Add watermark to an Image using Python Pillow

python-pillow-image-watermark.py

from PIL import Image, ImageDraw, ImageFont

# open image to apply watermark to
img = Image.open("watermark_test.jpg")
img.convert("RGB")

# get image size
img_width, img_height = img.size

# 5 by 4 water mark grid
wm_size = (int(img_width * 0.20), int(img_height * 0.25))
wm_txt = Image.new("RGBA", wm_size, (255, 255, 255, 0))

# set text size, 1:40 of the image width
font_size = int(img_width / 40)

# load font e.g. gotham-bold.ttf 
font = ImageFont.truetype(path.format("gotham-bold.ttf"), font_size)
d = ImageDraw.Draw(wm_txt)

wm_text = "Kuma Kum"

# centralize text
left = (wm_size[0] - font.getsize(wm_text)[0]) / 2
top = (wm_size[1] - font.getsize(wm_text)[1]) / 2

# RGB(0, 0, 0) is black
# Alpha channel specifies the opacity for a color
alpha = 75
d.text((left, top), wm_text, fill=(0, 0, 0, alpha), font=font)

# uncomment to rotate watermark text
# wm_txt = wm_txt.rotate(15,  expand=1)
# wm_txt = wm_txt.resize(wm_size, Image.ANTIALIAS)

for i in range(0, img_width, wm_txt.size[0]):
    for j in range(0, img_height, wm_txt.size[1]):
        img.paste(wm_txt, (i, j), wm_txt)

# save image with watermark
img.save("watermark-image-1.jpg")

# show image with watermark in preview
img.show()