Creating a montage of pictures in python

Question

I have no experience with python, but the owner of this script is not responding.

When I drag my photos over this script, to create a montage, it ends up cutting off half of the last photo on the right side edge.

Being 4 pictures wide,

1   2   3   4

5   6   7   8

Pictures 4 and 8 usually get halved. The space is there for the pictures (its blank though)

I was wondering what would be causing this.

I have thought it is possible that it was cropping, but its almost like the half of the picture isn't imported or detected.

Well, you drag selected photos over the script , it outputs something like this

So you can take a bunch of photos or screenshots, and combine them into one single file, easily instead of adding each photo individually.

Size of each photo is roughly 500x250 at max.

EDIT: Here is the upload of the preview, as you can see the images have the slots, but they are "disappearing" if that makes sense.

EDIT2: This script has worked at one time, I haven't edited it or anything. It had worked on a ~70 screenshot montage. No errors or anything. Is there something that my computer could be doing to disrupt the importing of the images?

#!/usr/bin/env python
import os
import sys
from time import strftime
import Image
import ImageDraw
import ImageFont

# parameters
row_size = 4
margin = 3

def generate_montage(filenames):
    images = [Image.open(filename) for filename in filenames]

    width = 0
    height = 0
    i = 0
    sum_x = max_y = 0 
    width = max(image.size[1]+margin for image in images)*row_size
    height = sum(image.size[0]+margin for image in images)

    montage = Image.new(mode='RGBA', size=(width, height), color=(0,0,0,0))
    try:
        image_font = ImageFont.truetype('font/Helvetica.ttf', 18)
    except:
        try:
            image_font = ImageFont.load('font/Helvetica-18.pil')
        except:
            image_font = ImageFont.load_default()
    draw = ImageDraw.Draw(montage)
    offset_x = offset_y = 0

    i = 0
    max_y = 0
    max_x = 0
    offset_x = 0
    for image in images:
        montage.paste(image, (offset_x, offset_y))

        text_coords = offset_x + image.size[0] - 45, offset_y + 120
        draw.text(text_coords, '#{0}'.format(i+1), font=image_font)

        max_x = max(max_x, offset_x+image.size[0])
        if i % row_size == row_size-1: 
            offset_y += max_y+margin
            max_y = 0
            offset_x = 0
        else:
            offset_x += image.size[0]+margin
            max_y = max(max_y, image.size[1])

        i += 1

    if i % row_size:
        offset_y += max_y

    filename = strftime("Montage %Y-%m-%d at %H.%M.%S.png")
    montage = montage.crop((0, 0, max_x, offset_y))
    montage.save(filename)

if __name__ == '__main__':
    old_cwd = os.getcwd()

    os.chdir(os.path.dirname(sys.argv[0]))
    try:
        if len(sys.argv) > 1:
            generate_montage(sys.argv[1:])
    finally:
        os.chdir(old_cwd)

Answer 1

In the size calculation, you use image.size[1] for the width, but that's the height! Use image.size[0] for the width and image.size[1] for the height instead.

Also, a couple of minor stylistic notes:

• Do you really need the script to always run from the program's directory? In any case, os.chdir(os.path.dirname(sys.argv[0])) prevents the program from being executed as ./montage.py, so you may want to use a abspath to allow the invocation from the current directory.

• Instead of having to update the counter i, you can change the for loop to

  for i,image in enumerate(images):
  

• The following lines have no effect, since the variables are overwritten / never used:

  width = 0
  height = 0
  i = 0
  sum_x = max_y = 0 
  

All in all, the code could look like this:

#!/usr/bin/env python
import os.path
import sys
from time import strftime
import Image

row_size = 4
margin = 3

def generate_montage(filenames, output_fn):
    images = [Image.open(filename) for filename in filenames]

    width = max(image.size[0] + margin for image in images)*row_size
    height = sum(image.size[1] + margin for image in images)
    montage = Image.new(mode='RGBA', size=(width, height), color=(0,0,0,0))

    max_x = 0
    max_y = 0
    offset_x = 0
    offset_y = 0
    for i,image in enumerate(images):
        montage.paste(image, (offset_x, offset_y))

        max_x = max(max_x, offset_x + image.size[0])
        max_y = max(max_y, offset_y + image.size[1])

        if i % row_size == row_size-1:
            offset_y = max_y + margin
            offset_x = 0
        else:
            offset_x += margin + image.size[0]

    montage = montage.crop((0, 0, max_x, max_y))
    montage.save(output_fn)

if __name__ == '__main__':
    basename = strftime("Montage %Y-%m-%d at %H.%M.%S.png")
    exedir = os.path.dirname(os.path.abspath(sys.argv[0]))
    filename = os.path.join(exedir, basename)
    generate_montage(sys.argv[1:], filename)