QRCodeGenerator(size, message)

eduairet

Hi DrawBot fellas!!

I'm struggling with the QRCodeGenerator() ImageObject() property, I got two errors, the first one is TypeError: Expecting byte-buffer, got str when I try to pass a URL, and when I try to encode the URL TypeError: cannot unpack non-iterable float object

Is it possible that you can help me to figure out what's happening?

Here's the way I'd love to use it:

path = 'https://www.mypath.com'

newPage(1000, 1000)
qr = ImageObject()
path = path.encode('utf-8')
qr.QRCodeGenerator(100, path)

image(qr, (0, 0, width(), height()))

And here's the way I made it with the qrcode module by making a png first and then using it inside my drawbot image

import qrcode
path = 'https//:www.mypath.com'
qr = qrcode.QRCode(
    version = 1,
    error_correction = qrcode.constants.ERROR_CORRECT_L,
    box_size = 40,
    border = 0,
)
qr.add_data(path)
qr.make(fit=True)
img = qr.make_image(fill_color='black', back_color='white')
qrpath = 'myQr.png'
img.save(qrpath)
image(qrpath, (0, 0))

Thank you!!!

gferreira

hello @eduairet,

when working with QRCodeGenerator:

data must be in bytes
size must be a tuple

this works:

path = bytes('http://www.drawbot.com/', 'utf-8')

w, h = 31, 31

img = ImageObject()
img.QRCodeGenerator((w, h), path, 'Q')

size(w, h)
image(img, (0, 0))

the third parameter (L, M, Q or H) determines the correction level, see the Core Image docs for more info.

hope this helps! cheers

ps. the resulting image is tiny (1 pixel per bit). you can scale it by reading the pixel values and redrawing it with shapes:

path = bytes('http://www.drawbot.com/', 'utf-8')

w, h = 31, 31
s = 10

img = ImageObject()
img.QRCodeGenerator((w, h), path, 'Q')

size(w*s, h*s)
for x in range(w):
    for y in range(h):
        c = imagePixelColor(img, (x, y))
        fill(*c)
        rect(x*s, y*s, s, s)

eduairet

@gferreira WOW!!!! you saved my ass again, you're amazing, thanks a lot!!!

frederik

maybe the callback should convert incoming str to bytes, or the docs must change. Im make an issue --> https://github.com/typemytype/drawbot/issues/411

monomonnik

Using almost the exact same script of @gferreira (only added the generated image on top of the shapes) I get a QR code that is not very crisp.

Am I doing something wrong? Or has something changed since 2020?

path = bytes('http://www.drawbot.com/', 'utf-8')

w, h = 31, 31
s = 10

img = ImageObject()
img.QRCodeGenerator((w, h), path, 'Q')

size(w*s, h*s)
for x in range(w):
    for y in range(h):
        c = imagePixelColor(img, (x, y))
        fill(*c)
        rect(x*s, y*s, s, s)

image(img, (0, 0))

frederik

no idea... but the image is indeed blurry. A quick search for CoreImage filter CIQRCodeGenerator + blurry results in lots of options but none of them apply to DrawBot.

I would look at some python packages like https://github.com/mnooner256/pyqrcode to build the QR data and draw it with DrawBot, without round tripping to a png or image

good luck!

frederik

in the pip installer: pyqrcode --no-deps

import pyqrcode

blockSize = 10

qr = pyqrcode.create('http://www.drawbot.com/')

for x, row in enumerate(qr.code):
    for y, bit in enumerate(row):
        if bit:
            rect(x * blockSize, y * blockSize, blockSize, blockSize)
        
print(qr.code)

monomonnik

Thanks @frederik

jo

I ran into the same issue a few weeks ago and @frederik actually posted another solution in the other QR code thread:
going through the pixels and checking the lightness/brightness:
https://forum.drawbot.com/topic/397/qr-code-with-type?_=1681732270808

Using a module has the nice advantage of checking the size of the QR code after generating it.

frederik

hehe, totally forgot about that one... but I prefer the solution with pyqrcode as it provides a list 0/1