问题
I got a square logo and I need to round_corner it, searched for a while and got the follow code "working":
def round_corner_jpg(image, radius):
"""generate round corner for image"""
mask = Image.new('RGB', image.size)
#mask = Image.new('RGB', (image.size[0] - radius, image.size[1] - radius))
#mask = Image.new('L', image.size, 255)
draw = aggdraw.Draw(mask)
brush = aggdraw.Brush('black')
width, height = mask.size
draw.rectangle((0,0,width,height), aggdraw.Brush('white'))
#upper-left corner
draw.pieslice((0,0,radius*2, radius*2), 90, 180, None, brush)
#upper-right corner
draw.pieslice((width - radius*2, 0, width, radius*2), 0, 90, None, brush)
#bottom-left corner
draw.pieslice((0, height - radius * 2, radius*2, height),180, 270, None, brush)
#bottom-right corner
draw.pieslice((width - radius * 2, height - radius * 2, width, height), 270, 360, None, brush)
#center rectangle
draw.rectangle((radius, radius, width - radius, height - radius), brush)
#four edge rectangle
draw.rectangle((radius, 0, width - radius, radius), brush)
draw.rectangle((0, radius, radius, height-radius), brush)
draw.rectangle((radius, height-radius, width-radius, height), brush)
draw.rectangle((width-radius, radius, width, height-radius), brush)
draw.flush()
del draw
return ImageChops.add(mask, image)
then I saved the returned image object,however it has white background in the corner like this How can i get rid of the white background or make it invisible? Thanks in advance~
EDIT: here is the code by fraxel,thanks~
def add_corners(im, rad):
circle = Image.new('L', (rad * 2, rad * 2), 0)
draw = ImageDraw.Draw(circle)
draw.ellipse((0, 0, rad * 2, rad * 2), fill=255)
alpha = Image.new('L', im.size, "white")
w, h = im.size
alpha.paste(circle.crop((0, 0, rad, rad)), (0, 0))
alpha.paste(circle.crop((0, rad, rad, rad * 2)), (0, h - rad))
alpha.paste(circle.crop((rad, 0, rad * 2, rad)), (w - rad, 0))
alpha.paste(circle.crop((rad, rad, rad * 2, rad * 2)), (w - rad, h - rad))
im.putalpha(alpha)
return im
if __name__ == '__main__':
im = Image.open('1.jpg')
im = add_corners(im, 100)
im.save('out.png')`
I am so sorry..I need the image shape to be ellipse not rectangle,I.E. the write stuff off the pic,and @fraxel, I still can see the white corner in the pic you processed for me
回答1:
First off, make sure you are saving your image in a format that supports transparency. PNG does, JPG does not... Below is some pretty nice code that will add transparent corners. It works like this:
- Draws a circle with radius,
rad, usingdraw.ellipse() - Create an image for the alpha channel the same size as your image
- Chop our circle into four pieces (the rounded corners), and place them in the correct corners of the alpha image
- Put the alpha channel into your image using
putalpha() - Save as a
png, thus preserving transparency.
Here is the code:
import Image, ImageDraw
def add_corners(im, rad):
circle = Image.new('L', (rad * 2, rad * 2), 0)
draw = ImageDraw.Draw(circle)
draw.ellipse((0, 0, rad * 2, rad * 2), fill=255)
alpha = Image.new('L', im.size, 255)
w, h = im.size
alpha.paste(circle.crop((0, 0, rad, rad)), (0, 0))
alpha.paste(circle.crop((0, rad, rad, rad * 2)), (0, h - rad))
alpha.paste(circle.crop((rad, 0, rad * 2, rad)), (w - rad, 0))
alpha.paste(circle.crop((rad, rad, rad * 2, rad * 2)), (w - rad, h - rad))
im.putalpha(alpha)
return im
im = Image.open('tiger.jpg')
im = add_corners(im, 100)
im.save('tiger.png')
example curved edge tiger:
here is your image, processed with this code, giving transparent corners:
回答2:
Have you tried something like image.putalpha(mask) to replace the image's alpha channel with the mask? This seems like it should do what you want. mask might have to be in 'L' mode for this to work correctly, and image should probaby be 'RGBA', but might be automatically converted for you.
The top answer here provides some good examples: How do I generate circular thumbnails with PIL?
Your mask image looks fine, but I think you want to swap 'white' and 'black', so you have a white rounded rectangle exactly the shape you want your final image to be, on a black background. You will probably also need to use the 'L' mode (greyscale) one.
Once you have this image, you can replace the return ImageChops.add(mask, image) by image.putalpha(mask); return image and this should cause the image to be transparent in only the black areas of the mask.
You might need to convert the image first with image.convert('RGBA') but I think this is unnecessary in later versions of PIL, it does it automatically.
Something like: (sorry can't test this right now)
def round_corner_jpg(image, radius):
"""generate round corner for image"""
mask = Image.new('L', image.size) # filled with black by default
draw = aggdraw.Draw(mask)
brush = aggdraw.Brush('white')
width, height = mask.size
#upper-left corner
draw.pieslice((0,0,radius*2, radius*2), 90, 180, None, brush)
#upper-right corner
draw.pieslice((width - radius*2, 0, width, radius*2), 0, 90, None, brush)
#bottom-left corner
draw.pieslice((0, height - radius * 2, radius*2, height),180, 270, None, brush)
#bottom-right corner
draw.pieslice((width - radius * 2, height - radius * 2, width, height), 270, 360, None, brush)
#center rectangle
draw.rectangle((radius, radius, width - radius, height - radius), brush)
#four edge rectangle
draw.rectangle((radius, 0, width - radius, radius), brush)
draw.rectangle((0, radius, radius, height-radius), brush)
draw.rectangle((radius, height-radius, width-radius, height), brush)
draw.rectangle((width-radius, radius, width, height-radius), brush)
draw.flush()
image = image.convert('RGBA')
image.putalpha(mask)
return image
来源：https://stackoverflow.com/questions/11287402/how-to-round-corner-a-logo-without-white-backgroundtransparent-on-it-using-pi