Multiple Pngs/pdfs Per Page Using Python

I have a set of images I have saved as .png and .pdf. I was wondering if there is anyway to combine either the pngs or pdfs together in such a way I could have multiple per page. I

Solution 1:

You can use PIL/pillow to create big empty image and then put small images on this image in different places.

from PIL import Image

# get images    
img1 = Image.open('image1.png')
img2 = Image.open('image2.png')
img3 = Image.open('image3.png')
img4 = Image.open('image4.png')

# get width and height
w1, h1 = img1.size
w2, h2 = img2.size
w3, h3 = img3.size
w4, h4 = img4.size

# to calculate size of new image 
w = max(w1, w2, w3, w4)
h = max(h1, h2, h3, h4)

# create big empty image with place for images
new_image = Image.new('RGB', (w*2, h*2))

# put images on new_image
new_image.paste(img1, (0, 0))
new_image.paste(img2, (w, 0))
new_image.paste(img3, (0, h))
new_image.paste(img4, (w, h))

# save it
new_image.save('new.png')

BTW: you could write it in for-loop(s).

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The same with program ImageMagick without Python.

But you can use these commands in Python with os.system('convert ...')

$ convert image1.png image2.png +append row1.png
$ convert image3.png image4.png +append row2.png
$ convert row1.png row2.png -appendnew.png

+append join in row, -append join in column.

It is possible to do it even in one command: Stitching Image Set Together

$ convert image1.png image2.png image3.png image4.png +append -crop 2x1@ -appendnew.png

If you use new.pdf instead of new.png then it can create PDF

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There is Python module Wand which uses ImageMagick. Code is similar to pillow.

from wand.image import Image

img1 = Image(filename='image1.png')
img2 = Image(filename='image2.png')
img3 = Image(filename='image3.png')
img4 = Image(filename='image4.png')

w1, h1 = img1.size
w2, h2 = img2.size
w3, h3 = img3.size
w4, h4 = img4.size

w =max(w1, w2, w3, w4)
h =max(h1, h2, h3, h4)

new_image = Image(width=w*2, height=h*2)

new_image.composite(image=img1, left=0, top=0)
new_image.composite(image=img2, left=w, top=0)
new_image.composite(image=img3, left=0, top=h)
new_image.composite(image=img4, left=w, top=h)

new_image.save(filename='new.png')

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Example with cv2 and numpy but it works when images have the same size. If they have different then they need empty rows and columns to have the same size.

import cv2
import numpy as np

img1 = cv2.imread('image1.png')
img2 = cv2.imread('image2.png')
img3 = cv2.imread('image3.png')
img4 = cv2.imread('image4.png')

row1 = np.concatenate((img1, img2), axis=1)
row2 = np.concatenate((img3, img4), axis=1)
new_image = np.concatenate((row1, row2))

# or
row1 = np.hstack((img1, img2))
row2 = np.hstack((img3, img4))
new_image = np.vstack((row1, row2))

cv2.imwrite('new.png', new_image)

Similar with matplotlib and numpy

import matplotlib.image
import numpy as np

img1 = matplotlib.image.imread('image1.png')
img2 = matplotlib.image.imread('image2.png')
img3 = matplotlib.image.imread('image3.png')
img4 = matplotlib.image.imread('image4.png')

row1 = np.concatenate((img1, img2), axis=1)
row2 = np.concatenate((img3, img4), axis=1)
new_image = np.concatenate((row1, row2))

# or
row1 = np.hstack((img1, img2))
row2 = np.hstack((img3, img4))
new_image = np.vstack((row1, row2))

matplotlib.image.imsave('new.png', new_image)

Similar with imageio and numpy

import imageio
import numpy as np

img1 = imageio.imread('image1.png')
img2 = imageio.imread('image2.png')
img3 = imageio.imread('image3.png')
img4 = imageio.imread('image4.png')

row1 = np.concatenate((img1, img2), axis=1)
row2 = np.concatenate((img3, img4), axis=1)
new_image = np.concatenate((row1, row2))

# or
row1 = np.hstack((img1, img2))
row2 = np.hstack((img3, img4))
new_image = np.vstack((row1, row2))

imageio.imwrite('new.png', new_image)