Foto.py

import os
import math
from PIL import Image

# read imgs and save to one list

def read_imgs(path_dir, img_indexes=None):
    all_img = []
    for filename in os.listdir(path_dir):
        im = Image.open(path_dir+filename)
        all_img.append(im)

    if img_idnexes is not None:
        all_img_ind = []
        for el in img_idnexes:
            all_img_ind.append(all_img[el])
        return all_img_ind

    return all_img


# convert all imgs to square accorging to biggest size
def make_all_square(list_imgs):
    list_imgs_copy = list_imgs
    for i in range(len(list_imgs)):
        width, height = list_imgs[i].size
        if width != height:
            sq_size = max(width, height)
            # create new white image
            new_img = Image.new("RGB", (sq_size, sq_size), (255, 255, 255, 0))
            if width > height:
                new_img.paste(list_imgs_copy[i], (0, (sq_size - height)//2))
            else:
                new_img.paste(list_imgs_copy[i], ((sq_size - width)//2, 0))

            list_imgs_copy[i] = new_img

    return list_imgs_copy


# create A4 empty picture (3508 x 2480) - ~15 pxls frame
def new_A4():
    return Image.new("RGB", (2480 - 15, 3508 - 15), (255, 255, 255))


# calculate the size of the squares according to number of pictures: sqrt(number_of_pictures) - number of img in a row -> width = height
def picture_size(n_pict):
    w_A4 = (2480 - 15)
    im_in_row = math.ceil(math.sqrt(n_pict))  # ceil to get max number
    size = w_A4 // im_in_row
    return round(size)


# resize all pictures to one size (given one)
def resize_all(list_imgs, size):
    list_imgs_copy = list_imgs
    for i in range(len(list_imgs_copy)):
        list_imgs_copy[i] = list_imgs_copy[i].resize((size, size))
    return list_imgs_copy


# place pictures to the empty A4
def combine_all(A4, list_imgs):
    width_p, height_p = list_imgs[0].size
    width_A4, height_A4 = A4.size

    im_row = math.ceil(math.sqrt(len(list_imgs)))
    im_col = math.ceil(len(list_imgs)/im_row)
    k = 0
    # forleft point in range width A4 with step of picture size
    for top in range(0, height_p * im_row, height_p):
        for left in range(0, width_p * im_col, width_p):
            if k >= len(list_imgs):
                break
            A4.paste(list_imgs[k], (left, top))
            k += 1

    return A4


def collage(path_to_folder, path_to_save, ind_list=None):
    img_list = read_imgs(path_to_folder, ind_list)
    sq_imgs = make_all_square(img_list)
    size = picture_size(len(sq_imgs))
    resized_imgs = resize_all(sq_imgs, size)
    result = combine_all(new_A4(), resized_imgs)
    result.save(os.path.join(path_to_save, "result.jpg"))