sd-rezize-1m.py

from PIL import Image
import os
import math

def resize_and_pad(image_path, output_dir, target_area=1048576, divisor=32):
    # Ensure the output directory exists
    os.makedirs(output_dir, exist_ok=True)

    # Load the image
    img = Image.open(image_path)
    original_width, original_height = img.size
    original_area = original_width * original_height

    # Calculate the resize ratio to reach the target area, while keeping aspect ratio
    resize_ratio = math.sqrt(target_area / original_area)
    new_width = round(original_width * resize_ratio)
    new_height = round(original_height * resize_ratio)

    # Adjust width and height to be divisible by the divisor (32 in this case)
    new_width += (divisor - new_width % divisor) % divisor
    new_height += (divisor - new_height % divisor) % divisor

    # Ensure the final area does not exceed the target area significantly by reducing dimensions if necessary
    while new_width * new_height > target_area:
        new_width -= divisor
        new_height -= divisor

    # Resize the image
    resized_image = img.resize((new_width, new_height), Image.LANCZOS)

    # Finally, create an output image with the adjusted size and pad it if necessary
    output_img = Image.new("RGB", (new_width, new_height), (0, 0, 0))
    output_img.paste(resized_image, (0, 0))

    # Save the processed image
    filename = os.path.splitext(os.path.basename(image_path))[0] + '.jpeg'
    output_path = os.path.join(output_dir, filename)
    output_img.save(output_path, 'JPEG', optimize=True, quality=95)

# Example usage
# Assuming we have a directory 'input_images' with images to be processed
input_dir = 'input_images'
output_dir = 'output'

allowed_extensions = ('.png', '.jpg', '.jpeg')

for image_name in os.listdir(input_dir):
    image_path = os.path.join(input_dir, image_name)
    if os.path.isfile(image_path) and image_name.lower().endswith(allowed_extensions):
        resize_and_pad(image_path, output_dir)