I want build a fingerprint control access in Java. I have a device to get a thresholded fingerprint image and I do some image processing, but I get a high rate of error.
My question is, exists a fingerprint sensor device with its own characterization system?. I mean, the device takes a fingerprint and its output is a serial number or an characteristics vector, not a image, I dont want to do a image processing system to do this.
With this data characteristics is very easy to get a degree of similarity between fingerprints and decrease my rate of error, but I dont know if in the market exist that kind of device.
I appreciate a lot if you guys help me to choose what to do, buy a magic fingerprint device or continue with my image processing system.
Thanks a lot.
To match fingerprints, you have to compare minutiae.
Please read this: https://en.wikipedia.org/wiki/Fingerprint_recognition
Here some fingerprints scanner with SDK to enroll, capture and check fingerprint:
http://www.morpho.com/en/biometric-terminals/oem-modules/fingerprint-modules/morphosmart-cbm-series
http://www.crossmatch.com/authentication-hardware/
Or you could use MegaMatch SDK, this SDK provides methods to enroll, capture and check on a lot of fingerprint scanners.
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i have to build a project that uses an FPGA with the software Modelsim. the project is a range finder or measuring tape.
I already know the basics of modelsim, but I've never done anything like this. the sensor that i am using is an Infra red proximity sensor. https://www.sparkfun.com/products/242 . I am aware that i will need to use an Analog to digital converter, in order for the fpga to recognize the sensor. this sensor also has to rely on is output voltage to determine the distance. the distance will then be displayed on an LCD screen. The problem i have is that i'm not sure where to start.
so if anyone can give any advice, a sample code for this problem or anything it would be appreciated.
Each of these subjects can be a large subject of their own. As it is, you should narrow down your question into something more specific -- where are you stuck? That said, here are some thoughts to help you narrow your questions.
You have correctly identified what you need to do: utilize an A/D converter, and display range (distance) on an LCD screen.
Let's break what you need to do in a little more details.
You need to interface with the A/D converter. For example, what pins are the data pins attached to on your FPGA? How do you need to clock the A/D? Basically, you need to figure out how to get digital samples into your FPGA logic.
You need to convert your digital samples from a voltage to a range. A lookup table is an excellent way to do this. The input to the lookup table will be (digital) voltage, the output will be range.
You need to learn how to interface with an LCD screen/panel. At minimum, you are going to have to learn how to draw/redraw a few characters on the screen representing the range.
Once you have these 3 components, you need to tie them together. The A/D interface in the FPGA will periodically generate voltage values, the lookup table will convert voltages to range, and then you will display the range value on your LCD.
Is it possible by using the Zbar API, that one can check if the image consists of barcode or not?
This is as a backup measure, so that if the application is unable to get barcode value, let it check if it might contain a barcode, if so user can later manually verify it.
I have explored quite a bit but with no major success. If not ZBar, any other open source library that can do it well?
Thanks
What you need is a detector, i.e. the ability to locate the barcode (if any), and thus just return yes or no according to the detection result.
IMHO Zbar does not provide a versatile enough API to do so since it exposes a high-level scanner interface (zbar_scan_image) that combines detection & decoding on one hand, and a pure decoder interface on the other hand.
You should definitely refer to this paper: Robust 1D Barcode Recognition on Mobile Devices. It contains an entire section related to the detection step including pseudo-algorithms [1] - see 4. Locating the barcode. But there is no ready-to-use open source library: you would have to implement your own detector based on the described techniques.
At last, more pragmatic/simple techniques may be used depending on the kind of input images you plan to work with (is there any rotation? blur? is it about processing images or the video stream in real-time?).
[1] In addition I would say that it's a good idea to use a different kind of algorithm within this fallback step than the one used within the first step.
i need to measure the time between 2 points. I can not use a simple watch because i have no free hands for this. (mountainbike - downhill)
My first idea was to set two GPS points and measure the the time between those points, but I think it will be to inaccurate.
my second idea was to set one bluetooth device to each Point and just measure the distance from me to the bluetooth device , check the shortest distance and save the time.
But than I realized that I would need 3 bluetooth devices to make a distance calculation, which is kinda annoying.
Any idea how i can measure the time between two points with an accuarcy <1sec ?
I want to control this via smartphone.
edit:
Okay i have another idea. Maybe i could set one bluetooth device to each point. I set the signal strenth to <=1m. Than i could easily start and stop the time until i receive the bluetooth signal on my android.
Do you think this would be the best approach ?
It seems you're trying to take total and split times for a course. Definitively, forget of using bluetooth for other things that are not constant transmissions, with slow connection time... (I speak from experience). Of course you want to do it in the cheap, because there already professional solutions for that (e.g.).
From my point of view, if you want something accurate and been able to integrate it with you phone, you'll need the following:
DIY photocell sensors. Maybe involving simple chip (e.g. msp430), phototransistor-diode pair, cheap 433mhz transmitter and batteries.
DIY 433mhz receiver for your phone. There already many boards that supports android open accessory library, (e.g. 49$ from sparkfun), so you only have to connect it to a 433mhz receiver and to your phone.
Custom code programming in your android phone. To be able to receive the signals from the split signal senders and keep track of all times.
It seems to be a pretty decent project for under $250-200(if you self made it :P).
One possible solution that does not require any special hardware would be to use a smartphone at the finish line. You would only need an extra smartphone (SP) with net connection, and some software.
SP sends the start signal to your phone. You start when you hear the signal.
SP uses its camera to detect when you reach the finish line.
SP calculates the time between start and stop and displays it, and possibly sends the info to your phone, too.
Maybe you could even record a video with time stamps.
(Of course, the low cost solution would be to let one of the guys to use a stopwatch at the finish line.)
Good evening all.
I'm just trying to collate some ideas really and was wondering if I could pick some brains.
I'd like to develop an app that relies upon measuring distance reasonably accurately. So for example, I have a central point, I want to be able to detect whether the phone is within a radius of a meter.
How could I achieve this?
The points would be static but I don't think GPS would be accurate enough to rely on this solely.
I'm definitely not a hardware chap but is there a way of combining GPS and some other sort of transmitter to ensure accuracy?
Any help or suggests greatly appreciated.
One meter accuracy? It's probably not going to happen with any phone hardware out there - definitely not with any Windows Phone. GPS isn't accurace enough without a differential beacon, and phones don't have the hardware to receive that (and I doubt you have a differential transmitter either).
The location service on the phone (assuming high accuracy is selected) combines data from GPS, cell towers and WiFi hot spots to provide a location.
There is no way to include the use of other sensors to improve this data.
You also won't be able to get the level of accuracy you're after from the phone. It's just not designed for the purpose you describe.
hey guys,
i'm working on a concept for university. i wonder what's the easiest and best way to measure certain vibration in a room. imagine a room full o people dancing. is there any affordable device i can put on the floor that sends data to my computer so i can read out vibration values or use vibration as data?
thank you for your help
I would guess that a microphone, as Pointy suggested, would work, but if you're on a near-zero budget, find an old speaker and bolt it face-down to the floor. Connect the wires to a 1/8" phono plug and plug it into the microphone-in jack on your sound card. Record the vibration data using Audacity. The floor's vibration will flex the speaker cone and generate small amounts of electricity, which the sound card input will see. If you put a foam-lined box over the top (actually back) of the speaker you'll minimize the effect of sound waves from the air on the speaker cone.
There is specific noise monitoring equipment which could serve that purpose, depending on how accurate the information you are monitoring needs to be.
I used to operate sound monitoring equipment as part of a rotating equipment inspection program when I was in the Navy. Basically it was a set of transducers you mounted to the equipment you wanted to monitor, and a proprietary box for recording and analyzing the results. I'm sure you could easily replicate that functionality with a PC.
Do a search for "Vibration Monitoring Equipment" or "Condition Monitoring" and see what turns up. If you are at a University with an engineering department I would imagine the ME's would have something like what you're looking for.