Balach Masud

When we look at a blurred image, we see that the colors from various objects are spread out in the image over an area around the objects.  Mathematically, this is exactly what is happening.  Instead of the light from one point in the scene corresponding with the light at one point in the image, the light from each point in the scene is spread out over multiple points in the image.   The function that describes this spread is called the point spread function (PSF).  The PSF is also the impulse response of the imaging system, and in applications dealing with blur, is sometimes referred to as the “blur kernel”.

IMAGE COMPRESSION Many different image compression schemes exist, and several, often completely, different methods can be used for each of the different steps in an image compression scheme, and the different methods can often be combined in any way. Some examples are the Matlab implementation of SPIHT which is used as a reference compression scheme here. Also Matlab commands imwrite and imread supports several image formats, many of them include effective compression. The latest versions (from R2010b) also support the effective JPEG-2000 format (JP2 option). The standard JPEG format is also supported but the compression rate is not as good as expected, perhaps the overhead information is relatively large. This page contains several Matlab functions, m-files, a brief explanation and some examples for image compression. The included functions can be used for some of the many steps or stages often done in image compression. It is not a complete finished codec, like JPEG or JPEG-2000. ...

What is Aspect Ration? The height and width on an image is referred to as the aspect ratio. It defines its overall shape, and it is usually shown as W:H where W is width and H is height. The most common aspect ratio today is 16:9, which means that if the width is divided into 16 equal parts, the height of the TV or picture should be 9 parts.   16:9 works great for TVs since that is the format modern TV shows are delivered on, but most movies are made using the cinema standard, which is 21:9. 21:9 is much wider, so parts of the screen need to be filled with black bars above and below the image in order to fit most TVs. These horizontal bars are called ''letterboxes''. Similar to movies, TV shows used to be made using a 4:3 aspect ratio, which is a lot more square than current TVs(this is why 16:9 is often called a widescreen aspect ratio). To fit modern TVs, vertical black bars or 'pillarboxing' is used. We've listed the most common aspect ratios in the t...

ID3 Algorithm: ID3 invented by Ross Quinlan used to generate a tree from a dataset. its precursor of C4.5 algorithm, used in machine learning and NLP domains. it begins with the original set S  as the root node. IT calculates the entrophy  H(S) (or information gain IG(S)) before, it iterates through every unused attributes of the set S on each iteration of algorithm. It n selects the smallest entrophy (or largest information gain)value. the set S is then spit by the selected attribute (e.g age is less than 50, age is between 50 and 100, age is greater than 100 ) to produce subsets of the data. The algorithm continues to recurse on each subset, considering only attributes never selected before.  INformation Gain in decision tree: it is used as mutual information, which is the expected value of the kullback leibler divergance of the univariate probability distribution of one variable from the conditional distribution of its variable given the other one. In general term...

VIrus: A computer program, which is capable of replicating with little or no user intervention. a piece of code causes damage to your computer either by deleting or corrupting files. it multiplies it self to to fill up disk space or randomly access memory space, secretly infecting your computer. these are disguised as games, images, email attachments, websites URls, shared files in instant messsages. Spyware: A computer program, it spies on you. after downloading itelf on your computer either an email you opened website you visited or a program you downloaded. it scans hardware for peronal information and your internet browsing habits. some spyware programs contain keyloggers that will record personal data you inter in to websites, such as password, usernames, email addresses, etc. Adware: Software, that, once installed, tracks your internet browsing history habits and sends popups containing ads related to sites and topics you have visited. it consumes and slows down your computers ...

Image Extensions 1.Jpeg:     Joint photographic experts group, it is the most famous image Extension used for web.jpeg. these are very lossy, it looses alot of information and also effects the quality of image because is makes it small. Almost every digital camera can shoot and save in JPEG format. It is very friendly because it's smaller takes less room and requires less time to upload to a site. Moreover it's less grainy then GIF, the old Kong of the internet roost. Since 1994 JPEG is considered as the standard. Pros of JPEG:     Graphics Interchange format, • 24 color bit, with up to 16 million colors. • Rich colors, great for photographs that need fine attention to color details. • Most used and most widely accepted format. • Compatible in most OS ( Mac, Linux, PC) Cons of JPEG: • they tend to discard alot of data. • after compression, tend to create artifacts. • cannot be animanted. • doesn't support transparen...