Merging a transparent image to another background

Question

I have 2 images as below, both are in RGBA format

I want to overlay the object into a fixed region in the background. However, my codes produces a weird result:

Can someone have a look at my code to see where I was wrong. Thanks in advance

import numpy as np
import matplotlib.pyplot as plt
import cv2
import glob
from PIL import Image
bg = np.array(Image.open('background.png'))
obj = np.array(Image.open('object.png'))

#RESIZE BACKGROUND
scale_percent = 50 # percent of original size
width = int(bg.shape[1] * scale_percent / 100)
height = int(bg.shape[0] * scale_percent / 100)
dim = (width, height)
bg = resized = cv2.resize(bg, dim, interpolation = cv2.INTER_AREA)

#RESIZE OBJECT
scale_percent = 80 # percent of original size
width = int(obj.shape[1] * scale_percent / 100)
height = int(obj.shape[0] * scale_percent / 100)
dim = (width, height)
# resize image
obj = resized = cv2.resize(obj, dim, interpolation=cv2.INTER_AREA)


#create ROI
rows, cols, channels = obj.shape
bg_rows, bg_cols, bg_channels = bg.shape
roi = bg[bg_rows-rows:bg_rows:, bg_cols-cols:bg_cols:]

img2gray = cv2.cvtColor(obj, cv2.COLOR_BGR2GRAY)
ret, mask = cv2.threshold(img2gray, 220, 255, cv2.THRESH_BINARY_INV)

mask_inv = cv2.bitwise_not(mask)

img1_bg = cv2.bitwise_and(roi, roi, mask=mask_inv)

img2_fg = cv2.bitwise_and(obj, obj, mask=mask)

dst = cv2.add(img1_bg, img2_fg)
bg[bg_rows-rows:bg_rows:, bg_cols-cols:bg_cols:] = dst
Image.fromarray(bg)

Answer 1

You should use ImageDraw() function from the pillow library. It will solve your problem by giving the mode same as the 2nd image.