OCR links

Today ycombination has a discussion about OCR open sources. Here are some links and product names for future reference.

ocrad.js
Tesseract with OpenCV

Torch or Caffe
https://github.com/nyanp/tiny-cnn

https://ocr.a9t9.com/

Abbyy
Omnipage
Finereader engine Abbyy for Linux looks fine
http://ocrsdk.com/plans-and-pricing/

[0] http://docs.opencv.org/3.0-beta/modules/text/doc/erfilter.ht...
[1] https://github.com/Itseez/opencv_contrib/blob/master/modules...
[2] https://github.com/Itseez/opencv_contrib/blob/master/modules...
[3] http://cmp.felk.cvut.cz/~neumalu1/neumann-cvpr2012.pdf

dlib's face detection is the best of the open-source libs, in my experience.
http://blog.dlib.net/2014/02/dlib-186-released-make-your-own...

https://github.com/creatale/node-fv
The accuracy of GOCR is very high and it doesn't require any learning.
http://manpages.ubuntu.com/manpages/dapper/man1/gocr.1.html
https://github.com/tmbdev/ocropy

https://github.com/openalpr/openalpr

http://sourceforge.net/projects/tirg/
http://libccv.org/doc/doc-swt/
https://github.com/tesseract-ocr/tesseract
https://github.com/BVLC/caffe/tree/dev/examples/mnist
https://github.com/pannous/caffe-ocr
https://wiki.apache.org/tika/TikaOCR

bash: express: command not found

After I installed express using npm install express -g

I tried to run to check the installed version
express -V

But I got
bash: express: command not found

http://expressjs.com/guide/migrating-4.html#app-gen
explains starting express v4.0, user needs to install express-generator to get express command line works well.
npm install -g express-generator

upgrade nodejs

There is a very easy way of managing your node version, using the Node binary manager module ‘n’. Another one is 'nvm' node versioning manager.

sudo npm cache clean -f  [this one doesn't work well on my Mac OSX]
sudo npm install -g n [install node binary manager]
sudo n stable [install stable version, or specify version # here like 0.10.28]

With regard to installing node, I prefer to use the homebrew package manager to install node
brew install node

node -v [check node version]
n [to list out all current installed versions, and select node version]

Reference
http://davidwalsh.name/upgrade-nodejs

Javascript code smells

Today I read about javascript code smells from http://elijahmanor.com/talks/js-smells (twitter @elijahmanor), it is really good, so summarize here.


1. Too complex
jshint maxstatements, maxdepth, maxcomplexity

jshint, eslint, jscomplexity, escomplex, jasmine

2. Copy & Paste
jsinspect, JSCPD

3. Use switch statement
Violates open/closed principle (OCP) - open for extension but closed for modification
Use Strategy design pattern

4. Magic strings
Object types, const, symbols
eslint-plugin-smells
eslint-disable

5. This abyss
that, self, me etc
Use alternatives: bind, 2nd parameter of forEach, ES6, functional programming

6. String Concat
Template strings, handlerbar, ES6
no-complex-string-concat

7. Inappropriate intimacy (tight coupled)
Dependency injection, or message broker (pub/sub)

eslint-plugin-backbone
eslint-plugin-react

http://bit.ly/js-smells

Chrome image onerror caused high CPU

We use lazy loading and onerror to handle image loading. However, the onerror fallback for a huge amount of images in DOM will cause Chrome high CPU. After pinpoint this logic, we suspect it is a Chrome rendering bug because same code works well on Firefox. Our solution is to remove the onerror fallback for list view with a lot of images.

Clean up disk spaces on Mac OSX

Except for clear system caches and temp folders, usually iPhoto Library.photolibrary takes lots of spaces. When you connect your iPhone/iPad to Macbook, it will import movies and photos through iPhoto.

I usually delete "Original Files" after creating album, or backing up to my USB drive. However, there are two folders need to clean up too except ~/Pictures/iPhoto Library.photolibrary/Masters

These two folders are:
~/Pictures/iPhoto Library.photolibrary/Previews
~/Pictures/iPhoto Library.photolibrary/Thumbnails

They are mapping to /Masters folder when import photos. If Master was deleted, we should also delete them. If you use iPhoto to delete, it should delete the Previews/Thumbnails too. But if you open Finder to delete Master files, remember to delete Previews/Thumbnails.