How to modify patches made by patchify?

I am using patchify library to patch a big image:

img = cv2.imread("resized.jpg")patches_img = patchify(img, (224,224,3), step=224)print(patches_img.shape)

Then I save the patches:

for i in range(patches_img.shape[0]):    for j in range(patches_img.shape[1]):        single_patch_img = patches_img[i, j, 0, :, :, :]        if not cv2.imwrite('patches/images/'+'image_'+'_'+ str(i)+str(j)+'.jpg', single_patch_img):            raise Exception("Could not write the image")

Then, I want to make some modification on any of those patches, e.g. draw bounding boxes, so when I use unpatchify to merge patches together, the bounding boxes would be displayed on the reconstructed image.

After making the modifications, I run the following code to merge the patches back together:

reconstructed_image = unpatchify(patches_img, img.shape)cv2.imwrite("unpatched.jpg", reconstructed_image)

But the reconstructed image generated is the same as the original one, with no change visible.I assume this is because unpatchify reads the variable patches_img, which has still stored the original, unmodified patches.

I tried the following:

patches = 'patches/images/*.jpg'reconstructed_image = unpatchify(patches, img.shape)cv2.imwrite("unpatched.jpg", reconstructed_image)

But I am getting AttributeError: 'str' object has no attribute 'shape'

Thanks you!