Collagen erstellen aus Fotos im Ordner

collage.py

import os

import pillow_heif
from PIL import Image, ImageChops

pillow_heif.register_heif_opener()

directory = 'D:\\fotos\\klein'
output_dir = 'D:\\fotos\\collagen'
canvas_size = 5000
os.makedirs(output_dir, exist_ok=True)

aspect_threshold = 1.3

square_images = []
wide_images = []


def rotate_and_trim(img, angle=90, bg_color=(255, 255, 255)):
    # Bild drehen (expand=True verhindert Abschneiden)
    rotated = img.rotate(angle, expand=True)

    # Wenn das Bild Transparenz hat → einfacher Fall
    if 'A' in rotated.getbands():
        bbox = rotated.getbbox()
        return rotated.crop(bbox)

    # Wenn kein Alphakanal → über Hintergrundfarbe Differenz berechnen
    if bg_color is None:
        # Versuchen, Hintergrundfarbe automatisch zu erraten (oben links)
        bg_color = rotated.getpixel((0, 0))

    bg = Image.new(rotated.mode, rotated.size, bg_color)
    diff = ImageChops.difference(rotated, bg)
    bbox = diff.getbbox()
    return rotated.crop(bbox) if bbox else rotated


for filename in sorted(os.listdir(directory)):
    if not filename.lower().endswith((".jpg", ".jpeg", ".png", ".heic")):
        continue
    try:
        path = os.path.join(directory, filename)
        img = Image.open(path)
        w, h = img.size
        if w < h:
            ratio = h / w
        else:
            ratio = w / h

        if ratio > aspect_threshold:
            wide_images.append(path)
        else:
            square_images.append(path)
    except Exception as e:
        print(f'Fehler bei {filename}: {e}')

print("Es wurden " + str(len(wide_images) + len(square_images)) + " Bilder gefunden")


def resize_with_aspect(img, target_w, target_h):
    # Maximale Seite auf target setzen, andere proportional skalieren
    w, h = img.size
    scale_w = target_w / w
    scale_h = target_h / h

    if scale_w < scale_h:
        # Breite anpassen, Höhe proportional kleiner
        new_w = target_w
        new_h = int(h * scale_w)
    else:
        # Höhe anpassen, Breite proportional kleiner
        new_w = int(w * scale_h)
        new_h = target_h

    resized_img = img.resize((new_w, new_h), Image.LANCZOS)

    # Weißes Bild erstellen mit Zieldimensionen
    background = Image.new('RGB', (target_w, target_h), (255, 255, 255))
    offset = ((target_w - new_w) // 2, (target_h - new_h) // 2)
    background.paste(resized_img, offset)
    return background


def create_collage(layout, index):
    collage = Image.new('RGB', (canvas_size, canvas_size), (255, 255, 255))

    for item in layout:
        img = Image.open(item['path'])
        w, h = img.size
        if w < h:
            img = rotate_and_trim(img)
        img = resize_with_aspect(img, item['w'], item['h'])
        collage.paste(img, (item['x'], item['y']))

    collage.save(os.path.join(output_dir, f'collage_{index:03}.jpg'))


collage_index = 1
while square_images or wide_images:
    layout = []

    if len(wide_images) >= 2:
        slot_h = canvas_size // 2
        for y in range(2):
            path = wide_images.pop(0)
            layout.append({'path': path, 'x': 0, 'y': y * slot_h, 'w': canvas_size, 'h': slot_h})
        create_collage(layout, collage_index)

    elif len(wide_images) >= 1 and len(square_images) >= 2:
        wide_path = wide_images.pop(0)
        layout.append({'path': wide_path, 'x': 0, 'y': 0, 'w': canvas_size, 'h': canvas_size // 2})
        w_sq = canvas_size // 2
        h_sq = canvas_size // 2
        for i in range(2):
            sq = square_images.pop(0)
            layout.append({'path': sq, 'x': i * w_sq, 'y': canvas_size // 2, 'w': w_sq, 'h': h_sq})
        create_collage(layout, collage_index)

    elif len(square_images) >= 4:
        w_sq = canvas_size // 2
        h_sq = canvas_size // 2
        for i in range(4):
            path = square_images.pop(0)
            layout.append({'path': path, 'x': (i % 2) * w_sq, 'y': (i // 2) * h_sq, 'w': w_sq, 'h': h_sq})
        create_collage(layout, collage_index)

    else:
        rest = square_images + wide_images
        w_sq = canvas_size // 2
        h_sq = canvas_size // 2
        for i, p in enumerate(rest[:4]):
            layout.append({'path': p, 'x': (i % 2) * w_sq, 'y': (i // 2) * h_sq, 'w': w_sq, 'h': h_sq})
        create_collage(layout, collage_index)
        break

    collage_index += 1

print(f'Erstellt {collage_index - 1} Collagen im Ordner {output_dir}')