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Ep396: How do QR codes and Barcodes work? · Kidcast Daily

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  Spin the wheel, let's take a ride.
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  Sports and science bursting from inside a world of wonder.
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  Open wide. Come on kids, let's amplify kid
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  cats. Daily starts your day, Fun and
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  laughter come your way. Sports and Trinia games galore.
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  Greetings curious explorers. This is Kickass Daily, your
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  daily adventure through science, sports, world history, cool
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  inventions and everything in between.
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  Today we are unlocking the secrets behind those black and
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  white lines on packages and the square pixel patterns you see on
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  posters, tickets and screens. So let's get on with today's
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  episode. First up, barcodes.
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  A barcode is a set of black bars and white spaces printed on
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  items like cereal boxes, books, and toys.
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  Those bars are not random. They're a way to write numbers
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  using different widths of bars and spaces.
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  When a cashier slides a product over the scanner, the scanner
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  shines light on the bars and measures how much light bounces
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  back from the white gaps versus the black lines.
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  That pattern of light and dark turns into numbers in a
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  computer. Those numbers match a product in
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  the store's database, like chocolate chip cookies 300
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  grams. The screen shows the price and
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  the store updates its inventory count.
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  A common type in the United States and Canada is called
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  UPCA. It usually holds 12 digits.
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  Most of those digits identify the brand and the item.
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  One special digit at the end is the check digit.
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  The check digit is calculated from the other digits using
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  simple math. If the scanner reads the bars
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  incorrectly, the math will not work out and the system knows
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  something is wrong. This helps avoid mistakes at
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  checkout. Barcodes are called 1
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  dimensional or 1D because the data runs in One Direction left
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  to right. You can only fit a small amount
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  of information that way, usually just a set of numbers.
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  That is actually good enough for a lot of tasks in a store.
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  The barcode does not need to say the product name or price
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  itself, it only needs to hold the ID number.
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  The computer in the store looks up the rest.
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  How does the scanner actually read it?
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  Early scanners used a tiny red laser that sweeps across the
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  lines. The sensor sees bright
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  reflections from white spaces and dark from black bars.
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  Newer scanners and phone apps use camera images and software
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  to find the bars and decode the widths.
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  The software also checks for quiet zones, which are blank
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  spaces on the left and right sides that mark where the
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  barcode starts and ends. Did you know many barcodes can
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  be read even if they're on curved surfaces like a bottle
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  label, as long as the bars are not too distorted and the quiet
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  zones are clear? Now let's talk about QR codes.
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  QR stands for a quick Response, a type of two-dimensional code
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  that stores data in rows and columns of tiny squares instead
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  of bars. Those squares are called
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  modules. Because they go both across and
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  down. QR codes can store much more
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  data than a 1D barcode. They can hold website links,
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  short messages, phone numbers, or even a small contact card.
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  When you point your phone camera at a QR code, the app finds the
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  big square markers in three corners.
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  Those are called Finder patterns.
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  They help the software locate the code, set the alignment and
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  figure out the size. Then the app reads the pattern
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  of black and white modules and turns it back into text or a web
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  address. QR codes have built in error
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  correction. This means the code includes
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  extra math based data so the reader can fix some mistakes
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  caused by dirt, scratches or folds.
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  Depending on the error correction level, AQR code can
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  often still be read even if part of it is damaged.
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  Did you know some QR codes include alignment squares inside
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  the grid to help the reader handle slight bending or camera
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  angles? Here is a real life example you
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  might have used at a museum. A sign might have a QR code next
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  to a painting. You scan it and your phone opens
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  a page with the artist's name, the year it was painted, and a
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  short audio guide at a sports stadium.
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  Your ticket might be AQR code on your phone screen.
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  The gate scanner checks the pattern to match your seat and
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  game time. In both cases, the code is just
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  a fast way to pass data from paper or a screen to a computer.
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  Time for a quick trivia challenge.
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  What does the QR and QR code stand for?
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  It stands for Quick Response. The code was designed to be
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  scanned quickly and to hold more information than older 1D
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  barcodes. Here is another neat detail.
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  QR codes come in versions that control how many modules are in
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  the grid. Version one is 21 by 21 modules
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  and the size grows by 4 modules per side each version.
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  Higher versions can hold more characters.
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  The more data you try to store, the denser the pattern becomes
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  and the smaller the modules need to be if you want to keep the
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  code the same physical size on the page.
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  That is why very busy QR codes can be hard to scan if they are
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  printed too small. Let's check your observation
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  skills with a yes or no question.
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  Can a QR code be scanned even if you hold your phone at an angle
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  or upside down? Yes.
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  The Finder patterns in the corners let the software figure
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  out the orientation. The reader rotates and corrects
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  the image before decoding. Barcodes and QR codes are often
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  used together in the same places.
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  A shipping box might have a 1D barcode for quick, rugged
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  scanning in a warehouse and a QR code that links to a web page
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  with detailed instructions. Barcodes are great for speed
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  when you only need an ID number. QR codes are great when you need
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  to pack more data into a small space or when people will scan
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  with smartphones. Let's add some safety and
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  etiquette tips. You should only skin codes from
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  sources you trust. If a QR code is stuck over
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  another code on a public sign, that could be misleading.
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  On phones, you can often preview the web link before opening it.
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  At school events and libraries, staff usually provide official
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  codes on printed signs or screens.
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  Did you know many camera apps show the website address on
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  screen before you tap so you can confirm it looks right?
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  Want a cool historical nugget? Did you know the very first
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  product ever scanned with a barcode at a checkout in 1974
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  was a pack of Wrigley's Juicy Fruit chewing gum in Ohio?
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  That moment showed stores that machine reading could speed up
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  lines and track inventory more accurately.
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  Here comes a yes or no tech question that might surprise
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  you. Does a QR code always need the
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  Internet to work? No, the code itself stores the
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  data. If the data is just text or a
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  phone number, your device can show it without Internet.
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  You only need Internet if the code points to a web page or
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  needs to fetch something online. You can even make your own
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  codes. Many websites let you type text
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  or a link and download a printable QR code.
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  If you do this for a school project, make the printed code
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  at least a couple of centimeters wide and leave a quiet zone of
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  blank space around it. High contrast matters.
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  Black modules on white paper are easiest to scan.
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  If you must use color, choose a dark color for modules and a
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  very light background. Now a final trivia question to
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  round out your knowledge. Which country was the birth
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  place of the QR code? Japan.
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  It was created in 1994 by a company called Denso Wave to
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  track parts and factories, and later it spread to many other
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  uses around the world. Here is a quick experiment you
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  can try at home with an adult's permission.
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  Find a cereal box with a barcode and try scanning it with a free
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  barcode app. You will likely see a number
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  called a GTN, which stands for Global Trade Item Number.
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  Now print a simple QR code that shows a short message like Hello
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  from Science Club. Tape it on a notebook and scan
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  it with your phone camera. You will notice that the barcode
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  connects you to a database entry, while the QR code reveals
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  the actual message directly. Did you know some supermarket
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  scanners can read barcodes from any direction because they use
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  multiple laser lines or camera sensors that crisscross the
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  code? This helps items get faster
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  without having to line them up perfectly.
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  Before we wrap up, here is one more question to test a fresh
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  detail you have not heard yet. Could a store use a barcode that
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  encodes letters instead of only numbers?
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  Yes. Some barcode types like code 128
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  and code 39 can encode letters and symbols, not just digits.
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  UPC is mainly numeric, but other formats are more flexible.
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  Let's recap what we learned today.
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  Bar codes are 1D patterns of bars and spaces that usually
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  hold numbers with a check digit to catch errors.
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  Scanners use light or cameras to read them quickly, making
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  checkout and inventory fast and accurate.
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  QR codes are 2D grids of modules with Finder patterns for
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  alignment and error correction to handle some damage.
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  They can store more information like links or text, and
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  smartphone cameras can read them from different angles.
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  We talked about real uses like tickets, museum signs, and
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  shipping. We shared that QR stands for
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  Quick Response started in Japan, and that QR codes do not always
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  need the Internet. We also learned that some
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  barcode types can include letters.
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  Next time you see lines on a box or a square of tiny squares on a
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  poster, you will know exactly how your device turns those
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  patterns into useful information.
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  Thanks for exploring with me, and keep your curiosity switched
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  on for tomorrow's adventure grab.
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  Your breakfast feelings, fine adventures waiting.
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  Don't be late. Today's.
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  The day we celebrate.