def add_to_image(self, im: pyvips.Image) -> pyvips.Image:
"""Add watermark to supplied image."""
LOG.info("Adding watermark '%s'", self.text)
text = pyvips.Image.text(
self.text, width=im.width, dpi=300, font=f"{self.font}"
)
text = text.rotate(self.rotate)
text = (text * self.opacity).cast("uchar")
text = text.embed(
self.x_margin,
(im.height - text.height) - self.y_margin,
im.width,
im.height,
)
if self.replicate:
text = text.replicate(
1 + im.width / text.width, 1 + im.height / text.height
)
text = text.crop(0, 0, im.width, im.height)
# we want to blend into the visible part of the image and leave any alpha
# channels untouched ... we need to split im into two parts
# guess how many bands from the start of im contain visible colour information
if im.hasalpha():
alpha = im.extract_band(im.bands - 1)
im = im.extract_band(0, n=im.bands - 1)
else:
alpha = None
if im.bands == 4:
# cmyk
text_color: Any = list(rgb_to_cmyk(self.fg_color))
elif im.bands == 3:
# rgb
text_color = list(self.fg_color)
else:
# mono
text_color = rgb_to_grayscale(self.fg_color)
LOG.info("Watermark fg_color: %s (original: %s)", text_color, self.fg_color)
im = text.ifthenelse(text_color, im, blend=True)
# reattach alpha
if alpha:
im = im.bandjoin(alpha)
return im
def add(self, im: pyvips.Image) -> pyvips.Image:
"""Use method which finds complementary color.
Returns image
"""
text = pyvips.Image.text(
self.text, width=im.width, dpi=300, font=f"{self.font}"
)
text = text.rotate(self.rotate)
# the position of the overlay in the image
margin = 25
position = self.position
if position == "top-left":
x_pos = margin
y_pos = margin
elif position == "top-right":
x_pos = im.width - text.width - margin
y_pos = margin
elif position == "bottom-right":
x_pos = im.width - text.width - margin
y_pos = im.height - text.height - margin
elif position == "bottom-left":
x_pos = margin
y_pos = im.height - text.height - margin
else:
print(f"Incorrect watermark position: {position}")
sys.exit(1)
# find the non-alpha image bands
if im.hasalpha():
no_alpha = im.extract_band(0, n=im.bands - 1)
else:
no_alpha = im
# the pixels we will render the overlay on top of
bg = no_alpha.crop(x_pos, y_pos, text.width, text.height)
# mask the background with the text, so all non-text areas become zero, and find
# the zero-excluding average
avg = avgze(text.ifthenelse(bg, 0))
# for each band, find the opposing value
mx = 255 if im.format == "uchar" else 65535
text_colour = [oppose(avg[i], mx) for i in range(len(avg))]
# make an overlay ... we put solid colour into the image and set a faded version
# of the text mask as the alpha
overlay = bg.new_from_image(text_colour)
overlay = overlay.bandjoin((text * self.opacity).cast("uchar"))
# and composite that on to the original image
im = im.composite(overlay, "over", x=x_pos, y=y_pos)
return im
def _extract_channels(im: VIPSImage, c: Optional[Union[int, List[int]]]) -> VIPSImage:
if c is None or im.bands == len(c):
return im
elif type(c) is int or len(c) == 1:
if len(c) == 1:
c = c[0]
return im.extract_band(c)
else:
channels = list(itemgetter(*c)(im))
im = channels[0].bandjoin(channels[1:])
return im
