General Concepts for DTP

General Concepts of DTP  

• Bit / byte :

Bit is a smallest unit of data in a computer which carries information along with it. It is a binary digit. It can hold only one of two values : 0 or 1. So sequence of bit carries information along with it.

8 Bit = 1 byte

Computer storage is often measured in MB, GB, etc.

Unit                                                   Equivalent

1 kilobyte(KB)                               1,024  bytes

1 megabyte(MB)                           1,048,576  bytes

1 gigabyte (GB)                             1,073,741,824  bytes (1024 MB)

1 terabyte (TB)                              1,099,511,627,776  bytes

1 petabyte (PB)                             1,125,899,906,842,624  bytes

• Pixel :

Smallest individual element of digital image is called as 'Pixel'. Each pixel is composed of sequence of bits. In an 8-bit gray scale image, the value of the pixel between 0 and 255.

A pixel is also known as PEL.

• Resolution :

Resolution is defined as no. of pixels the image holds within it. i.e. the term resolution refers to the total number of count of pixels in an digital image.

For example. If an image has M rows and N columns , then its resolution can be defined as M x N.

Higher is the pixel resolution , the higher is the quality of the image.

We can define pixel resolution of an image as 4500 X 5500.

Usually resolution is measured in PPI (Pixels Per Inch) or DPI (Dots Per Inch).

• Color Modes :

RGB - Red Green Blue

RGB or Red, Green and Blue, are additive colors and are what we see when we look at our computer monitors and televisions screens. The tiny dots that make up our displays are composed of RGB information. The RGB color space is very large and is ideal for images that would be used for web and presentation purposes.

CMYK - Cyan Magenta Yellow Black

CMYK or Cyan, Magenta, Yellow and Black, are subtractive colors are the standard ink colors for printing. This means that whenever we print an image, we are using CMYK inks to produce the print.

• Image File Formats/ File-Extensions :

JPG    -    Joint Photographic Expert Group (JPEG) (.jpg / .jpeg)

PDF   -   Portable Document Format (.pdf)

PNG   -   Portable Network Graphics (.png)

PMD  -   Page Maker Document (.pmd)

PSD   -   PhotoShop Document (.psd)

CDR   -   CorelDRAW (.cdr)

GIF     -   Graphic Interchange Format (.gif)

JPG :
- It is highly used format for all cameras.
- In small size, it provides excellent picture quality.
- This file format is excellent for real world photographs & still life photography.
- It can display millions of colors and provides nice shadings of light & dark.

PNG :

- It stores image in its high end editing process with and without   preserving transparency to the background.

- It is highly used in traditional animation industry.

- It is Excellent file format for Logos.

- Provides file size heavier than JPEG.

GIF :
- This file format is used for storing Graphic Elements.  
- This file format has animation capabilities.
- Provides file size smaller than JPEG.
- This is widely used in web-brochures in current trends.

• General Image Classification : Bitmap & Vector Images

1. Bitmap (Rastor) Images :
-  An image that is composed of pixcels and each of different color arranged in a format of rows and columns to display is known as Bitmap (Raster) Image.
-  Raster images are highly resolution-dependent.
-  It is highly supported format used in web and this is the format which is suitable for editing photographs.
-  It provides excellent color-editing aspects.
-  But it blurs when blow up, so it is not suitable for higher end scaling as the quality of image goes low.

2. Vector Images :
-  The image formed with the nodes, shape and fill, calculated using the mathematical formula is known as Vector Image.
-  Vector images are resolution independent i.e. highly scalable.
-  Vector-based softwares are widely used for creating Text-Files, for creating Icons, Logos, High-end Hoardings, etc.
-  But it is not good for color editing job work.
-  Also big drawback of it is, that we have to convert it into raster for the use in web.

Visit Our Website