Window function an important term in signal processing. It also called apodization or tapering function. It is useful for various operations, like separtion of band frequences etc.
Several different windows are available. Only two are worth using, the Blackman window and the Hamming window.
Blackman window are defined as,
w(n)= a0 – a1*cos((2*pi*n)/(N-1)) + a2*cos((4*pi*n)/(N-1));
where, 0<=n<=N .
a0=(1-@)/2, a1=1/2, a2=@/2. in blackman window @ equal to 0.16
Now , in case of Hamming windows coefficient are computed from following equation,
w(n)=0.54 – 0.46cos((2*pi*n)/N); where, 0<=n<=N.
Now for sample 74-point Blackman window’s time and frequency domain representation are given below,
For the same point Hamming window’s time and frequency domain is
In this case of blackman window Leakage factor is 0%, sidelobe attenuation -58.1dB and mainlobe width is (-3dB) : 0.0449.
for hamming, Leakage factor is 0.04%, sidelobe attenuation -42.5 dB and mainlobe width is (-3dB) : 0.0351.
After convolution this two windows we will get time and frequency domain like this,
Leakage factor is 0%, sidelobe attenuation -72.2dB and mainlobe width is (-3dB) : 0.0273.
so this result is more better than before. I called it FSwind 🙂
Finally 🙂 I’m so much happy and excited to annouce the launch of my new site Virtual FS (VFS). It’s a Design, Portfolio and all about my artwork and enjoyment where I will get in touch with my clients and as well as my cutie, sweety , lovely friends and viewers. The main theme of Virtual FS is bring some different in my design. Those who already went my previous sites they can compare the differents of Virtual FS. Now this is an experimental version of VFS , Later will add more features……….
Don’t forget to give me a shout or comment . simply click VirtualFS.
Breaking CAPTCHA: Getting Naughty with Computer Vision……. And Captcha Breaking Experiment in PHP…. These terms now familiar to us. 1st one was made possible by Nadim vai and 2nd one by M. M. Rifat-Un-Nabi. Their post makes me inspire to get naughty once again more simply and more easily. Because I like simplicity ;). I also choosed SomeWhereInDhaka.Net Captcha to do this experiment.
The SomeWhereInDhaka.Net CAPTCHA suffers several weaknesses: fixed font face, fixed font size, no distortions and it’s easy to segment. In this experiment, I have developed simple algorithm to break the SomeWhereInDhaka.Net CAPTCHA.
- At first need the captcha image from the page, We can do it in two way :
(a) capturing only the captcha portion [I have used php function: imagejpeg()] or,
(b) capturing the page image by php function and then crop only captcha portion from that page.
- So, we got that captcha. Now sampling that captcha image
- Match sampling pattern with reference pattern. If matching is true then it will give output, In this case the captcha value. (No need any edit distance algorithm)
You can see the effect here.
I post my website ads 😛 as spam. So, isn’t it more simple.
And finally a sympathy will goes for SomeWhereInDhaka.Net. And also I would like to thanks them because they not change there captcha yet. and it help me to make this experiment :D. So, my friends if wana see weak captcha then what are you waiting for – just log in to SomeWhereInDhaka.Net and keep getting naughty :P.
During the developing my homepage which is virtual FS, I was tried to bring some vampiric design on it. So, for that purpose I have create a hand which holding an old paper. I think it looks like vampiric :D.
It is very simple and it tooks only 20 min . Now.. lets see how it was happen…..
At first I make a Hand sketch using normal Pen tool in PS. then after finishing sketch it looks like this…
Then its time to fill hand sketch with appropriate color. I choose #E9CF9B value for hand color.
Nail sketch And Add Shadow
Then Sketch nail and also fill with color #A38D1E. Then adjust color brightness, contrast, saturation, gradient map, curves; here I used
a parabolic curve. Then it becomes ….
Now its up to you. How more and more realistic photo you can make.:)
I chooce an old paper and bring my hand art on it.
Finally I add this in to my homepage.
And thats it ……………… enjoy 😉
I think all of us know about facebook. A social networking site. Accoriding to Global Alexa page ranking Facebook postion is 5th. In my point of view, the best part of the facebook is facebook developer app. Its makes FaceBook more different and resouceful for developer.
FS MUSIC MANIA. This is a musical application. People can listen music by using this app.
You can invite your friend. I have used FBML tag <fb:multi-friend-selector> Which will allow you to invite multiple friend.
You can also add a profile box for FS Music Mania, in to your profile.
For this purpose simple need to add
$facebook->api_client->profile_setFBML(NULL, user_id, ‘profile’, NULL, ‘mobile_profile’, ‘profile_main’);
Then it will be like this………….(pic from fsmania)
So, Keep rocking with music and give me your feedback about FS Music Mania.
Vector graphics formats are complementary to raster graphics, which is the representation of images as an array of pixels, as it is typically used for the representation of photographic images.
In short Raster is composed of pixels and Vector is composed of paths. Both are use in Graphics Designing. Now vector graphics,
It’s an important part in 3d Modeling, animations and graphics designing.
I found something more interesting and funny art in vector graphics with photoshop. Last night I have tried to make a vector graphics of my own picture:). And Now I would like to share this.
Its seem to me very interesting and much enjoyable. Although it doesn’t require any special ability you should be proficient in the use of the Photoshop or any other designing software. Your Drawing skills would also help can help you lot.
First of all make a shape of the image. My photo shape like this….
Color is the Heart of Graphics
Choose body, cloth and other object color. And fill it. I choose #EACC2D for my body.
I think I have forget to do somthing 😉 but what is that ……. Oh!! i got it.. I have forget to wear my eyeglass:).
That’s all :D. Don’t you think its so interesting.. After finishing this picture I also little bit surprised to see myself in vector graphics.
another vector after 1 year. that same guy….
A few days ago, some of my friends inform me , when they open my site www.engr-faisal.co.nr in IE7 or higher(in beta version) then their browser giving a message, which is “Out of memory at line ##”.
Actually I use Opera 9.23 as my default browser and also IE6 and others. But I never faced this type of problem. Even my site working pretty nice with all browser except IE7.
Actually “Out of memory(OOM)” case in modern computers when the operating system is unable to create any more virtual memory. If all of its potential backing devices have been filled. Such a system will be unable to load any additional programs and since many programs may load additional data into memory during execution, these will cease to function correctly.
The Operating systems such as Linux will attempt to recover from this type of OOM condition by terminating a low-priority process, a mechanism known as the OOM Killer.
This behavior can occur if the desktop heap in the WIN32 subsystem is depleted. Because in Windows NT 3.4’s default heap size is 512K , and 3072K in case of Windows NT 3.1.
Now how to remove this OOM message :(?
Okay .. To correct this problem, we may increase the size of the desktop heap. But before do this you have to know, how to modify the registry. Otherwise it can cause serious problems if you modify the registry incorrectly. For more information about how to back up and restore the registry you can read this article.
Now get ready………………
From the Edit menu, choose String.
Increase the SharedSection parameter.
SharedSection specifies the system and desktop heaps using the following format:
Add “,256” or “,512” after the yyyy number.
SharedSection uses the following format to specify the system and desktop heaps:
Increase the zzz number to “256” or “512.”
Hope this will help to prevent OOM.:)