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by PaulBuxton
Tue Oct 02, 2012 1:52 pm
Forum: Camera board
Topic: Autofocus
Replies: 10
Views: 15405

Re: Autofocus

If you can precisely describe how the image was blurred you can undo the blurring. Standard blurring is just a multiplication in Fourrier space (FFT(burred image) = FFT (original image) * blur_function ) . So just divide by the blurring function and you've "undone" the blurring!. Not quite, the (FF...
by PaulBuxton
Mon Sep 10, 2012 1:24 pm
Forum: Camera board
Topic: Autofocus
Replies: 10
Views: 15405

Re: Autofocus

... and the results look like witchcraft. It probably is witchcraft As napalm says, You can't really recover the lost information from a blurred image. But if it's not really lost, just reduced drastically in amplitude (which most blurring mechanisms do) then you can recover it. But if there's nois...
by PaulBuxton
Mon Sep 10, 2012 8:07 am
Forum: Camera board
Topic: Autofocus
Replies: 10
Views: 15405

Re: Autofocus

IYou can't really recover the lost information from a blurred image. If you can precisely describe how the image was blurred you can undo the blurring. http://www.mathworks.co.uk/products/demos/image/ipexblind/ipexblind.html I have played around with doing this on a GPU and the results look like wi...
by PaulBuxton
Thu Sep 06, 2012 2:31 pm
Forum: Camera board
Topic: Autofocus
Replies: 10
Views: 15405

Re: Autofocus

Probably not. an EDOF camera is designed such that images are blurred the same regardless of the distance of the object from the camera. The image is then deblurred in the ISP based on knowledge of the properties of the lens system. If you stick another lens on the front of this you will probably sc...
by PaulBuxton
Thu Aug 30, 2012 12:50 pm
Forum: C/C++
Topic: Motion detection and servo response
Replies: 2
Views: 2605

Re: Motion detection and servo response

How are you detecting movement at the moment? What I would probably do is to use OpenCV to detect/track the motion, it has a number of ways of detecting/tracking objects dependant on the type of thing you want to track. You would probably end up with a bounding box for the object being tracked which...
by PaulBuxton
Thu Aug 30, 2012 9:00 am
Forum: C/C++
Topic: Debugging on a Pi
Replies: 18
Views: 24831

Re: Debugging on a Pi

I would agree with Matt, if the tools are available then learn to use them, gdb used well can be very powerful. In addition you can learn to code things in such a way that if your program fails, it should be able to give you a clue why. Testing assumptions about your code (e.g. checking parameters t...
by PaulBuxton
Thu Aug 30, 2012 8:42 am
Forum: General programming discussion
Topic: Where to start
Replies: 4
Views: 1892

Re: Where to start

I would recommend playing around with a linux distribution of some sort before worrying about the Pi side of things. Either try a Live CD as has already been mentioned, or a virtual machine. I prefer a virtual machine as it lets you install extra software packages more easily. What OS have you typic...
by PaulBuxton
Wed Aug 29, 2012 10:52 am
Forum: Beginners
Topic: MPEG-2 Licence Available - What does this mean for me?
Replies: 3
Views: 1850

Re: MPEG-2 Licence Available - What does this mean for me?

So The MPEG2 license means that you will be able to use the Pi hardware to accelerate MPEG2 decode. So streams that have been captured already and stored on a storage medium (like DVD's) can benefit from this so long as you use software that can access the hardware acceleration. For watching freevie...
by PaulBuxton
Fri Aug 17, 2012 2:22 pm
Forum: Staffroom, classroom and projects
Topic: Slashdot: How Many of You Actually Use Math?
Replies: 7
Views: 1781

Re: Slashdot: How Many of You Actually Use Math?

Maths involved in my everyday work 1) Matrix maths involved in colour space conversion 2) DCT based transforms 3) Filtering operations Plenty of incidental maths as well. I may not have to sit down and type the maths out every day, but I have to understand what it is happening at a fairly fundamenta...
by PaulBuxton
Thu Aug 16, 2012 10:27 am
Forum: Camera board
Topic: Camera module! (And a picture of JamesH)
Replies: 431
Views: 161912

Re: Camera module! (And a picture of JamesH)

Hmm, a V4L driver would be compatible with a wider array of existing software/libraries.....

Paul
by PaulBuxton
Wed Aug 15, 2012 2:34 pm
Forum: General programming discussion
Topic: Potentially useful things to program
Replies: 8
Views: 3603

Re: Potentially useful things to program

Lots of interesting challenges on Project Euler and the Sphere Online Judge (SPOJ) . Had a quick look at the Project Euler site, looks interesting, although I couldn't tell if they have any way of determining how good your solution is, which would make it more interesting. For example one of the fi...
by PaulBuxton
Tue Aug 14, 2012 9:01 am
Forum: General programming discussion
Topic: Potentially useful things to program
Replies: 8
Views: 3603

Re: Potentially useful things to program

Some general computer science type algorithms are useful Searching and sorting algorithms. Trees and graphs Calculate Pi (multiple ways of doing it, perhaps most intuitive/fun way is to plot random points within a square of size NxN and then work out the ratio of points that fall within the circle w...
by PaulBuxton
Fri Aug 10, 2012 8:18 am
Forum: General programming discussion
Topic: Help with an machine vision project!!!
Replies: 7
Views: 2582

Re: Help with an machine vision project!!!

So OpenCV can certainly help with object tracking, and it also has stuff to cope with stereo imaging for depth perception.
Something else you might want to look into is ROS http://www.ros.org/wiki/ I think I saw a comment on the forums here with some guys getting ROS up and running on the Pi.

Paul.
by PaulBuxton
Thu Aug 09, 2012 11:34 am
Forum: General programming discussion
Topic: Help with an machine vision project!!!
Replies: 7
Views: 2582

Re: Help with an machine vision project!!!

I would suggest the first step is understanding what you are actually going to try and do. Do you want the Pi to fly the copter for you using the camera, or are you going to fly the copter and have the Pi track interesting things etc? Just getting the Pi to fly the copter will be a large chunk of wo...
by PaulBuxton
Thu Aug 02, 2012 9:26 pm
Forum: C/C++
Topic: My Pi does not find libusb.h
Replies: 12
Views: 42137

Re: My Pi does not find libusb.h

I think that you need to specify the include path so that the compiler knows where to find the header file, and then tell the linker to include the libusb library. so adding something like -I/usr/include/libusb-1.0/ -lusb to your gcc compile options should sort you out. (note the way that linux/gcc ...
by PaulBuxton
Thu Jul 26, 2012 2:10 pm
Forum: General programming discussion
Topic: Options for development environment
Replies: 12
Views: 15951

Re: Options for development environment

Sorry if this is a dumb question, but I've heard of Eclipse but never used it. Does this mean that I can install Eclipse on WinXP, install your compilers wherever Eclipse expects them, install "the make tool" (where do I get that?), and then I'd be able to run this from WinXP to do my development w...
by PaulBuxton
Tue Jul 10, 2012 8:45 am
Forum: Camera board
Topic: HDR camera project
Replies: 5
Views: 6791

Re: HDR camera project

Ah, that makes sense.
Sounds like you have it well thought out. Good luck with the project!

Paul
by PaulBuxton
Mon Jul 09, 2012 3:04 pm
Forum: Camera board
Topic: HDR camera project
Replies: 5
Views: 6791

Re: HDR camera project

Is there a specific reason for using the RPi for your project? Whilst it is great fun, and cheap. It may be easier to go for a standard PC running linux with a webcam attached. From the sound of things you are doing a software project, in which case it would make sense to keep the hardware choice fl...
by PaulBuxton
Tue Jul 03, 2012 9:43 am
Forum: C/C++
Topic: How to add a graphical interface to C program
Replies: 5
Views: 3640

Re: How to add a graphical interface to C program

I have had a brief play with (and been quite impressed with) QT. It is C++ but I think anything that you use for interfaces will be as things like that are fairly object oriented. It is cross platform (so you can develop and test on a Windows/Mac machine before porting to the Pi). http://qt-project....
by PaulBuxton
Tue Jul 03, 2012 9:35 am
Forum: Linux Kernel
Topic: libusb not writing to buffer in isochronous mode
Replies: 12
Views: 8475

Re: libusb not writing to buffer in isochronous mode

Well I am afraid that pretty much exhausts my knowledge of libusb. :( I would suggest perhaps initialising the buffer with something other than 0 just to check if it is is being updated with 0 rather than simply not being updated. Other than that perhaps add some debug to the libusb library, and/or ...
by PaulBuxton
Mon Jul 02, 2012 11:43 am
Forum: Linux Kernel
Topic: libusb not writing to buffer in isochronous mode
Replies: 12
Views: 8475

Re: libusb not writing to buffer in isochronous mode

Have you tried turning on Debug messages with
libusb_set_debug ?

Are you using the same version of the library on PC and RPi? If not might be worth checking the differences.

Paul
by PaulBuxton
Mon Jun 25, 2012 5:05 pm
Forum: C/C++
Topic: openframeworks
Replies: 2
Views: 2453

Re: openframeworks

So, just to give some more details in case you end up having to go this route. I installed scratchbox2. cd into the folder containing my root file system (copied from the sd card) sb2-init -c qemu-arm raspberry /home/paul/rpi/tools/arm-bcm2708/linux-x86/bin/arm-bcm2708-linux-gnueabi-gcc Which will c...
by PaulBuxton
Mon Jun 25, 2012 12:43 pm
Forum: C/C++
Topic: openframeworks
Replies: 2
Views: 2453

Re: openframeworks

Hi, What you are basically trying to do is to cross compile a library (and test applications). Which is doable although can be a bit tricky (as I have been finding myself). My first suggestion would be to look at http://russelldavis.org/2012/01/27/setting-up-a-vm-for-raspberry-pi-development-using-v...
by PaulBuxton
Thu Jun 21, 2012 12:10 pm
Forum: Debian
Topic: Debian Wheezy Wifi adapter support
Replies: 6
Views: 4618

Re: Debian Wheezy Wifi adapter support

Looks like I must have made some faux pas in asking this since this post is pretty much being ignored. Anyway, I've gone with the Edimax EW-7811UN in the end as I have found several guides that mention it. I can confirm I have that adapter working using the automatic installation script mentioned i...
by PaulBuxton
Wed Jun 20, 2012 10:49 pm
Forum: Camera board
Topic: Drivers?
Replies: 13
Views: 10830

Re: Drivers?

Pretty much the feature list I was expecting, I look forward to being able to get a camera with this properly setup. Burngate Both noise reduction and sharpening can ( and should) be aware of the fact that the sensors have a Bayer pattern(I.e. need demosaicing), which can be taken into account for b...

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