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I am planing to develop an app like Word Lens. Can any one suggest a good library that I can use? or any one explain technology behind the Word Lens App? is it reel time image matching or OCR? I know some image processing library like OpenCv, tesseract...Any help is greatly appreciated...
I'm one of the creators of Word Lens. Although there are some OCR libraries out there (like tesseract), we decided to make our own in order to get better results and performance. Our general algorithm goes like this:
copy the image from the camera and get its grayscale component
level out the image so the text stands out clearly against the background
draw boxes around things that look like characters & sentences
do OCR: match the pixels in each box against a database of characters -- this is actually pretty hard!
collect the characters into words, look up in a dictionary (this is hard too, because there will be mistakes in the OCR)
draw the results back onto the image
Image matching by itself is not good enough, because of the huge variety of fonts, words, and languages out there.
OpenCV is a great library to get up and running with, and to learn more about computer vision in general. I would recommend building off their examples, and playing around there. Have fun!
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I am developing a video game in unity 2D but I need to know which are the best applications to create pixel art
Here is a short list of what came to my mind, it is by far not complete.
You can use MS Paint with the Magnifier to create precise pixel art, but it does not support shadowing etc. If you use JPEG, every save-action will add more JPEG artifacts.
Paint.net is free and powerful, a good alternative to the limited MS Paint.
Photoshop also shows the pixel grid if you zoom in, but MOST tools and brushes are not really suitable for pixel art, in my opinion.
Kenney.NL aka "Asset Jesus" has a lot of free packs, also a few tools, of which I would recommend KenShape (https://tools.kenney.nl/kenshape/) for pixel art. (edit: I think that only generates 3D voxel models... whoops)
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I saw this feature in many children apps where the word magnified when the reader read it. i want to know how it was achieved in swift here is an example:
https://youtu.be/Hv0In39r2so
I have no idea what I've to seach for to learn about it
It's hard to be sure. in the example you linked it looks like it's drawing a highlighing rectangle with a drop shadow behind the text rather than magnifying it.
You could use attributed strings (NSAttributedString) to highlight each word in bold, for example. I'm not sure how you would synchronize the highlighting with the spoken text however. You might need to create an array of time indexes for the time when the audio begins speaking each word in the text, along with a range for each word to be highlighted. You could then apply bolding (or other styling changes) to one word at a time as each time index passes.
If you wanted to use a highlighting box as in the video you'd probably have to use CoreText. This link should get you started, but be warned that CoreText is complicated. It is not a beginner framework.
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Is there any good Scala or Java library for image manipulation? For simple tasks like composing an image with some others then generating a thumb?
Take a look at https://github.com/sksamuel/scrimage (Disclaimer: I am the author)
This is an open source Scala image library that essentially wraps java.awt Image operations in a nicer API.
You asked how to generate a thumbnail, you would do something like.
val in = ...// some input stream
val out = ... // some output stream
Image(in).scale(300,400).write(out, Png)
You can change the scaling method (Bicubic by default) and the output format.
they're all a bit old school, and maybe inconvenient, but java.awt, java.awt.image, and javax.imageio has everything you need to blend and rescale images. You can find some blending example code e.g. here
http://www.curious-creature.org/2006/09/20/new-blendings-modes-for-java2d/
you can find some examples of rescaling and generating image bytes e.g. here
https://sourceforge.net/projects/ssim/?source=directory
there are probably newer/easier solutions, but these do work.
It's not Scala-specific, but ImgLib2 is a full-powered Java image processing library. It's geared towards scientific/low level use, so it might not be as easy as you want for what you're looking for, but it can almost certainly manage anything you're likely to want.
There are also a lot of nice image filters in this Open Source library:
http://www.jhlabs.com/ip/filters/
Since the question is tag with java-2d you know you can use any Java library. A quick google revealed this SO answer:
open source image processing lib in java
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Does anybody know which,currently,is the best library for realizing a real time face-tracking solution for iPhone? I've done a research but I've found quite old articles about OpenCV portings. I would like to know if there is any specific,reliable,fast (and possibly free) AR solution for overlay in real time an image to the face in iPhone camera Video Stream (not simply a static image)
Any help (link,tutorial) would be great.
Thanks everybody!!
Elos
iOS 5 brings facial recognition as a native feature.
Basically you just have to configure an object to act as your the video output stream’s delegate (could be your controller, for example) and use a CIDetector object to process this stream (which is a class available only in iOS 5).
This CIDetector object will look for the faces in each of your video's frame and return a CIFaceFeature object with several information about the faces found, such as the eyes and mounth position and also the bounds (the rectangle that the face was found inside).
You can check this blog for more implementation details:
https://web.archive.org/web/20130908115815/http://i.ndigo.com.br/2012/01/ios-facial-recognition/
opencv is the best i think.
checkout this tutorial:
http://www.morethantechnical.com/2009/08/09/near-realtime-face-detection-on-the-iphone-w-opencv-port-wcodevideo/
https://github.com/beetlebugorg/PictureMe
a starting point... he's using opencv.
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I am looking for information on how to draw flame fractals from googling around I could not find much, either pages explain how to use third party tools or way too complicated for me to grasp. Anyone know how/why they work? or point me in the direction of not overly complicated implementations?
I have written a beamer presentation that covers the basics in flame fractals:
https://www.math.upenn.edu/~peal/files/Fractals[2009]Beamer[Eng]-PAXINUM.pdf
All images are done from my java implementation of the flame algorithm.
The source code can be found here:
http://sourceforge.net/projects/flamethyst/
I believe that the pdf http://flam3.com/flame_draves.pdf together with the implementation in java above should get you a long way.
You could read the original paper by Scott Draves, which details precisely how and why they work, as well as a guide to an implementation in pseudocode.
As long as you have some basic knowledge of maths, it should be relatively straightforward to understand (though it is rather long!). To be honest, you can probably ignore much of it and just read about the code, since much of the text is background info.
Fractal flames are basically a variant of an iterated function system (IFS). You have a series of functions through which you pass a single point over and over again. Each function is a combination of an affine transformation and one or more variations.
Each iteration, only one function is chosen (at random), and the resulting point is accumulated into a buffer and used as the starting point of the next iteration.
The buffer is then saved as an image, after having been post-processed and filtered, as described in the flame paper.
The best reference is still the original implementation, flam3.
I think fractals would be too computationally expensive to do in real time.
If I Google "simulating fire in computer graphics" I get a number of interesting things that suggest that it's not a trivial problem (surprise). SIGGRAPH is a conference whose proceedings you'll want to check out. But be warned - this is very mathematically challenging.
Have a look at http://formulas.ultrafractal.com/
There you can download the "Completed Formula Pack"
The file enr.ucl file should contain the formula for the flame fractal.
For more info:
http://www.ultrafractal.com/kb/flamefractals.html