Tag Archive for 'integral image'

Adaptive Thresholding using Integral Image [source]

Adaptive Thresholding

I have to admit that built in Flash methods is really fast in processing time and I cant beat the speed of blurred adaptive thresholding versions provided by Mario and Saqoosha. I still think it could perform faster… ;) Talking about thresholding result I cant say which one is more accurate – try it yourself.
Continue reading ‘Adaptive Thresholding using Integral Image [source]‘

Extended Adaptive Thresholding

Adaptive Thresholding

As I’ve mentioned in my previous post I was in search for better thresholding methods. Automated Thresholding (auto switch of threshold value using image histogram) is good but not enough for better pattern recognition and other stuff. All of you know know that next level is Adaptive Thresholding. Mario have shown this method in his post. But his adaptive method is not enough for our needs too! It uses slightly blurred image (extra compute time) and pass everything to pixel bender filter. The result is good but what if I tell you we can do better and faster! ;)
I’ve searched a lot before I found an article on combining Wellner’s thresholding algorithm with integral image data for better results, specially for pattern recognition! This technique was discovered by Derek Bradley and Gerhard Roth. And the best news is that it can work really fast and accurate in pure AS3 without any blurred images and pixel bender stuff! Sure it can be adopted to run even faster if we move render code to pixel bender but I guess it will be up to users itself (truly it will save 3ms not much).

See demo application (you will need web camera and Flash 10 installed)
Get the source code

More screenshots:

Adaptive Thresholding
Adaptive Thresholding
Adaptive Thresholding
Adaptive Thresholding