How can I add features from different images and merge them into a final image

Question

I have some images, each of which may contain one or more blobs, I know how to load the image and convert it to binary but I want to be able to add all found blobs from any amount of images and paste them into a final image (which will start out blank).

I don't know if opencv or pillow is better for this as I have very little experience or knowledge in feature extraction.

Code

import cv2

# use cv2 imread method to load image
img1 = cv2.imread("im1.jpg")
img2 = cv2.imread("im2.jpg")

# make bw image
im1_gray = cv2.imread("im1.jpg", cv2.IMREAD_GRAYSCALE)
im2_gray = cv2.imread("im2.jpg", cv2.IMREAD_GRAYSCALE)

# get threshold and binary image
(thresh, im_bw1) = cv2.threshold(im1_gray, 128, 255,
                                 cv2.THRESH_BINARY | cv2.THRESH_OTSU)

# save binary image 1
im_out1 = "bw_image_1"
ext = ".png"
im_name = im_out1 + "_" + str(thresh) + ext
cv2.imwrite(im_name, im_bw1)

# get threshold and binary image
(thresh, im_bw2) = cv2.threshold(im1_gray, 128, 255,
                                 cv2.THRESH_BINARY | cv2.THRESH_OTSU)

# save binary image 2
im_out2 = "bw_image_2"
ext = ".png"
im_name = im_out2 + "_" + str(thresh) + ext
cv2.imwrite(im_name, im_bw2)

Images

Desired output

I don't know how to do this manually, but the output for this would be either a white or grey background with two black blobs in it.

If either of these images had two blobs in it and the other image had three blobs the output image would have five blobs, with positions equal to that of their position in the original image(s), it does not matter if they overlap.

Answer 1

This has been asked before on opencv c++, there should be the same function on python3, hconcat, placing two images side by side, opencv 2.3, c++