OpenCV Intro to Character Recognition and Machine Learning with KNN

This video uses OpenCV 2.x and is therefore now out of date, here are some updated OpenCV 3 options depending on language preference:

OpenCV 3 KNN Character Recognition C++

OpenCV 3 KNN Character Recognition Python

OpenCV 3 KNN Character Recognition Emgu CV 3 Visual Basic

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[atlegjerse]

Thanks for the thorough lesson. Really helpful!

[swatimatta]

Please make more videos for SVM, cascades and others. Your tutorials are really helpful.

[zahareth]

Hi, Thanks for the videos they were very useful.

Can i just share a useful tip with you and with everyone else here.

I've found using templates in VS very useful, since i noticed in your videos you had re-enter all the configuration required (per project).

The way I've overcome this, is by creating a standard project template in VS. This Project Template includes all of the configuration required to run an OpenCV 3.0.0 or 2.4.11 project.

To do this:

- Create a standard opencv 3.0.0 or 2.4.11 project as per your cheat sheets.

- In VS go to: File -> Export Template and from there you can give the template a description and save it.

- Next time when you create a new opencv project, you can seletect the template you just created, give it a name, and you you dont have to enter all of the configuration in the installation cheat sheet again.

- When your new project opens up, add your source file as per usual, build and run.

I hope this was helpful to all.

[ahmedhegag]

how could you generate xml files for train and test data and then use it in the prediction?

[luckyguest]

You are brilliant Chris, very clear and detailed presentation!!I use openCV on a decaptcha .net project, but I did not train it with a set of reference char as u did, nor do I use KNN. I am using instead the inbuilt OPENCV Tesseract class along with its set of reference Tessdata files where the letter vectors are predefined. The code in vb is much more condensed and quite effective - I have around 50% success rate on 8 letters captcha after character isolation, rotation and formatting  for which I developed code myself.The vb code is a such.''Dim myOcr as Tesseract = New Tesseract("", "eng", OcrEngineMode.TesseractOnly, "0123456789")myOcr.Recognize(New Image(Of Bgr, Byte)(bitmap))Dim ocredChar as string = myOct.GetText"Have you been able to compare the merits of the 2 different approaches?All the best.

[josesilva-rodriguez]

This was awesome dude I really like this. I'm going to attempt to implement it myself and perhaps tweak it a bit. I had a question for you. You mentioned that you wanted to use an odd number in order for KNN to determine which number it is... could this perhaps work to the benefit of the machine? What I mean to say is that if you had an even amount of 0's and 8's could you throw out an exception that would prompt a user to determine what that number is so it learns more and more if it's a 0 or 8?... idk if that made sense...

[pedramkhoshnevis]

this is wonderful and so inspiring thank you.

[FrankLopezx]

hey there im new to all this opencv stuff but i must learn and looking forward to it, now at the moment i have visual studio 2013 & 2015 which of this can i use to follow along ? also i been trying to instal and run opencv 3 for use in visual studio ummm no luck with thatshit, so do you think by me following this video i can setup your version of opencv? i see is not 3 but 2.4? let me know ill be impatiently waiting lol

[ZhivkoKabaivanov]

Does the OpenCV support Unicode training?

[markusschlegel]

Trank you for your perfect tutorials! You do a great job - keep on going;-)

[mariosilva]

Hi, would anyone know how to append to the.txt files to add new characters without having to do all the training again?

[cocultrabot]

Hey how can I make invert so foreground will be blakc, background will be white

[iVandal]

How much faster is the C++ version vs the Python script?

[Bits]

Please make more videos on PIC18F, you made those videos enjoyable for micro controller newbies like me.

[MegaAbrox]

Thanks for the lesson. I notice that You have publish also other videos consider this same topic, need to check out also those. :-)

[adwitiya]

hey thanks for the video but i am unable to create classification file in linux ... please can someone help me ?

[kingame]

cannot create classifications.txt and flattened_images.txt in python script ubuntu 14.04 any solution...?

[sarpaykent]

Hey I wanna ask you something I'm using same code but I cant figure out how to make detect "i" character. It just selecting "ı" part of it

[salmanfarhat]

Please make a video on SVM . Thank you

[govindaar]

Hey,
The tutorial was amazing. I got this problem, i finish the generate data but the txt files that are created is always empty why is it so and what can i do rectify it?

OpenCV: 2.x
OS: Ubuntu 14.0.4

(Same error occurs in Windows as well)