Watermarking Image using Pillow

Question

I'am trying to watermark an image however iam not able to do so without pasting the watermark with its background color. (see below example)

I tried to implement the tutorial from the following website .

As can be seen from below images, the Current outcome shows watermark with its black background which is not desirable. (See expected outcome image for required result)

I'am using Linux/Ubuntu 20.04 with Python 3.8

Here is the content:

Background Image :

Watermark Image :

Current Outcome :

Expected Outcome :

Current Outcome after making watermark transparent :

Below is code i have used which is same as website tutorial example.

#adding transparency to watermark image(as suggested)
from PIL import Image, ImageFilter
img = Image.open('path_to_watermark').convert('RGBA')
img.putalpha(130) 
img.save('path_to_watermark')


def watermark_with_transparency(input_image_path, output_image_path, watermark_image_path, position):
    base_image = Image.open(input_image_path).convert('RGBA')
    watermark = Image.open(watermark_image_path).convert('RGBA')
    width, height = base_image.size
    transparent = Image.new('RGBA', (width, height), (0,0,0,0))
    transparent.paste(base_image, (0,0))
    transparent.paste(watermark, position, mask=watermark)
    transparent.show()
    transparent.save(output_image_path)

if __name__ == '__main__':
    img = 'path_to_input_image /home/...'
    watermark_with_transparency(img, 'path_to_output', 'path_to_watermark', position=(0,0))

What am I doing incorrectly? Thanks for your help.

Answer 1

You are pasting an Image with no transparency in it. Being a PNG, it doesn't mean it contains transparency, but an alpha layer, in which case, every pixel is equal to 255

There is no need to make it transparent with putalpha, you just need a PNG file with the black area transparent