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Images are a great way to communicate without text but oftentimes images are used/abused to spread text within social media and advertisements. Text in images also presents an accessibility issue. The truth is that it’s important, for any number of reasons, to be able to detect text in image files. The amazing open source tool that makes detecting text in images possible is tesseract OCR!

I recommend using Homebrew to install tesseract:

brew install tesseract

To run tesseract to read text from an image, you can run the following from command line:

tesseract ~/Downloads/MyImage.png ~/Downloads/MyImage.txt -l eng

The command above extracts detected text in the English language (-l eng) into a text file (MyImage.txt). The process is very quick and there are dozens of supported languages.

Let’s look at the following example:

The following text is detected:

International
‘Champions
Cup

~- TOUR SQUAD

#AFCTour2018

CECH MUSTAFI GUENDOUZI oziL
LENO SOKRATIS NELSON IWOBI
MARTINEZ MAVROPANOS SMITHROWE = NKETIAH
BELLERIN OSEI-TUTU WILLOCK PEREZ
KOLASINAC ELNENY RAMSEY LACAZETTE
CHAMBERS MAITLAND-NILES MKHITARYAN AUBAMEYANG
HOLDING

There are a number of utilities in different programming languages that plug into tesseract’s functionality, but it’s important to know the underlying tool! tesseract is an unbelievable tool that you should take advantage of if you need an open source utility for detecting text in an image!

The post How to Detect Text in Images appeared first on David Walsh Blog.

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One of my biggest mistakes with this blog was not finding a WordPress plugin that would allow me to write my posts with markdown; to this day I still need to write posts in “Visual” mode and then manually convert the post to HTML for “Text” mode.  One of these days I want to convert existing posts to Markdown and then enable a plugin that will convert Markdown to HTML. This painful process made me ask myself:  is there a way I can use Node.js JavaScript to convert HTML to Markdown?  There is, and it’s called Turndown by Dom Christie.

Convert HTML to Markdown with Node.js

Start by installing Turndown:

yarn add turndown

Then use Turndown’s simple API to convert HTML to markdown:

var TurndownService = require('turndown');
var turndownService = new TurndownService();

var markdown = turndownService.turndown(`
    Title
    

DavidWalsh.Name is awesome!

`); /* Title ===== [DavidWalsh.Name](https://davidwalsh.name) is awesome! */

You can use the interactive Turndown demo to experiment with its capabilities.  Turndown has a number of options and allows you to use filters to keep elements you believe could be at risk for improper conversion.

Most developers look for a Markdown to HTML solution so it’s rate to find myself in a position to need to convert HTML to Markdown.  I look forward to migrating my site’s content to Markdown so that writing posts is much less stressful in the future!

The post Convert HTML to Markdown appeared first on David Walsh Blog.

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URL shorteners are a dime a dozen these days, and it is quite nice to have a pretty URL instead of a mile long string, but there are some downsides to URL shorteners:  they can mask dangerous URLs and getting to the endpoint can be slow, since you end up making multiple requests.  And what if a shortener sold out to a porn company?!  Whoa!

A while back I wrote a post about following URLs from command line with cURL.  Since I love JavaScript and Node.js is in full flight, I want to show you linkfollower, a Node.js utility for following URL redirects and getting the final landing URL.

Start by installing linkfollower:

yarn add linkfollower
# or `npm install linkfollower`

With linkfollower installed globally, we can use the follow command to follow the series of redirects until the final URL:

# follow {url}
follow http://davidwalsh.name/css

# RESULT:
# http://davidwalsh.name/css -> 301
# https://davidwalsh.name/css -> 301
# https://davidwalsh.name/css-animation-callback -> 200

URL shorteners can be likened to a blindfold — the promise of going one place but possible end up in another.  Using linkfollower is a good practice if you care to be secure with links.

The post Follow URL Redirects with Node.js appeared first on David Walsh Blog.

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