How to Merge a Transparent Png Image with Another Image Using Pil

How to merge a transparent png image with another image using PIL

from PIL import Image

background = Image.open("test1.png")
foreground = Image.open("test2.png")

background.paste(foreground, (0, 0), foreground)
background.show()

First parameter to .paste() is the image to paste. Second are coordinates, and the secret sauce is the third parameter. It indicates a mask that will be used to paste the image. If you pass a image with transparency, then the alpha channel is used as mask.

Check the docs.

How to paste a PNG image with transparency to another image in PIL without white pixels?

You need to specify the image as the mask as follows in the paste function:

import os
from PIL import Image

filename = 'pikachu.png'
ironman = Image.open(filename, 'r')
filename1 = 'bg.png'
bg = Image.open(filename1, 'r')
text_img = Image.new('RGBA', (600,320), (0, 0, 0, 0))
text_img.paste(bg, (0,0))
text_img.paste(ironman, (0,0), mask=ironman)
text_img.save("ball.png", format="png")

Giving you:

---

To centre both the background image and the transparent image on the new text_img, you need to calculate the correct offsets based on the images dimensions:

text_img.paste(bg, ((text_img.width - bg.width) // 2, (text_img.height - bg.height) // 2))
text_img.paste(ironman, ((text_img.width - ironman.width) // 2, (text_img.height - ironman.height) // 2), mask=ironman)

PIL - Image Paste On Another Image With Alpha

The closest I got was to use the alpha_composite function found here. Works really rather well!

how to put transparent image to another image using PIL without .paste() class

Here is a simplified version using these two images which are suitably resized and also partially transparent:

#!/usr/bin/env python3

from PIL import Image

# Open pitcher and pitch images
bg = Image.open('pitch.jpg')
fg = Image.open('pitcher.png').convert('RGBA')
w, h = fg.width, fg.height

# Iterate over rows and columns
for y in range(h):
   for x in range(w):
      # Get components of foreground pixel
      r, g, b, a = fg.getpixel((x,y))
      # If foreground is opaque, overwrite background with foreground
      if a>128:
          bg.putpixel((x,y), (r,g,b))

# Save result    
bg.save('result.png')

How to merge a transparent png image with another image using Scikit-image

Inspired by user8190410's answer, I built my own function to do it:

from skimage import data
import numpy as np

x, y = 100, 100
background = data.imread('background.jpg') / 255.
image = data.imread('image.png') / 255.

background_height, background_width, background_depth = background.shape
image_height, image_width, image_depth = image.shape

template = np.zeros((background_height, background_width, image_depth))
template[y : y + image_height, x : x + image_width, :] = image

mask = np.stack([template[:,:,3] for _ in range(3)], axis = 2)
inv_mask = 1. - mask
result = background[:,:,:3] * inv_mask + template[:,:,:3] * mask
plt.figure(figsize = (15, 15))
plt.subplot(1, 3, 2)
plt.imshow(image)
plt.subplot(1, 3, 1)
plt.imshow(background)
plt.subplot(1, 3, 3)
plt.imshow(result)
plt.tight_layout()
plt.show()

Please let me know if I can do something to improve computation speed

Merging perspective corrected image with transparent background template image using PILLOW [PIL, Python]

You don't really need to write any Python, you can just do it in the Terminal with ImageMagick using a "Perspective Transform" like this:

magick cover.png -virtual-pixel none -distort perspective "0,0 96,89 %w,0 325,63 %w,%h 326,522 0,%h 96,491" template.png +swap -flatten result.png

Looking at the parameters to the perspective transform, you can hopefully see there are 4 pairs of coordinates, one pair for each corner of the transform showing how the source location gets mapped in the output image.

So, the top-left corner of the cover (0,0) gets mapped to the top-left of the empty area in the template (96,89). The top right of the cover (width,0) gets mapped to the top-right of the empty area of the template (325,63). The bottom-right of the cover (width,height) gets mapped to the bottom-right of the empty area on the template (326,522). The bottom-left of the cover (0,height) gets mapped to the bottom-left corner of the empty area of the template (96,491).

If you are using the old v6 ImageMagick, replace magick with convert.

---

Note that, if you really want to do it in Python, there is a Python binding called wand here. I am not very experienced with wand but this seems to be equivalent:

#!/usr/bin/env python3

from itertools import chain
from wand.color import Color
from wand.image import Image

with Image(filename='cover.png') as cover, Image(filename='template.png') as template:
    w, h = cover.size
    cover.virtual_pixel = 'transparent'
    source_points = (
        (0, 0),
        (w, 0),
        (w, h),
        (0, h)
    )
    destination_points = (
        (96, 89),
        (325, 63),
        (326, 522),
        (96, 491)
    )
    order = chain.from_iterable(zip(source_points, destination_points))
    arguments = list(chain.from_iterable(order))
    cover.distort('perspective', arguments)

    # Overlay cover onto template and save
    template.composite(cover,left=0,top=0)
    template.save(filename='result.png')

Keywords: Python, ImageMagick, wand, image processing, perspective transform, distort.

---

Related Topics