Artificial Neural Networks (ANN) can be complex but it has become much easier to implement, thanks to frameworks and libraries, the past few years. In this post, we’ll walk through the process of creating a basic ANN. We’ll be using Python, TensorFlow, and Keras to create an ANN for recognizing handwritten digits. This is kind of the “Hello World” of AI.
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Writing a business card reader can be tedious. I first tried using Tesseract, an open-source Optical Character Recognition (OCR) engine. But besides OCR, you still need to segment the images, do optical character recognition (OCR) then identify text patterns for names, title, phones, emails, etc and extract them. Quite a lot of work if you have a big stack of business cards to go through.
But thankfully, technology and especially AI has come a long way and we can use widely available AI engines such as OpenAI’s to make the job easier… unbelievably easier. In this post, we’ll go through the whole thing from start to finish.
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Business cards, those little cards with your contact information. I remember when I got my first box, I felt like a complete office professional! Giving and receiving them was a stringent ritual. I even had business card holders and organizers. But that was a long time ago. Do people still use those?!?
Well, apparently they still do. Yesterday, I got a big stack from my wife from her Singapore trip and she asked if I can encode the data into a spreadsheet. So me being me, instead of spending some time encoding, I spent a bit more time coding.
Read MoreI encountered an issue with Ionic side menus where a previous view would partially obscure the current view. I updated everything, checked all my JS and HTML templates, verified links and state transitions, all to no avail.
I was stuck for quite a while until I finally decided that it’s probably an iOS-specific issue. A search then led me to this Ionic blog entry from 2 months(!) ago: http://blog.ionic.io/ios-9-potential-breaking-change/. I downloaded and applied the patch and that was it.
The issue is caused by an iOS 9 bug that affects AngularJS and thus Ionic. It’s supposedly “isolated to intermittent UI/navigation issues on some apps”. And, of course, I was one of the lucky ones. I can’t believe it hasn’t been fixed yet!
I was playing around with the Firebase REST APIs when I encountered the following SSL error:
NSURLSession/NSURLConnection HTTP load failed (kCFStreamErrorDomainSSL...After some research, I found out that iOS 9 enforces App Transport Security or ATS which, according to Apple, “enforces best practices in the secure connections between an app and its back end”.
But I am using secure connections! After further research I found out that problem with the Firebase servers, specifically the SSL ciphers they allow.
By default, apps use only a specific set of ciphers for SSL communications:
TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
Setting the NSAppTransportSecurity option will include the following ciphers, which the Firebase servers do allow:
TLS_DHE_RSA_WITH_AES_256_GCM_SHA384
TLS_DHE_RSA_WITH_AES_128_GCM_SHA256
TLS_DHE_RSA_WITH_AES_256_CBC_SHA256
TLS_DHE_RSA_WITH_AES_256_CBC_SHA
TLS_DHE_RSA_WITH_AES_128_CBC_SHA256
TLS_DHE_RSA_WITH_AES_128_CBC_SHA
TLS_RSA_WITH_AES_256_GCM_SHA384
TLS_RSA_WITH_AES_128_GCM_SHA256
TLS_RSA_WITH_AES_256_CBC_SHA256
TLS_RSA_WITH_AES_256_CBC_SHA
TLS_RSA_WITH_AES_128_CBC_SHA256
TLS_RSA_WITH_AES_128_CBC_SHASetting the NSAppTransportSecurity option entails adding the following into the app’s Info.plist:
<key>NSAppTransportSecurity</key>
<dict>
<key>NSExceptionDomains</key>
<dict>
<key>firebaseio.com</key>
<dict>
<key>NSIncludesSubdomains</key>
<true/>
<key>NSThirdPartyExceptionRequiresForwardSecrecy</key>
<false/>
</dict>
</dict>
</dict>DHE stands for Diffie-Hellman Exchange. ECDHE stands for Elliptic-Curve Diffie Hellman Exchange. They both offer forward secrecy but ECDHE is just faster. So the NSThirdPartyExceptionRequiresForwardSecrecy is a bit of a misnomer.
Now I wonder why Firebase doesn’t just add support for ECDHE?
More at StackOverflow.