f.lower()
+
+            # avoid overwrite by checking for duplicate filenames
+            output_file = get_filepath(filename, dest)
+
+            # Remove alpha channel when converting to formats that don't support it
+            if f in ALPHA_CHANNEL_UNSUPPORTED:
+                img = img.convert('RGB')
+
+            # save image
+            print(output_file)
+            img.save(output_file)
+
+
+def parse_arguments():
+    parser = argparse.ArgumentParser(add_help=False)
+    parser.add_argument('input',
+        help='Path to the image file(s) to process',
+        nargs='+',
+        type=pathlib.Path
+    )
+    parser.add_argument('-o', '--output-dir',
+        help="Directory to save processed images. Create dir it if doesn't exist.",
+        default=pathlib.os.getcwd(),
+        type=pathlib.Path,
+        dest='output'
+    )
+    parser.add_argument('-p', '--create-parents',
+        help="Creates missing directories for target output",
+        action='store_true',
+        dest='parents'
+    )
+    parser.add_argument('-w', '--width',
+        help='Pixel width of the output image',
+        type=int,
+        metavar='width'
+    )
+    parser.add_argument('-h', '--height',
+        help='Pixel height of the output image',
+        type=int,
+        metavar='height'
+    )
+    parser.add_argument('-f', '--formats',
+        help='Transform images to the specified format(s)',
+        nargs='+',
+        choices=['.jpg', '.jpeg', '.png', '.webp']
+    )
+    parser.add_argument('-v', '--verbose',
+        help='Produces additional output as the program runs',
+        action='count',
+        default=0
+    )
+    parser.add_argument('--version',
+        action='version',
+        version=f'%(prog)s v{CURRENT_VERSION}'
+    )
+    return parser.parse_args()
+
+
+if __name__ == '__main__':
+    sys.exit(main())

batch_resizer/requirements.txt

@@ -0,0 +1 @@
+Pillow == 8.4