I put a two-dimensional code with rainbow candy

I don't know when , QR code has become an indispensable part of our life , Pay to scan QR code , Scan QR code by bike , Even the necessary health code for our recent trip is a two-dimensional code .

The word "green" has a richer meaning , I am green , And you? …

Today, I'm going to challenge you to use rainbow candy to lay out a QR code that you can scan , But now I have no idea , Let's check whether it is feasible ~

We all know that QR code is a combination of binary arrays , The most common is this kind of two-dimensional code with black and white , Each little black square represents 1, The small white square represents 0.

But in fact, this square can not only match black and white , Red and white 、 Red and green can also be matched , Only two colors are needed to have contrast .

Even this black block is not limited to square , It can also be other shapes , Like a circle .

If the circle is colorful , That's what rainbow candy looks like .

We have to use Python Achieve it , There are wheels out there （myqr）, Let's modify it a little , That's all right. .

def draw_a_black_unit(p, x, y, ul):
    draw = ImageDraw.Draw(p)
    font = ImageFont.truetype("/Library/Fonts/Arial Unicode.ttf", 10, encoding="utf-8")
    colors = ["red","orange","green","blue","purple"]
    color = random.choice(colors)
    draw.text((x, y), '●', fill = color, font=font)

Then use the command line to generate , Rainbow sugar QR code appears ~

myqr https://space.bilibili.com/279911711

Try it with your mobile phone and you can successfully identify （ Wechat identification is difficult , I use a treasure sweep ）, It shows that our idea is feasible ~

But now there are 691 A dot , That's what we need 691 Rainbow candy , A bag of rainbow candy is about 40 star , You can't remove the yellow ones , What can be used is about 30 star , Then I just want to buy 24 package , One pack 3 Yuan ...

Poverty makes my rusty brain work quickly . How to make these dots less and save money ？

Well, we need to know something about it first , QR codes have error correction levels .

For example, I block this one , You can still scan the contents of the QR code , It means that it is OK if the block is not blocked .

The lower the error correction level is , The less points you have left , So the first thought , Reduce the error correction level of QR code .

Now there is a lot less , But there is still 446 A dot , It's still beyond my budget ...

To further reduce the number of dots , You should know that the last step of the QR code will be handled with a mask , Avoid large areas of blank or black blocks , Affect scanning code recognition .

Now there is 8 Masks of different styles , The system will rate these masks , Select the mask with the best 2D code fragmentation .

But we just play by ourselves , There is no need to choose the best mask , Let's choose the mask with the least number of QR code points to export ~

Continue to change the code

def mask(mm, m):
    mps = get_mask_patterns(mm)
    scores = []
    for mp in mps:
        score = 0
        for i in range(len(mp)):
            for j in range(len(mp)):
                mp[i][j] = mp[i][j] ^ m[i][j]
                if mp[i][j] == 1:
                    score += 1
        scores.append(score)
    best = scores.index(min(scores))

That's it , Now we still need 414 A rainbow candy , It seems that there is not much less …

No problem , I have one last move , Is to shorten the URL , Find a website that will B The website of the home page of the station will be converted

Let's take a look at the generation

Obviously a lot less , Now it's just a matter of 310 A rainbow candy , With the original 691 It saves more than half of the money ~

Let's try the real thing now ！

I put a two-dimensional code with rainbow candy ...

Be accomplished ~

The only regret is that the converted short link is invalid , You can't jump to B Standing on the web page .

And it's easier to identify with Taobao , Wechat is difficult , You have to find an angle …