Brij Raj Singh

When Mac app store says Lion Installed, but its not installed

2012-01-07T11:59:00.000+05:30

Recently by mistake, i ended up corrupting the lion installation, and now when I opened the lion it said installed, but it wasn't installed.
Looked at a lot of places some said , "click alt-option button while launching app store and everything will be fine" while it didn't worked for me.

The catch is to remove the application "Install Lion" from your applications folder first, you can search it from spotlight, and then launch the app store {now you may use alt-option button, just keep it pressed while you launch the app store, and voila! you will be able to download lion now.

One more thing, lot of people were worried on forums, that the before you install the button says "Buy" but actually if you have bought it once, you won't need to pay for every time you download, so feel free to download it as many times as you want it to.

Imified API - using C#

2011-12-13T11:28:00.001+05:30

Recently I had to do an imified bot implementation for one of our products, and it was damn cumbersome to get the api's working, although the PHP code just works fine as they provide on the website www.imified.com

I first tried trapping the php code's httprequest in the httpanalyzer and fiddler, but as it was php code doing a httpPOST, i couldn't just get it, So i created my own handler, changed the url to that handler and dumped the HTTPRequest; i found that the authorization has to be sent in HEADER, and not only that, it also has to be base64 encoded.

update - This API was recently made live at github as Imified C# Library

Here's how i implemented one of the functions of the API.

Coding standards

2011-04-29T13:44:00.000+05:30

Coding standards and guidelines

View more presentations from brijraj_singh.

Delete Duplicate record but keep the original record

2011-03-15T16:30:00.000+05:30

Straight forward situation when you have the duplicates in a table, but you want to keep just one instance of a row, and delete others

lets say the base table is like this

id	name	sex
1	mac	M
1	mac	F
2	manu	F
2	manu	F
2	manu	F
3	chester	M
3	chester	M

Lets call it SOURCE table, lets put a relative instance count by using row count

go
;with cte as
(
Select id, row_number() over(partition by id order by id) As Rownumber
,Row_number() over (order by id) As R2
,(select max(id) from SOURCE) AS MaxId
from SOURCE
)

--now delete the records for which the instance count is greater than 1

Delete cte
where rownumber > 1

that's it.....

Several variances of same may help you, provide new id's to duplicates, and do a lot of other kind of stuff with duplicate data, do as you will................

Courtesy - Ahmad osama @ http:\\sqlcookbook.wordpress.com

Get Key value pairs out of json – The REGEX way

2011-02-01T20:42:00.003+05:30

Recently got challenged to get the Key value pairs out of a json encoded object….

Here’s how my Regex looks…

Regex regex = new Regex("\"(?<Key>[\\w]+)\":\"?(?<Value>([\\s\\w\\d\\.\\\\\\-/:_]+(,[" + ",\\s\\w\\d\\.\\\\\\-/:_]+)?)+)\"?", RegexOptions.Multiline | RegexOptions.Compiled);

// Capture all Matches in the InputText

MatchCollection ms = regex.Matches(_value);

foreach (Match item in ms)

{

//get key and value per match

}

Setting Privacy options in Status Update via Facebook toolkit

2011-01-31T18:36:00.000+05:30

Recently I was working over the status updates via facebook toolkit http://facebooktoolkit.codeplex.com/, which works like a charm no doubt about that.

But one of the requirements I had this time, was to allow the facebook application to set the status updates, but with a privacy level of SELF.

I have read the Facebook publish stream API in detail, and I was quite sure that there must be an option there in the facebook toolkit, to use the privacy levels as specified in facebook documentation here http://developers.facebook.com/docs/reference/rest/stream.publish/

Apparently I couldn’t find any option with the Facebook toolkit to use the privacy options.

How hard could it to be extend the toolkit to start doing the privacy thing?

Answer – not at all.

The facebook Rest based api expect the applications to send the privacy levels as a json encoded object – as per documentation ---

privacy

object

A JSON-encoded object that defines the privacy setting for a post, video, or album. It contains the following fields.

· value (string): The privacy value for the object, specify one of EVERYONE, CUSTOM, ALL_FRIENDS, NETWORKS_FRIENDS, FRIENDS_OF_FRIENDS, SELF.

· friends (string): For CUSTOM settings, this indicates which users can see the object. Can be one of EVERYONE, NETWORKS_FRIENDS (when the object can be seen by networks and friends), FRIENDS_OF_FRIENDS, ALL_FRIENDS, SOME_FRIENDS, SELF, or NO_FRIENDS (when the object can be seen by a network only).

· networks (string): For CUSTOM settings, specify a comma-separated list of network IDs that can see the object, or 1 for all of a user's networks.

· allow (string): When friends is set to SOME_FRIENDS, specify a comma-separated list of user IDs and friend list IDs that ''can'' see the post.

· deny (string): When friends is set to SOME_FRIENDS, specify a comma-separated list of user IDs and friend list IDs that ''cannot'' see the post.

Only the user can specify the privacy settings for the post. You can create an interface that lets the user specify the privacy setting. For CUSTOM settings, use friends.getand friends.getLists to get the user's friends and friend lists to populate the interface, then pass along the selections to the privacy object.

Note: This privacy setting only applies to posts to the current or specified user's own Wall; Facebook ignores this setting for targeted Wall posts (when the user is writing on the Wall of a friend, Page, event, group connected to the user). Consistent with behavior on Facebook, all targeted posts are viewable by anyone who can see the target's Wall.

Privacy Policy: Any non-default privacy setting must be intentionally chosen by the user. You may not set a custom privacy setting unless the user has proactively specified that they want this non-default setting.

I created an overloaded function of public string Publish(string message,string privacy) in Stream.cs of C# project of facebook toolkit’s Facebook base project.

Here’s how it looks

STREAM.cs

public string Publish(string message,string privacy)

{

return Publish(message, null, null, null, 0, false, null, null,privacy);

}

Then I wrote an overload of the private publish function in the same class stream.cs, again with the privacy string in it, here’s how that function looks

Look for the additional parameter – colored as YELLOW in the below function.

STREAM.cs

/// <summary>

/// For the Privacy based publishing

/// like "{\"value\":\"SELF\"}"

/// </summary>

/// <param name="message"></param>

/// <param name="attachment"></param>

/// <param name="action_links"></param>

/// <param name="target_id"></param>

/// <param name="uid"></param>

/// <param name="isAsync"></param>

/// <param name="callback"></param>

/// <param name="state"></param>

/// <param name="privacy">Privacy like "{\"value\":\"SELF\"}"</param>

/// <returns></returns>

private string Publish(string message, attachment attachment, IList<action_link> action_links, string target_id, long uid, bool isAsync, PublishCallback callback, Object state,string privacy)

{

var parameterList = new Dictionary<string, string> { { "method", "facebook.stream.publish" } };

Utilities.AddOptionalParameter(parameterList, "message", message);

if (attachment != null)

{

var mediaList = new List<string>();

var prop = new Dictionary<string, string>();

if (attachment.properties != null)

{

foreach (var item in attachment.properties)

{

prop.Add(item.name, item.value.ToString());

}

if (attachment.media != null)

{

foreach (var item in attachment.media)

{

var media = new Dictionary<string, string>{

{"type", item.type.ToString()}

};

if (item.type == attachment_media_type.image)

{

var image = item as attachment_media_image;

media.Add("src", image.src);

media.Add("href", image.href);

}

else if (item.type == attachment_media_type.flash)

{

var flash = item as attachment_media_flash;

media.Add("swfsrc", flash.swfsrc);

media.Add("imgsrc", flash.imgsrc);

media.Add("width", flash.width.ToString());

media.Add("height", flash.height.ToString());

media.Add("expanded_width", flash.expanded_width.ToString());

media.Add("expanded_height", flash.expanded_height.ToString());

}

else if (item.type == attachment_media_type.mp3)

{

var mp3 = item as attachment_media_mp3;

media.Add("src", mp3.src);

media.Add("title", mp3.title);

media.Add("artist", mp3.artist);

media.Add("album", mp3.album);

}

else

{

var video = item as attachment_media_video;

media.Add("video_src", video.video_src);

media.Add("preview_img", video.preview_img);

media.Add("video_link", video.video_link);

media.Add("video_title", video.video_title);

}

mediaList.Add(JSONHelper.ConvertToJSONAssociativeArray(media));

}

var dict = new Dictionary<string, string>{

{"name", attachment.name},

{"href", attachment.href},

{"caption", attachment.caption},

{"description", attachment.description},

{"properties", JSONHelper.ConvertToJSONAssociativeArray(prop)},

{"media", JSONHelper.ConvertToJSONArray(mediaList)},

{"latitude", attachment.latitude},

{"longitude", attachment.longitude}

};

Utilities.AddOptionalParameter(parameterList, "attachment", JSONHelper.ConvertToJSONAssociativeArray(dict));

}

if (action_links != null)

{

var list = new List<string>();

foreach (var item in action_links)

{

var dict = new Dictionary<string, string>{

{"text", item.text},

{"href", item.href}

};

list.Add(JSONHelper.ConvertToJSONAssociativeArray(dict));

}

Utilities.AddJSONArray(parameterList, "action_links", list);

}

Utilities.AddOptionalParameter(parameterList, "target_id", target_id);

Utilities.AddOptionalParameter(parameterList, "uid", uid);

Utilities.AddOptionalParameter(parameterList, "privacy",privacy);

if (isAsync)

{

SendRequestAsync<stream_publish_response, string>(parameterList, uid <= 0, new FacebookCallCompleted<string>(callback), state);

return null;

}

var response = SendRequest<stream_publish_response>(parameterList, uid <= 0);

return response == null ? null : response.TypedValue;

}

It’s that simple, at the upper level, I asked my clients to send me the privacy as an object, and I convert it into an encoded json string, this is something that I can’t share due to copyright issues.

Product Service down in holidays, a developer’s nightmare

2010-12-23T17:34:00.002+05:30

Guess! Everybody knows now, Skype is DOWN ! since past 18 hrs. …. The businesses are affected, we couldn't make it to our daily calls, today we realized that the small world we experience everyday because of services like SKYPE is actually a big world.

Seriously, my blessings go to the developer's at skype, I hope they could fix the issue by this night, or in next few hours, or their holiday's may be ruined.

https://twitter.com/Skype/status/17641862433083392#

Update : - YES ! it's working again, coming back to NORMAL.
Ever wondered what kind of hell the dev's must've been through ?

More Old Posts

2010-12-17T13:31:00.001+05:30

16-09-2006

India momentum session at Taj ambassador

I delivered a session (2 hrs.) yesterday at Taj ambassador hotel, for the India Momentum Program.

The Program targets the enterprise customers, and is trying to penetrate into the enterprisem for letting them know about the capabilities and the functionailites that windows vista, and office 2007 offers.

I was accompanied by Dhaval chandra (Our Business development manager), and Mr. Tarun Anand (My Boss), and Mr. Govind Shekharan (Tech. consultant at tpf).

Tarun Sir, and Govind delivered a session on office 2007, and i delivered the windows Vista part.

alas, My Vista just couldn't get connected to the Projector, and i thought that i might not be able to show the demos (especially the CRIS demo), but once everybody seem toget ready for a personal show of the demos, i just swept them off their feets......i promise i had to find a way out for these logistics problems.

I see a lot of people are worried about the Business Desktop deployment, i'll surely go through it once i have some time from the cRIS thing.

Apart i am starting the VistaEvangelism.Com very soon....I am sorry i couldn't go to the meeting today, as i am frail...

PS - they made a video for my presentation, i'll give a link when i have it with me.

05-09-2006

Dad Got Retired

My Dad (Mr. V.P Singh) got retired from Kendriya Bhandar ( A Co-operative dept. estd. by Govt. Of India in 1960's), on dated 31st Of August.

I took an off from work to accompany him on his last visit to the office.

we reached there at about 2 PM, everybody was there, all the old time frnds,his boss,and relatives as well. I was wondering my Dad will really feel very disturbed, but he was indeed feeling good about all this....he only talked with me once during whole day and said "watch this all with your whole concentration, we should feel good when we are getting love from people no matter at what cost....if it's my Retirement that could bring my loved ones at one place, i should go throught it gracefully. Some day you are going to need me, and i was preparing for it, now it's the time that your businesses need me, and i am available to you all".

I am going to count his achievements with us and his dept.

1. He married a good Lady "My MOM"

2. He took care of his DAD very well, though we couldn't share much time together "He died in 1985".

3. He was the only employee ever to join KB directly as Incharge of the Store.

4. He saved KB from getting dissolved, talked with the then President of India Mr. Gyani Jail singh, and convinced him that the dept. would not only take care of its own, but will also give the share from profit as well.
5. He was the first union leader, who pushed the KB officials to arrange the clothes for Junior officers 'They still get one suit length every year'.

6. He initiated a new section "stationary and computers" and made the business of 100 Cr. in one year, which was alone equal to the total income of KB, got appreciated by Govt. Of India for his management capabilities.

7. He's the one for whom people at KB think that "you can send him anywhere, he manges so well that even a dull store with the sale of Rs. 15 thousand Per month can jump to 60 th. Per day".

I Love you DAD, and I promise i'll always obey and take good care of you and my mom.

Thanks for everything

05-08-2006

Webcast session at Microsoft

Hi Friends,

Last week was hectic, as well exciting, i was suppose to deliver some 5 webcasts, "All about WPF" at Microsoft, With Tarun Sir, and know what, he just couldn't turn up for anyone of them, so i was having a chance to go forward and prove my skills...

The details, and On demand webcast is available at http://www.microsoft.com/india/webcasts/ondemand.aspx

I'll improve this post later, with ppt's and code demo links...but this is just like keeping a log.....

Chilllllllliiiiiiinnnnnnnggggg.....

10-07-2006

Vista Beta2 installed, with AERO effects

Today morning Boss delivered me the Vista Beta2 DVD, and asked me to get my hands dirty with this, i was struggling with Vista March CTP since 3-4 months, and was never been able to get the AERO installed, not even on my new Lenovo Laptop, we invested a lot on this laptop.

It'a a cool machine (vista rates is No. 1), Lenovo 3000 N 100, with 1 GB RAM, and intel Centrino Duo processor, I tried a lot of hacks but i just cud never crack it...

Today everything just went fine.... The Voyage Milestones

1. I already had Vista Over Vista, so deleting the windows.old dir. was oooooof! so i just found a hack...

restart Vista
at the boot screen hit the <f8> key
boot into "safe mode with command prompt"
rename windows.old to windows.old1

use the following command to delete the folder and it's contents

del windows.old1\*.* /F /S /Q

/F : force delete on read-only files
/S : include subfolders
/Q : suppress confirmation prompts

2. Started installation of Vista.

3. when Vista is installed, go to Control Panel -> System, and try updating the Graphic Driver, Select "Let me browse my cmputer", and then select "Let me choose from the drivers" remove the check from "Show compatible", and select "Lakeport drivers" from Intel driver's list.

restart the system.

Then when sys. is restarted go to themes, and change the theme to AERO.....

Who aaaaaaaaaaaaaaaaaa ooooooooowwwwwww

i am attaching the pics also

05-07-2006

Windows Vista Pres. at Vertex, Gurgaon

we presented at Vertex technologies, gurgaon...

This time, i just didn't used the ppt, and we (me, and Tarun) talked with demos only, all in all this one was pretty cool presentation..

I always have lack of words while talking... and i am tryin to improve myself with it...

watching a lot of Don Box Videos to improve my talking style...

MS is giving away a set of MUG (with office 2007 logo) ,and a cool small drinking bottle (With Windows Vista logo)...they are really coool, i got a pair for Vandana also, she was delighted to have them...

But, Man ..... Saurav did his pres. (Office 2007) like a GOD, i must say he was perfect with everything, i m trying to create my own style......

19-06-2006

WPF Webcast at Microsoft

Hi,

I am just coming back from the WPF webcast session (http://www.microsoft.com/india/webcasts) from the Microsoft, all in all it was hectic to setup my lappy in the netwrok, so i decided to give the presentation by ppt only; and i miss giving the demos to the dear audience.

Tarun, started the presentation, and we ended on a +ve note that we r coming with a new series of WPF webcasts for a week, and got a positive nod from the managers also.

Here i am providing the temp. link of my ppt's, and some demo.

Follow the link and download the ppt.

http://rapidshare.de/files/23490813/the_source_ppt_and_code.zip.html

Please let me know, if you have any questions, or difficulties downloading it.

Thanks guys

14-06-2006

WinFX Renamed to .net Framework 3.0

The First email, that i got today from Microsoft, said this............whhhhhhhhaaaaattttt?

"WinFx is renamed as .Net Framework 3.0, and InfoCard is renamed as CardSpace", i am not against renaming, and Somesagar judges the point of renaming well, but don't you think that it's too fast of we to develop so many frameworks one by one, when did developers get a breath, to stay still and say 'Ok i am pretty done with this tech."

first Ms launched 1.0, then 1.1, then 2.0, and now 3.0, 3.0 is built over the top of 2.0, and obviously stands a chance to be called a new framework, but it's too early, first MS should freeze the Vista, and then it should quote onto the new framework for it.

Never Mind, guys, that's the life of a developer, keep studying.........

12-06-2006

My Session at MICROSOFT

Last Month i was at MICROSOFT, Delhi, Presenting a session of One Day on Windows Vista (Windows Presentation Foundation exactly :))

The Session was cool, and i am hereby providing the pics of my great audience, you guys were really supportive

cheeeeerz

I'll surely put up a post, regarding who is who, once i got to know all of them, by name, and by personality.

25-05-2006

refer to a namespace in XAML

Hi,

I have been through many problems while mapping a namespaces to a prefix, so that it culd be used in XAML, i figured out how to do it properly, and here is what i found.

Some tips -

1. do not depend upon "Local" keyword, each book, blog discusses mapping with the same leading you to the confusion.

so there are basically two styles to map to a namespace

<?Mapping XmlNamespace="<The XAML name for this namespace>" ClrNamespace="<the name of actual clr namesapce>" ?>

then you can provide the prefix

xmlns:my="<the XAML name for the namespace>"

For ex.

    <?Mapping XmlNamespace="myapp" ClrNamespace="Lap" ?>
<Window xmlns="http://schemas.microsoft.com/winfx/avalon/2005"
  xmlns:x="http://schemas.microsoft.com/winfx/xaml/2005"
  xmlns:my="myapp"

and to refer to an object of a class under this namespace u'll write somewhat like this

here datatemplate is nothing but a template for listbox, for which the datatype is an object of a Class Patient; it's nothing but difining the binding, anyways, we ain't discussing binding here.

2. Shortcut method to refer to CLRnamespace, and provide the prefic at the same place

xmlns:my = "clr-namespace:<TheNameOfClrNameSpace>"

for ex: -

<Window xmlns="http://schemas.microsoft.com/winfx/avalon/2005"
xmlns:x="http://schemas.microsoft.com/winfx/xaml/2005"
xmlns:my = "clr-namespace:Lap"

i doin't think now, u'll face any problem ever with mapping the namespaces

Happy Coding

Old Post – Written on HOLI – WPF Perf and 3D

2010-12-17T13:28:00.001+05:30

05-03-2007

WPF Perf and 3d - Part 1 - Ecosystem of applications

Happy Holi!

I never want to start my conversation with that word "Sorry" which shows any kind of regret…but that's how I feel to make myself wait for writing this long awaited post.

So I was supposed to post about the 3D with WPF and the ecosystem of tools

When I started with learning WPF , that first professional designing tool that I came across with was Aurora…an awesome tool at that time (don't know how it's performing this time, as you had to put in your email id and wait for the download email for each months CTP..which is a pain and the tool was worst with its performance).

The bracket talk must have told by now that I was longing to see other tools come by my way, the Evolution took its course and there it was Microsoft Expression Interactive designer ® Now called Microsoft Expression Blend ®, meanwhile I also saw some 3D tools coming up and people working over some converters to convert a 3D file made in 3ds max, or a file with flash animations to the compatible WPF code with animations.

I have two cases / kind of work that people / designers are with while working in WPF.

What about Developers?

Ans. I expect developers to use Microsoft Visual Studio 2005 with Orcas. No more talks about developers, I'll talk to them only in later posts.

So …let us take the First Case.

Design snapshots and Generate styles

Note – the table is in order of usage

Tool	Usage	Format
Microsoft Expression Graphic Designer	Generate the snapshot picture for the form	Xaml, png, jpg and all basic picture formats
Microsoft Expression Blend	Take the xaml, and pic out the styles to create the style resources for yourself	Xaml – obviously
Microsoft Expression Blend	For animating the objects	Animations are default as resources in xaml, but give them keys if you want the developer brothers to control them

The Second Case

Note: - the 3D graphic tools are with options and usage is limited to the kind of formats they generate, use as per your own budget and case. Optional are marked with Green color, chose at least one

Tool	Usage	Format
Microsoft Expression Graphic Designer	Generate the snapshot picture for the form	Xaml, png, jpg and all basic picture formats
Electric Rain ZAM 3d	Excellent to work with fresh, as well imported formats, the files are not structured properly though when you import from other formats like 3ds, but the tool is good	Xaml
Autodesk 3ds Max	They are not players in xaml, but indeed they are the BOSS of 3D world, you can get to them for generating awesome 3D effects, and port them using ZAM	.3ds files
Blender	A small but powerful tool, can't say more didn't worked much with it.	Xaml
Microsoft Expression Blend	Use the xaml pieces generated using blender or ZAM and animate / place them accordingly, it's fairly simple	Xaml

Alright the ecosystem doesn't end here, there is more.

The project that you create with Blend, is a normal Visual studio project for Orcas, and your developer friend would easily be able to code with the project that you "The Designer' has designed. To make sure that design is not generating any errors you can also run and test you code in blend itself, and can even do a bit of coding as well, though the coding editor matches nowhere to the ease with Visual Studio, but what more a designer can ask for…….

I am exhausted by colors today! Ah ! it's such an awesome festival, one of its kind, I am proud being born as Indian, and human.

Namaste!

Old Post - WPF

2010-12-17T13:27:00.001+05:30

22-01-2007

WPF Perf and 3D - A New Fake Dimension

WPF has lured the public by showcasing the ultimate UI rendering capabilities....

GLASS, Bitmap effects, Brushes, 3D, Animation almost every sort of UI related tech. is mapped in the WPF (Windows Presentation Foundation).

as this is just a blog post i won't go into detail over how WPF works, but would tell you a punch line "WPF bypasses the UI related work directly to Graphic Processor (your graphic card)".

you might ask, what if it doesn't ? / what happens if my super powerful / ultra speedy CPU does it, won't that do ?

answer is Dear, your Graphic processor is especially meant for it, the point was Windows applications were not being able to make use of it, you could have used it earlier, but then go on use GDI / DirectX....that unmanaged kinda environment...ohh...it sucks

What ? ESPECIALLY MEANT?

Answer - dudes, it has certain algorithms as hardware logic on the Graphic board, which does some really complex calculations, that if you leave them to a software process (CPU), they might take 100% more time for getting rendered.

So, now you've got WPF .....

A Dev - "Alright Brij...I'll start coding my new Racing Game in WPF, 3D is there, ANimation is there...what else, and easily programmable....."

Brij - "Boss! it ain't possible first, second you'll require 3 times more better Machines to run the game thus developed"

"Then what WPF is there for"

WPF - is just a UI development tool for win apps, and the animations or such vital gaming operations are not clock bound for WPF, WPF reaches direct to conclusion if the animations are not done in given time, your animation will be skipped to reach the conclusion of storyboard.

We just couldn't even expect photorealism from a WPF scene, no matter how hard youw work.....some things are missing, and they are indeed missed to achieve the goal of performance - How many times do MS had to tell people, it ain't made for GAMES

Well, i'll talk some solid points related to WPF 3D, and it's perf. one by one in the next post meanwhile, if you are ineterested check out the given links to know more about WPF and 3D technologies.....a whole series is coming up just stay tight....i can assure the series won't just be a repetition of these links....they will have more details then these links.....

The best whitepaper over WPF perf. yet

http://blogs.msdn.com/kiranku/archive/2006/10/30/wpf-performance-whitepaper.aspx

The WPF 3D team blog

http://blogs.msdn.com/wpf3d/rss.xml

The Hardware knowledge for better rendering in WPF

http://blogs.msdn.com/wpfsdk/archive/2007/01/15/maximizing-wpf-3d-performance-on-tier-2-hardware.aspx

Here is the plan for my upcmoing posts

1. Ecosystem of applications for 3D developement in WPF.

2. Know how of 3D, and some key functions / algorithms

3. Hardware required / and WPF competence in Computer Graphics (3d, animations)

meanwhile i prepare my contents for these posts, i'll also write up some posts about the contents that people sometime forget to use while coding with WPF.

Old Post - Biometrics

2010-12-17T13:26:00.001+05:30

05-04-2007

Biometrics, how do they work?

Last Night! my sister called me up and asked how does the biometric systems work, and she wanted to understand it before buying a biometric device and start working with it on a project.

so, i wrote a whitepaper over how biometrics work, here is an excerpt of the same......

There are actually 3 phases in the lifetime of an application meant to work with any kind of biometric technology

Installation and configuration of the biometric device
Initialization of device on the basis of parameters
Passing your biometric data and matching with the biometric print of device

I'll discuss each step one by one in detail

But prior to this you need something to work with, and these are:-

A biometric device.
A signing dll, which can be incorporated with your application, so that you can use its functions to initialize the device, enroll the users with the device, prepare the user database, and later use the same database for login etc.

Now, let us get on with our discussion

Installation and configuration of the biometric device

Any biometric device when installed in your system must follow a procedure, in which your application initializes the device and then enrolls the users with it. You can either call it enroll or simply you can call it "Configure".

Enrollment is a procedure in which your device makes a database of user and user's PRINT. User is nothing but an id, but User's PRINT is something interesting, to understand the print you can also compare and say it's the FingerPrint (Which is unique), but see is it always possible that the angle with which your biometric device might be taking the picture of your finger will always be the same, obviously NOT, so what you need is not the picture but some other smart information about the USER'S PRINT.

For ex –

When you enroll a user with the system, you store his / her name and a character based password (in case something goes bad with that biometric identity, like your finger is hurt).

And then your device asks for your user's Print, a PRINT is nothing but a Defer data structure A defer data st. is not made at one go, so what it asks for is to user to give his print at least 3 times to the device, as 3 times is enough to collect all the possible sets of that biometric identity (which could be your face, fingerprint, eyes, speech). You can say user is training the device to understand him / her.

Now let us see how a defer data st. might look like

User Name brij raj singh Password momitaraj

Defer ds1

20,30	50,75	64,76	98,104	65,328
45,34	64,76	19,38	50,75	67,57
24,67	98,104	98,104	20,30	65,328
63,54	39,32	64,76	64,76	39,57

Defer ds2

20,30	70,79	65,328	98,104	50,75
45,34	64,72	67,57	50,75	64,76
24,67	28,102	65,328	20,30	98,104
63,54	39,32	39,57	64,76	39,32

Defer ds3

20,30	50,75	64,76	98,104	65,328
45,34	64,76	19,38	50,75	67,57
24,67	98,104	98,104	20,30	65,328
63,54	39,32	64,76	64,76	39,57

So when a user gives his identity 3 times to the device for ascertaining his / her identity, the device actually creates these 3 data structures.

Initialization of device on the basis of parameters

Device initialization is pretty straight forward by calling some simple API's and then the device waits for the event of user's print by user, till the user provides his / her print to the device.

Passing your biometric data and matching with the biometric print of device

When the user provides a PRINT to the device, the device again makes a defer ds and then matches this defer ds with the earlier provided defer ds for the users existing in the database, now this process is pretty critical, and because we have 3 defer ds for one user, it's very much possible that though the user is genuine but the defer ds doesn't match with either one of them.

There is a simple yet effective way to solve this problem, and that is

Make Hash keys for all the 9 combinations possible, and when the user provides his defer ds, make its hash key and match it up with the defer ds hash keys already with you.

This is how the device actually works but if you are buying a commercial Biometric device they usually come with an API set which you can always plug in and use without thinking how it works.

Old Post - asterisk for java - installation

2010-12-17T13:23:00.001+05:30

07-05-2008

asterisk for java - installation