Create a Photo Collage with Python PIL

# Import necessary libraries
import os
from PIL import Image, ImageDraw

# Define folder that has images
directory = "./images"

# Get list of images
images = [i for i in os.listdir(directory) if i.endswith(".jpg") or i.endswith(".jpeg") or i.endswith(".png")]

# Define the size of output collage and the size of 1 image in the collage as (width, height) tuple
# Below values will determine how many images will be put horizontally vs. vertically
# E.g. in below case -  3600/600 = 6  and 1600/4 = 4 - The collage will be 6x4
expected_size_collage = (3600, 1600)
expected_size_image = (600, 400)

# Create collage canvas to paste the images
collage = Image.new("RGBA", expected_size_collage, color=(255,255,255,255))

# Loop through image files
file_count = 0
for h in range(0, expected_size_collage[1], expected_size_image[1]):
    for w in range(0, expected_size_collage[0], expected_size_image[0]):
        # Read image
        file_name = images[file_count]
        path = directory + "/" + file_name
        image = Image.open(path).convert("RGBA")

        # Get the original image width and height
        image_width = image.size[0]
        image_height = image.size[1]

        # Get how the width and height should be
        width_factor = image_width / expected_size_image[0]
        height_factor = image_height / expected_size_image[1]

        # If width and height factors are same, no cropping is needed
        # If not, we need to crop image to the same ratio as expected_size_image
        if width_factor != height_factor:
            # Get the limiting factor
            factor = min(width_factor, height_factor)

            # Calculate the resulting image width and height
            expected_width = round(factor * expected_size_image[0])
            expected_height = round(factor * expected_size_image[1])

            # Get minx, miny, maxx, and maxy coordinates of new image
            start_width = round((image_width - expected_width) / 2)
            start_height = round((image_height - expected_height) / 2)
            end_width = expected_width + round((image_width - expected_width) / 2)
            end_height = expected_height + round((image_height - expected_height) / 2)

            # Crop the image
            image = image.crop((start_width, start_height, end_width, end_height))

        # Once the image is cropped, resize the image
        # Image should have the aspect ratio as the expected_size_image so resize won't disturb the image
        image = image.resize(expected_size_image)

        # Copy image to collage canvas
        collage.paste(image, (w, h))
        file_count += 1

# Save collage
collage.save("collage.png") 

# Import necessary libraries
import os
from PIL import Image, ImageDraw

# Define folder that has images
directory = "./images"

# Get list of images
images = [i for i in os.listdir(directory) if i.endswith(".jpg") or i.endswith(".jpeg") or i.endswith(".png")]

# Define the size of output collage and the size of 1 image in the collage as (width, height) tuple
# Below values will determine how many images will be put horizontally vs. vertically
# E.g. in below case -  3600/600 = 6  and 1600/4 = 4 - The collage will be 6x4
expected_size_collage = (3600, 1600)
expected_size_image = (600, 400)

# Create collage canvas to paste the images
collage = Image.new("RGBA", expected_size_collage, color=(255,255,255,255))

# Loop through image files
file_count = 0
for h in range(0, expected_size_collage[1], expected_size_image[1]):
    for w in range(0, expected_size_collage[0], expected_size_image[0]):
        # Read image
        file_name = images[file_count]
        path = directory + "/" + file_name
        image = Image.open(path).convert("RGBA")

        # Get the original image width and height
        image_width = image.size[0]
        image_height = image.size[1]

        # Get how the width and height should be
        width_factor = image_width / expected_size_image[0]
        height_factor = image_height / expected_size_image[1]

        # If width and height factors are same, no cropping is needed
        # If not, we need to crop image to the same ratio as expected_size_image
        if width_factor != height_factor:
            # Get the limiting factor
            factor = min(width_factor, height_factor)

            # Calculate the resulting image width and height
            expected_width = round(factor * expected_size_image[0])
            expected_height = round(factor * expected_size_image[1])

            # Get minx, miny, maxx, and maxy coordinates of new image
            start_width = round((image_width - expected_width) / 2)
            start_height = round((image_height - expected_height) / 2)
            end_width = expected_width + round((image_width - expected_width) / 2)
            end_height = expected_height + round((image_height - expected_height) / 2)

            # Crop the image
            image = image.crop((start_width, start_height, end_width, end_height))

        # Once the image is cropped, resize the image
        # Image should have the aspect ratio as the expected_size_image so resize won't disturb the image
        image = image.resize(expected_size_image)

        # Copy image to collage canvas
        collage.paste(image, (w, h))
        file_count += 1

# Save collage
collage.save("collage.png")