1. The term "pixel" is actually short for "Picture Element." These small little dots are what make up the
images on computer displays, whether they are flat-screen (LCD) or tube (CRT) monitors. The screen
is divided up into a matrix of thousands or even millions of pixels. Typically, you cannot see the
individual pixels, because they are so small. This is a good thing, because most people prefer to look
at smooth, clear images rather than blocky, "pixelated" ones. However, if you set your monitor to a
low resolution, such as 640x480 and look closely at your screen, you will may be able to see the
individual pixels. As you may have guessed, a resolution of 640x480 is comprised of a matrix of 640
by 480 pixels, or 307,200 in all. That's a lot of little dots. The term resolution is often used for a pixel
count in digital imaging, even though American, Japanese, and international standards specify that it
should not be so used, at least in the digital camera field. when the pixel counts are referred to as
resolution, the convention is to describe the pixel resolution with the set of two positive integer
numbers, where the first number is the number of pixel columns (width) and the second is the
number of pixel rows (height), for example as 7680 by 4320.
Computer displays are made up from grids of small rectangular cells called pixels; the term comes
from "picture elements". The picture is built up from these cells. The smaller and closer the cells are
together, the better the quality (resolution) of the image, but a larger file is required to store the
increased pixel count. However, modern storage devices and working memory have gigabyte, even
terabyte capacities, so there is less need for particularly compact forms of data. In computer
graphics, a raster graphics image, or bitmap, is a dot matrix data structure representing a generally
rectangular grid of pixels, or points of colour, viewable via a monitor, paper, or other display
medium. Raster images are stored in image files with varying formats. A bitmap corresponds bit-for-
bit with an image displayed on a screen, generally in the same format used for storage in the
display's video memory, or maybe as a device-independent bitmap. A bitmap is technically
characterized by the width and height of the image in pixels and by the number of bits per pixel (a
colour depth, which determines the number of colours it can represent).
File Formats
The BMP file format, also known as bitmap image file or device independent bitmap (DIB)
file format or simply a bitmap, is a raster graphics image file format used to store bitmap
digital images, independently of the display device especially on Microsoft Windows and
OS/2 operating systems.
PNG is a graphics format specifically designed for use on the World Wide Web. PNG enable
compression of images without any loss of quality, including high-resolution images. Another
important feature of PNG is that anyone may create software that works with PNG images
without paying any fees - the PNG standard is free of any licensing costs.
A common format for image files, especially suitable for images containing large areas of the
same colour. GIF format files of simple images are often smaller than the same file would be
if stored in JPEG format, but GIF format does not store photographic images as well as JPEG.
TIFF is a file format for storing images, popular among graphic artists, the publishing
industry, and both amateur and professional photographers in general.
JPEG is a commonly used method of compression for digital photography (image). The
degree of compression can be adjusted, allowing a selectable trade-off between storage size
and image quality.
2. PDF is a published document file containing text and images that cannot be changed without
its sourcefile.
EPS is a file format that provides an electronic image of text or text and graphics that looks
like a printed document and can be viewed, printed, and electronically transmitted.
AI is a proprietary file format developed by Adobe Systems for representing single-page
vector-based drawings in either the EPS or PDF formats. The .ai filename extension is used
by Adobe Illustrator.
It can be useful or necessary to compress for ease of storage or delivery. However, while
compression can save space or assist delivery, it can slow or delay the opening of the file, since it
must be decompressed when accessed. Some forms of compression will also compromise the
‘quality' of the file's content. Digital compression is a complicated science. This section offers a non-
technical introduction. If it still seems a little complicated, don't worry. The most important
distinction to grasp is that of 'lossless' and 'lossy'
The image capture device may be a camera or a scanner. Both use the same basic image capture
technology. A camera is a device that records/stores images. These images may be still photographs
or moving images such as videos or movies. An image scanner—often abbreviated to just scanner—
is a device that optically scans images, printed text, handwriting, or an object, and converts it to a
digital image. Common examples found in offices are variations of the desktop (or flatbed) scanner
where the document is placed on a glass window for scanning. Hand-held scanners, where the
device is moved by hand, have evolved from text scanning "wands" to 3D scanners used for
industrial design, reverse engineering, test and measurement, orthotics, gaming and other
applications. Mechanically driven scanners that move the document are typically used for large-
format documents, where a flatbed design would be impractical. Both a camera and a scanner use
digitalisation. The process of converting documents or objects into digital form so that they may be
read, stored, managed and transmitted electronically by a digital computer.
Optimization is the process of modifying a software system to make some aspect of it work more
efficiently or use fewer resources. In general, a computer program may be optimized so that it
executes more rapidly, or is capable of operating with less memory storage or other resources, or
draw less power. The optimized system will typically only be optimal in one application or for one
audience. One might reduce the amount of time that a program takes to perform some task at the
price of making it consume more memory. In an application where memory space is at a premium,
one might deliberately choose a slower algorithm in order to use less memory.
A data storage device is a device for recording (storing) information (data). Recording can be done
using virtually any form of energy, spanning from manual muscle power in handwriting, to acoustic
vibrations in phonographic recording, to electromagnetic energy modulating magnetic tape and
optical discs. A storage device may hold information, process information, or both. A device that
only holds information is a recording medium. Devices that process information (data storage
equipment) may either access a separate portable (removable) recording medium or a permanent
component to store or retrieve information. Asset management is the process of managing the
physical assets of a plant, oil rig, or other facility or infrastructure including the facilities used in
production. It enables companies to optimize and improve maintenance productivity and facility
uptime.
