File Format Research.

BMP
Bitmap is the most basic format. When saving files in this format, you have to choose the operating system bewteeen Windows or OS/2, the image depth should be upto 32bits. However it doesn’t save information on layers or channels. BMP files are a historic but still used format. They can be black and white and coloured pictures. However only upto 24bit. It is structure into 3-4 parts:

 The ‘header’ section stores the position of the image data, the ‘information header’ part stores imformation like how many colours the picture has and the width and height of it.
There are 4 types of compression that the BMP file supports:
0 – no compression
1 – 8 bit run length encoding
2 – 4 bit run length encoding
3 – RGB bitmap with mask

TIF
Stands for Tagged Image File, most graphics software packages have this file format this is because it allows you to share different platforms and programs. A TIFF file formatted image will include LZW compression which won’t lesson the quality of an image and also ZIP compression and helps keep transparency. It was first created to store pixel image data in the 1980′s. A problem with TIFF is that no singular software package can read all of its vallid files. It is sectioned into 3 different parts.

JPEG
JPEG (“jay-peg”) is a simplified image compression mechanism.  JPEG stands for Joint Photographic Experts Group, the name of the committee that wrote the standard.
JPEG is designed for compressing either full-colour or gray-scale images
Of natural, real-world scenes.  It works well on photographs, naturalistic
artwork, and similar material; not so well on lettering, simple cartoons,
or line drawings.
as you can see the detail in the text has gone blurry.
JPEG handles only still images, but there is a related
standard called MPEG for motion pictures.
JPEG is “lossy,” meaning that the decompressed image isn’t quite the same as
the one you started with.  (There are lossless image compression,
but JPEG achieves much greater compression than compared to one that has a lossless method.)
JPEG is designed to exploit known limitations of the human eye,
notably the fact that small color changes are perceived less accurately than
small changes in brightness.  Thus, JPEG is intended for compressing images
that will be looked at by humans.  If you plan to machine-analyze your
images, the small errors introduced by JPEG may be a problem for you, even
if they are invisible to the eye.

Vectors and Rasters.

The difference between vector and raster graphics is that rasters are made of pixels, and vectors are made of paths. Rasters are file formats like gif and jpeg, they are composed of an array of mixed colours which make the image.  Vector files, are files like Adobe Illustrator  and esp. they are made of path or curves, the data file for a vector contains where the path starts and ends, how much it bends and the colour that is in it. Because vectors are not pixels it means it can be changed in size without the image losing its quality.There is a third graphics format type which are Metafiles. These can contain both raster and vector components.

Pixels

Is short for picture element, a pixel is a single point in a graphic image. Graphics moniters display pictures by dividing the display screen into thousands (or millions) of pixels, arranged in rows and columns. The pixels are so close together that they look connected.
The number of bits used to represent each pixel decides how many colors or shades of grey can be shown. For example, in 8-bit colour mode, the colour monitor uses 8 bits for each pixel, making it possible to display 2 to the 8th power (256) different colors or shades of grey.
The specific color that a pixel describes is some blend of three components of the color spectrum – RGB. Up to three bytes of data are allocated for specifying a pixel’s color, one byte for each major color component. A true color or 24-bit color system uses all three bytes.
Screen image sharpness is sometimes expressed as dpi (dots per inch). (In this usage, the term dot means pixel, not dot as in dot pitch.) Both the physical screen size and the resolution setting determine dots per inch. A given image will have lower resolution – fewer dots per inch – on a larger screen as the same data is spread out over a larger physical area. On the same size screen, the image will have lower resolution if the resolution setting is made lower – resetting from 800 by 600 pixels per horizontal and vertical line to 640 by 480 means fewer dots per inch on the screen and an image that is less sharp.

BIT DEPTH

Bit depth is used to describe the number of bits used to store information about each pixel of an image. The higher the depth, the more colors that are available for storage. The bit depth of an image will determine how many levels of gray (or color) can be generated.