Adafruit will not be shipping orders Martin Luther King Jr. Day, Monday January 21, 2019. Any expedited orders placed after 11am ET Friday January 18 will go out Tuesday January 22.
0

The Floyd-Steinberg Dithering Algorithm for Thermal Paper Printing #Java

If you’ve ever converted an image to GIF and restricted its color table to 256, you effectively employed the Floyd–Steinberg dithering algorithm. For thermal printers – where the background is typically white and black is probably your only ink color – the challenges are different but you can still achieve remarkable results. Thankfully Pierre Muth walks through the process, all stemming from his Free Beer Selfie project.

To print pictures on thermal paper with reasonably good rendering, they should be converted according the printer limitations. It’s quite simple, it can be printed only black pixels (and whites as the paper is usually white).

img_3696

As receipt thermal printer use paper roll, there is virtually no image length limit. If we want to convert on the fly the image and strait print it, we cannot rely on a fixe full image sized buffer. That’s why I experimenting conversion algorithm based on Floyd-Steinberg, but with only a small rotating buffer. The size of this ‘line’ buffer could be as small as a line size plus one.

Other than the code itself, I try to explain the principle with this Gif :

dither

Read more.


Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, or even use Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for MakeCode, CircuitPython, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.

Join 9,700+ makers on Adafruit’s Discord channels and be part of the community! http://adafru.it/discord

What do you want from CircuitPython in 2019?

Have an amazing project to share? Join the SHOW-AND-TELL every Wednesday night at 7:30pm ET on Google+ Hangouts.

Join us every Wednesday night at 8pm ET for Ask an Engineer!

Follow Adafruit on Instagram for top secret new products, behinds the scenes and more https://www.instagram.com/adafruit/


Maker Business — A field guide to designing your PCBs, learned the hard way

Wearables — 5 meter fun

Electronics — Current limiting!

Biohacking — A Gene to Predict Modafinil Response

Python for Microcontrollers — Python snakes its way on the SparkFun SAMD21 Mini, Hackaday.io, 10k thanks, and Tim’s magazine #Python #Adafruit #CircuitPython @circuitpython @micropython @ThePSF @Adafruit

Get the only spam-free daily newsletter about wearables, running a "maker business", electronic tips and more! Subscribe at AdafruitDaily.com !



No Comments

No comments yet.

Sorry, the comment form is closed at this time.