How to paste an image onto a larger image using Pillow?

Question

I\'ve got a fairly simple code file:

from PIL import Image
til = Image.new(\"RGB\",(50,50))
im = Image.open(\"tile.png\") #25x25
til.paste(im)
til.paste(im,(         


        

Answer 1

So I might be a little late, but maybe it helps the people coming after a little:

When I had the same issue I couldn't find much about it. So I wrote a snippet which pastes one image into another.

def PasteImage(source, target, pos):

    # Usage:
    # tgtimg = PIL.Image.open('my_target_image.png')
    # srcimg = PIL.Image.open('my_source_image.jpg')
    # newimg = PasteImage(srcimg, tgtimg, (5, 5))
    # newimg.save('some_new_image.png')
    #

    smap = source.load()
    tmap = target.load()
    for i in range(pos[0], pos[0] + source.size[0]): # Width
        for j in range(pos[1], pos[1] + source.size[1]): # Height
            # For the paste position in the image the position from the top-left
            # corner is being used. Therefore 
            # range(pos[x] - pos[x], pos[x] + source.size[x] - pos[x])
            # = range(0, source.size[x]) can be used for navigating the source image.

            sx = i - pos[0]
            sy = j - pos[1]

            # Change color of the pixels
            tmap[i, j] = smap[sx, sy]

    return target

Not necessarely the best approach, since it takes roughly O(N^2), but it works for small images. Maybe someone can improve the code to be more efficient.

I made it in a hurry, so it doesnt have input validation either. just know that the width and height of the source image MUST be smaller or equal to width and height of the target image, otherwise it will crash. You can also only paste the whole image, and not sections or non-rectangular images.