About New Year 2010

Hi Visitors,

    I wish you Happy New Year 2010

Know your Laptop

Know your Laptop

Laptop has many advantages then desktops that are completely portable, and they use less power and make less noise. Also, they're often a little slower and have less graphics and sound processing power. Laptops are more expensive than desktops but now a days price gap between both are small. Prices are laptop falling than desktops.

Did you imagine how can all the components found in a desktop fit into such a small package? And how can laptops be efficient enough to run on battery power alone? I will try to deliver the answers for the above queries and some of the others about laptops too. Lap­top and desktop computers are very similar that they have the same basic hardware, software and operating systems. ­­A desktop computer includes a motherboard, display card, hard disk drive and other components in a cabinet. The monitor, keyboard, and other peripherals connect with cables through the ports.

A laptop, however, is much smaller and lighter than even the most compact PC tower. Its screen is an integrated part of the unit, as is its keyboard. Instead of a cabinet, a laptop uses a small, flat design in which all the pieces fit together comfortably. Because of this primary design difference and because of a laptop's natural portability, components have to

• Fit into a compact space
• Conserve power
• Produce less heat than desktop components

Often, these differences make the components more expensive, which can contribute to higher laptop prices. In the following sections, we'll examine how laptops handle these differences.

Laptop Processors

The microprocessor works as the computer's brain. The CPU produces a lot of heat, so computer uses a fan and a heat sink -- a system of plates, channels and radiator fins used to draw heat off of the processor -- to cool off. Since a laptop has far less room for each of these cooling methods, its CPU usually

• Runs at a lower voltage and clock speed - This reduces heat output and power consumption but slows the processor down. Most laptops also run at a higher voltage and clock speed when plugged in, and at lower settings when using the battary.
• Mounts to the motherboard without using pins - Pins and sockets take up a lot of room in desktop PCs. Some motherboard processors mount directly to the motherboard without the use of a socket. Others use a Micro-FCBGA (Flip Chip Ball Grid Array), which uses balls instead of pins. These designs save space, but in some cases mean that the processor cannot be removed from the motherboard for replacement or upgrading.
• Has a sleep or slow-down mode - The computer and the operating system work together to reduce the CPU speed when the computer is not in use or when the processor does not need to run as quickly.

Laptops usually have small fans, heat sinks, heat spreaders or heat pipes to help dissipate the heat from the CPU. Some higher end laptop models reduce heat even further with liquid coolant kept in channels alongside the heat pipe.

Laptop Memory and Disk drives

A laptop's memory can make for some of the reduced performance that comes from a slower processor. Some laptops have cache memory on or very near the cpu, allowing it to access data more quickly. Some also have larger busses, allowing data to move between the processor, motheroard and memory more quickly.

Memory types used in laptops

• Small Outline Dual Inline Memory Module (SODIMM)
• Dual Data Rate Synchronous RAM (DDR SDRAM)
• Single data rate Synchronous RAM (SDRAM)
• Proprietary memory modules

A laptop has an internal hard disk drive, which stores the operating system, applications and data files. A laptop hard drive is physically smaller than that of a desktop. In addition, most laptop hard drives spin more slowly than desktop hard drives, reducing both heat and power consumption. Many laptops use a modular design, allowing a variety of drives to fit in the same bay. These drives come in three different designations:

• Hot swappable - The computer can stay on while changing the drive.
• Warm swappable - The computer can stay on while changing the drive, but the corresponding bus (the path the drive uses to send data to the CPU) must be inactive.
• Cold swappable - The computer must be off during the swap.

Laptop Screen, Graphics and Sound

A graphics processing unit (GPU) is a microprocessor that handles the calculations necessary for 3-D graphics rendering. Most laptops have graphics capability built into the motherboard or have smaller graphics cards with a GPU designed specifically for laptop use. GPU manufacturers ATI and nVidia both make GPUs specifically for laptops. Laptops frequently share memory between the CPU and the GPU, saving space and reducing power consumption.

A laptop displays its graphics on a liquid crystal display (LCD) screen. Most screens measure between 12 and 17 inches, and the size of the screen affects the overall size of the laptop. In addition, laptop screens can be:

• Black-and-white (16 grayscale) or color (65,536 colors)
• Active or passive matrix
• Reflective or backlit

Active matrix displays have sharper images and are easier to read, and backlit screens are better for low-level lighting conditions.

Laptop Batteries

Laptop is portable and can run on batteries alone. Details of the battaries are

Nickel-Cadmium (NiCad) batteries were the first type of battery commonly used in laptop computers, and older laptops sometimes still use them. They have a life of roughly two hours between charges, but this life decreases with each charge based on the memory effect. Gas bubbles form in the cell plates, reducing the total amount of available cell space for recharge. The only way around this is to discharge the battery completely before recharging it. The other drawback of NiCad is that if the battery charges too long, it can explode.

Nickel-Metal Hydride (NiMH) batteries are the bridge between NiCad and the newer Lithium-Ion (LiIon) batteries. They last longer between charges than NiCad but overall have a shorter total lifespan. They suffer from the memory effect, but to a lesser extent than NiCad batteries.

LiIon batteries are the current standard for laptop computers. They are light and have long life spans. They do not suffer from the memory effect, can be charged randomly, and won't overheat if overcharged. They are also thinner than any other battery available for laptops, making them ideal for the new ultra-thin notebooks. LiIon batteries can last for anything from about 950 up to 1200 charges.

Many laptops with LiIon batteries claim to have a 5-hour battery life, but this measurement can vary greatly depending on how the computer is used. The hard drive, other disk drives and LCD display all use substantial battery power. Even maintaining wireless Internet connectivity requires some battery power. Many laptop computer models have power management software to extend the battery life or conserve battery power when the battery is low.

Tips for Purchase Laptops

Laptops are available in a huge variety of configurations, with a wide range of options and capabilities. Here are a few things to keep in mind when you shop for a laptop

• Processor speed and memory -- These two factors will greatly affect the laptop's performance.
• Screen size -- A larger screen can make a laptop better suited for playing games or watching movies.
• Weight -- As laptops get more powerful, they also tend to get bigger and heavier.
• Upgradeability -- Options for adding memory or a faster hard drive can improve performance.

Some of the Manufactures

Sony

Dell

HP

Acer

Image Processing

Introduction to Image Processing

Modern digital technology has made it possible to manipulate multi-dimensional signals with systems that range from simple digital circuits to advanced parallel computers. The goal of this manipulation can be divided into three categories:

* Image Processing image in -> image out

* Image Analysis image in -> measurements out

* Image Understanding image in -> high-level description out

We will focus on the fundamental concepts of image processing. Space does not permit us to make more than a few introductory remarks about image analysis. We will restrict ourselves to two-dimensional (2D) image processing although most of the concepts and techniques that are to be described can be extended easily to three or more dimensions. Readers interested in either greater detail than presented here or in other aspects of image processing are referred to

We begin with certain basic definitions. An image defined in the "real world" is considered to be a function of two real variables, for example, a(x,y) with a as the amplitude (e.g. brightness) of the image at the real coordinate position (x,y). An image may be considered to contain sub-images sometimes referred to as regions-of-interest, ROIs, or simply regions. This concept reflects the fact that images frequently contain collections of objects each of which can be the basis for a region. In a sophisticated image processing system it should be possible to apply specific image processing operations to selected regions. Thus one part of an image (region) might be processed to suppress motion blur while another part might be processed to improve color rendition.

The amplitudes of a given image will almost always be either real numbers or integer numbers. The latter is usually a result of a quantization process that converts a continuous range (say, between 0 and 100%) to a discrete number of levels. In certain image-forming processes, however, the signal may involve photon counting which implies that the amplitude would be inherently quantized. In other image forming procedures, such as magnetic resonance imaging, the direct physical measurement yields a complex number in the form of a real magnitude and a real phase. For the remainder of this book we will consider amplitudes as reals or integers unless otherwise indicated.