Issue regarding practical approach on machine learning/computer vision fields - c++

I am really passionate about the machine learning,data mining and computer vision fields and I was thinking at taking things a little bit further.
I was thinking at buying a LEGO Mindstorms NXT 2.0 robot for trying to experiment machine learning/computer vision and robotics algorithms in order to try to understand better several existing concepts.
Would you encourage me into doing so? Do you recommend any other alternative for a practical approach in understanding these fields which is acceptably expensive like(nearly 200 - 250 pounds) ? Are there any mini robots which I can buy and experiment stuff with?

If your interests are machine learning, data mining and computer vision then I'd say a Lego mindstorms is not the best option for you. Not unless you are also interested in robotics/electronics.
Do do interesting machine learning you only need a computer and a problem to solve. Think ai-contest or mlcomp or similar.
Do do interesting data mining you need a computer, a lot of data and a question to answer. If you have an internet connection the amount of data you can get at is only limited by your bandwidth. Think netflix prize, try your hand at collecting and interpreting data from wherever. If you are learning, this is a nice place to start.
As for computer vision: All you need is a computer and images. Depending on the type of problem you find interesting you could do some processing of random webcam images, take all you holiday photo's and try to detect where all your travel companions are in them. If you have a webcam your options are endless.
Lego mindstorms allows you to combine machine learning and computer vision. I'm not sure where the datamining would come in, and you will spend (waste?) time on the robotics/electronics side of things, which you don't list as one of your passions.

Well, I would take a look at the irobot create... well within your budget, and very robust.
Depending on your age, you may not want to be seen with a "lego robot" if you are out of college :-)
Anyway, I buy the creates in batches for my lab. You can link to them with a hard cable(cheap) or put a blue tooth interface on it.
But a webcam on that puppy, hook it up to a multicore machine and you have an awesome working robot for the things you want to explore.
Also, the old roombas had a ttl level serial port (if that did not make sense to you , then skip it). I don't know about the new ones. So, it was possible to control any roomba vacuum from a laptop.
The Number One rule, and I cannot emphasize this enough: Have a reliable platform for experimentation. If you hand build something, just for basic functionality, you will spend all your time on minor issues and not get to the fun stuff.
Anyway. best of luck.

Related

Holiday project goals for undergrads with an FPGA?

It's a student project for vacation research, under-grad, not sure how many of us, there'll probably be 4-6, we're motivated.
My original proposal was to get an FPGA (on an Artix-7 or Z-board) to run a CID camera sensor as a dumb peripheral, do some basic image processing stuff on it (perhaps edge detection and dynamic windowing), and output a bitmap to a PC.
One of the faculty who has about 16 years experience with FPGAs has suggested that for my (and my colleagues) level, this might not be achieveable in a 6-10 week time-frame (we're all pretty much beginners).
We wish to keep the original goal on a more long term basis, but want now to have some other project goals, that would move us towards having the skills and experience (and perhaps some of the IP) for this ultimate goal.
What would some good intermediate project goals be for a group of undergrad beginners with a summer holiday to spend if we ultimately would like to get an FPGA doing cool stuff with a CID camera sensor?
what about distance estimation - using two cameras or more in stereo.

Recognition of an animal in pictures

I am facing a challenging problem. On the courtyard of company I am working is a camera trap which takes a photo of every movement. On some of these pictures there are different kinds of animals (mostly deep gray mice) that cause damages to our cable system. My idea is to use some application that could recognize if there is a gray mouse on the picture or not. Ideally in realtime. So far we have developed a solution that sends alarms for every movement but most of alarms are false. Could you provide me some info about possible ways how to solve the problem?
In technical parlance, what you describe above is often called event detection. I know of no ready-made approach to solve all of this at once, but with a little bit of programming you should be all set even if you don't want to code any computer vision algorithms or some such.
The high-level pipeline would be:
Making sure that your video is of sufficient quality. Gray mice sound kind of tough, plus the pictures are probably taken at night - so you should have sufficient infrared lighting etc. But if a human can make it out whether an alarm is false or true, you should be fine.
Deploying motion detection and taking snapshot images at the time of movements. It seems like you have this part already worked out, great! Detailing your setup could benefit others. You may also need to crop only the area in motion from the image, are you doing that?
Building an archive of images, including your decision of whether they are false or true alarm (labels in machine learning parlance). Try to gather at least a few tens of example images for both cases, and make them representative of real-world variations (do you have the problem during daytime as well? is there snowfall in your region?).
Classifying the images taken from the video stream snapshot to check whether it's a false alarm or contains bad critters eating cables. This sounds tough, but deep learning and machine learning is making advances by leaps; you can either:
deploy your own neural network built in a framework like caffe or Tensorflow (but you will likely need a lot of examples, at least tens of thousands I'd say)
use an image classification API that recognizes general objects, like Clarifai or Imagga - if you are lucky, it will notice that the snapshots show a mouse or a squirrel (do squirrels chew on cables?), but it is likely that on a specialized task like this one, these engines will get pretty confused!
use a custom image classification API service which is typically even more powerful than rolling your own neural network since it can use a lot of tricks to sort out these images even if you give it just a small number of examples for each image category (false / true alarm here); vize.it is a perfect example of that (anyone can contribute more such services?).
The real-time aspect is a bit open-ended, as the neural networks take some time to process an image — you also need to include data transfer etc. when using a public API, but if you roll out your own, you will need to spend a lot of effort to get low latency as the frameworks are by default optimized for throughput (batch prediction). Generally, if you are happy with ~1s latency and have a good internet uplink, you should be fine with any service.
Disclaimer: I'm one of the co-creators of vize.it.
How about getting a cat?
Also, you could train your own custom classifier using the IBM Watson Visual Recognition service. (demo: https://visual-recognition-demo.mybluemix.net/train ) It's free to try and you just need to supply example images for the different categories you want to identify. Overall, Petr's answer is excellent.

Audio Subtitle Transcription - C++

I'm on a project that among other video related tasks should eventually be capable of extracting the audio of a video and apply some kind of speech recognition to it and get a transcribed text of what's said on the video. Ideally it should output some kind of subtitle format so that the text is linked to a certain point on the video.
I was thinking of using the Microsoft Speech API (aka SAPI). But from what I could see it is rather difficult to use. The very few examples that I found for speech recognition (most are for Text-To-Speech which mush easier) didn't perform very well (they don't recognize a thing). For example this one: http://msdn.microsoft.com/en-us/library/ms717071%28v=vs.85%29.aspx
Some examples use something called grammar files that are supposed to define the words that the recognizer is waiting for but since I haven't trained the Windows Speech Recognition thoroughly I think that might be adulterating the results.
So my question is... what's the best tool for something like this? Could you provide both paid and free options? Well the best "free" (as it comes with Windows) option I believe it's SAPI, all the rest should be paid but if they are really good it might be worth it. Also if you have any good tutorials for using SAPI (or other API) on a context similar to this it would be great.
On the whole this is a big ask!
The issue with any speech recognition system is that it functions best after training. It needs context (what words to expect) and some kind of audio benchmark (what does each voice sound like). This might be possible in some cases, such as a TV series if you wanted to churn through hours of speech -separated for each character- to train it. There's a lot of work there though. For something like a film there's probably no hope of training a recogniser unless you can get hold of the actors.
Most film and TV production companies just hire media companies to transcribe the subtitles based on either direct transcription using a human operator, or converting the script. The fact that they still need humans in the loop for these huge operations suggests that automated systems just aren't up to it yet.
In video you have a plethora of things that make you life difficult, pretty much spanning huge swathes of current speech technology research:
-> Multiple speakers -> "Speaker Identification" (can you tell characters apart? Also, subtitles normally have different coloured text for different speakers)
-> Multiple simultaneous speakers -> The "cocktail party problem" - can you separate the two voice components and transcribe both?
-> Background noise -> Can you pick the speech out from any soundtrack/foley/exploding helicopters.
The speech algorithm will need to be extremely robust as different characters can have different gender/accents/emotion. From what I understand of the current state of recognition you might be able to get a single speaker after some training, but asking a single program to nail all of them might be tough!
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There is no "subtitle" format that I'm aware of. I would suggest saving an image of the text using a font like Tiresias Screenfont that's specifically designed for legibility in these circumstances, and use a lookup table to cross-reference images against video timecode (remembering NTSC/PAL/Cinema use different timing formats).
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There's a bunch of proprietary speech recognition systems out there. If you want the best you'll probably want to license a solution off one of the big boys like Nuance. If you want to keep things free the universities of RWTH and CMU have put some solutions together. I have no idea how good they are or how well they might be suited to the problem.
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The only solution I can think of similar to what you're aiming at is the subtitling you can get on news channels here in the UK "Live Closed Captioning". Since it's live, I assume they use some kind of speech recognition system trained to the reader (although it might not be trained, I'm not sure). It's got better over the past few years, but on the whole it's still pretty poor. The biggest thing it seems to struggle with is speed. Dialogue is normally really fast, so live subtitling has the extra issue of getting everything done in time. Live closed captions quite frequently get left behind and have to miss a lot of content out to catch up.
Whether you have to deal with this depends on whether you'll be subtitling "live" video or if you can pre-process it. To deal with all the additional complications above I assume you'll need to pre-process it.
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As much as I hate citing the big W there's a goldmine of useful links here!
Good luck :)
This falls into the category of dictation, which is a very large vocabulary task. Products like Dragon Naturally Speaking are amazingly good and that has a SAPI interface for developers. But it's not so simple of a problem.
Normally a dictation product is meant to be single speaker and the best products adapt automatically to that speaker, thereby improving the underlying acoustic model. They also have sophisticated language modeling which serves to constrain the problem at any given moment by limiting what is known as the perplexity of the vocabulary. That's a fancy way of saying the system is figuring out what you're talking about and therefore what types of words and phrases are likely or not likely to come next.
It would be interesting though to apply a really good dictation system to your recordings and see how well it does. My suggestion for a paid system would be to get Dragon Naturally Speaking from Nuance and get the developer API. I believe that provides a SAPI interface, which has the benefit of allowing you to swap in the Microsoft speech or any other ASR engine that supports SAPI. IBM would be another vendor to look at but I don't think you will do much better than Dragon.
But it won't work well! After all the work of integrating the ASR engine, what you will probably find is that you get a pretty high error rate (maybe half). That would be due to a few major challenges in this task:
1) multiple speakers, which will degrade the acoustic model and adaptation.
2) background music and sound effects.
3) mixed speech - people talking over each other.
4) lack of a good language model for the task.
For 1) if you had a way of separating each actor on a separate track that would be ideal. But there's no reliable way of separating speakers automatically in a way that would be good enough for a speech recognizer. If each speaker were at a distinctly different pitch, you could try pitch detection (some free software out there for that) and separate based on that, but this is a sophisticated and error prone task.) The best thing would be hand editing the speakers apart, but you might as well just manually transcribe the speech at that point! If you could get the actors on separate tracks, you would need to run the ASR using different user profiles.
For music (2) you'd either have to hope for the best or try to filter it out. Speech is more bandlimited than music so you could try a bandpass filter that attenuates everything except the voice band. You would want to experiment with the cutoffs but I would guess 100Hz to 2-3KHz would keep the speech intelligible.
For (3), there's no solution. The ASR engine should return confidence scores so at best I would say if you can tag low scores, you could then go back and manually transcribe those bits of speech.
(4) is a sophisticated task for a speech scientist. Your best bet would be to search for an existing language model made for the topic of the movie. Talk to Nuance or IBM, actually. Maybe they could point you in the right direction.
Hope this helps.

I'm an experienced C++ developer - how can I enter the gaming industry?

I've been working in C++ in embedded environments for a number of years, developing navigation applications. There is a gaming company in my hometown that I like the look of, but I don't have game development experience. You could consider a navigation app as a type of game, depending on who you are running from.
My question is, what steps should I take to enter the industry? Is it a bad idea to enter the industry at this stage (I'm 30)?
Being 30 doesn't really matter, you can enter the games industry at any age assuming you have the drive and ability.
Start reading about gaming topics, and game development websites (gamedev, gamasutra etc.)
Start writing games. Clones of games you like, your own original ideas, tech demos, anything that you can point to and say "I wrote that, and along the way I learned these things, and solved these problems."
If there is a specific area of interest to you, AI, Rendering, Frontend, Tools & Pipelines, Audio, focus on building game/demo/sample projects that challenge you in that area. "Yeah, I've done that" sounds a lot better in an interview than "yeah I've heard of that".
Get to know people in the industry if you can, through online forums, friends of friends, etc... One good contact can do more for your chances than weeks of demo coding or months of sending resumes out. Game companies may have open houses or job fairs.
The "entry level" jobs in game development are likely to be Frontend or Tools. If you've done navigation apps, sounds like that might be a decent fit for you. If that has included more low level work and optimization on embedded platforms, you might also look at Systems roles.
I'd suggest you start trying to write some games in your spare time. Having some demos is always a good start when you go to an interview and it'll give you some insights into what your job is going to be.
Gamedev.net has an excellent set of tutorials to work through to get a grip of a lot of game-coding concepts.
Do they have any job offerings? If so, look at what they ask for in the CV and start educating yourself in those concepts / technologies.
Contacting them and asking if they have any jobs for an excellent software engineer can't hurt either :)
I see you already accepted an answer, but I'll throw in my two cents:
If the company does console (e.g. Xbox360, PS3) or handheld (e.g. DS, iPhone) games, you should definitely emphasize the embedded aspect of your resume. A few anecdotes about how you optimized the memory layout of a class, or sped up some code by taking advantage of an obscure feature of the chipset will show that you can think like a console programmer. Also, if you did any sort of AI for the navigation apps (e.g. A*, Djikstra), it's good to mention that.
A few people recommended writing games - that's not a bad long term plan if you know you want to get into the industry, but I don't think you should let that stop you from applying to this particular company in the meantime. However you should definitely pick up a copy of one of their recent games, play it for a few hours over the weekend, and be able to say what you liked about it.
As for websites, I second the Gamasutra recommendation, along with Kotaku.
Good luck!
"game industry" is a broad question. There are:
AI programming
Graphic programming.
Sound programming.
Tool programming.
Scripting.
Physics programming.
Network programming.
You probably already can deal with #7, #5 and #4.
As for the rest - mostly it is a dealing with some kind of API, plus you need a very good understanding of 3D math (unless you make 2D game, that is).
For 3d math I cannot help you. I picked info in various non-english sources, and most of them aren't available anymore. However, I think this resource might contain info of interest.
For general 3d graphic info you need to study DirectX SDK and NVidia SDKs (both DirectX and OpenGL), plus there are OpenGL books you HAVE to read:
1. Francis s Hill, "Computer Graphics using OpenGL".
2. OpenGL programming guide aka "Red Book"
3. OpenGL shading language (aka "Orange Book")
4. And you might want to take a look at OpenGL reference manucal ("Blue Book")
I'm talking about OpenGL because while it doesn't offer same level of control for hardware resources, it is easier to get started with than DirectX, and available on larger selection of platforms and have a same power as DirectX. Plus GLSL isn't that different from HLSL (except that GLSL doesn't have remnants of assembly shader programming like HLSL), close enough to C++, so it is relatively easy to get started.
One important thing - if you seriously want to deal with 3D, you have to be able to easily imagine 3d operations in your mind. I.e. how to rotate object, scale object, move object, what matrix means, what is reflection vectors, how to cut polygon with planes, how to find intersection of two meshes, etc, and you should have at least basic understanding of more complex thing like boolean operations on polygonal meshes. I have no idea how to develop this skill (it is very close to "mechanical drawing"), but you'll get a lot of difficulties without it.
Just putting "experienced C++ dev" on your CV will probably get you in the door. The (UK at least) games industry is dominated by graduates and inexperienced programmers - the older ones either burn out or get promoted into management.
A lot of games programming is just programming - the skills are entirely transferable. And your navigation software experience probably puts you in for an AI-related role.
If someone with your background applied to me, I'd certainly give them an interview.
Well I started at 16 with (paid) game development. Search for jobs on websites. Make your own low-budget games and then publish them in a way or another.
If you are good people will search for you, otherwise you have to struggle a bit.

An example of an embedded project for a single person

I've been trying to wrap my head around embedded. Since I will be self-taught in this specific niche, I realize it will be harder to get a job in the field, so I'm hoping to add a completed project to my resume to prove to potential employers that I've done it and can do it again for them.
Can someone suggest a project that I can undertake as a single person and actually be able to finish, but at the same time not too simple that it doesn't prove anything? Something reasonable that I can aim for.
If you can substantiate your example with a project you worked on yourself, and mention how many people were involved, and how long it took to finish it, that would also help me gauge the difficulty of projects I see in general and rule out the ones that are probably too big for my capacity. It's very difficult to gauge the amount of work a project needs from my position.
You should take a look at the arduino. To quote their site:
Arduino is an open-source electronics prototyping platform based on flexible, easy-to-use hardware and software. It's intended for artists, designers, hobbyists, and anyone interested in creating interactive objects or environments.
There is a really handy playground listing a bunch of personal projects on the arduino, any one of which might fulfil your need to do some embedded development. You can also trawl around the internet (e.g. instructables) to find many other interesting arduino applications -- I particularly like the one building a fancy control system for an espresso machine, and, of course, there is the mandatory fart detecting chair that tweets its findings.
Being an arduino experimenter myself, I can attest to the simplicity and power of this device -- and the great fun you will have playing with it. If you want to get started quickly, I can recommend buying the starter kit from the very helpful people at oomlout.
Are you looking specifically at embedded software development, or are you interested in circuit board design as well?
If it's just software, then I would suggest getting hold of an ARM development board (Possibly the Philips LPC range - sparkfun have some nice ones) that you can program via a bootloader over usb and start hacking. Get one with a display and an ethernet port and you can build up to making some sort of network attached sensor (temperature, water level, object counter, etc). Start out little (turn on a LED from a button) and work your way up.
If you're also into the electronics side of things, I'd suggest something like an MP3 (or WAV) player and maybe stick to the AVR or PIC 8bit microcontrollers (AVR is used on the Arduino) as these are a little easier to deal with than ARM. Here you could start with a usb powered device that streams wav files from a PC serial port out to a pair of headphones, and build up to a battery powered board, feeding data to an MP3 decoder IC from an SD card.
Some things you may want to learn & demonstrate:
Understands the bounds of working with limited resources, including memory management (dynamic and/or static); resource management (locks, semaphores, mutex); multiple tasks (interrupts); and appropriate data structures
Ability to interface with other devices/ICs over various interconnects (analog & digital IO, serial bus (RS232, I2C, SPI))
Ability to sanely structure a program and segment the various modules without producing 'spaghetti' code
Ability to use source and integrate 3rd party libraries where appropriate (think FAT filesystem, or TCP/IP stack)
Misc Tips:
read and understand the datasheets (yes all of them)
code and test on the desktop where possible, but understand that there are differences and bugs will still creep through (this is where it helps to be using a tool-chain that is common with the desktop - GCC is good, but the tools are generally CLI)
use assert a lot - you can flash the line number of a failed assert using a single LED - this is invaluable
Most of all have fun - it still makes me smile when you first get a new component working (display, motor, sensor). Embedded makes the world go round :)