All about Graphics

Rachel Grafton

Keely Martin

Claire Whittingham

Megan Webster

Vector VS Bitmap• Files can be classified into two distinct categories, vector

– based images and bitmap images.• Vector based images generally contain well defined

images such as curves and shapes, mathematically information is required when producing these images, this would include information such as circle radius.

• Bitmap images do not rely on mathematical information to be processed, each bitmap image is processed into a grid, the size of each grid will depend on the image resolution.

GIF format• GIF stands for Graphics Interchange Format.• When the program creates a GIF it squashes the

original image down taking care not to lose any data. It uses a simple substitution method of compression.

• There are problems with GIFs. One is that they are limited to a palette of 256 colours or less.

• GIF is the most popular graphics file type on the internet. Generally, GIF files should be used for logos, line drawings and icons. GIFs can also be used to store low-color sprite data for games.

JPEG Files

• JPEG stands for Joint Photographics Experts Group.

• JPEG just throws away parts of an image by dividing the image into squares (you can see these squares on badly-compressed JPEGs).

• JPEG is a good way of storing photos.

Embedded graphic VS Linked graphic

• A linked graphic is stored in the source file where as embedded graphic becomes a part of the document and therefore doesn’t belong to the source file.

• This is done so that the document does not change when the source file is altered.

• This means that only a representation is shown in the document.

• The default setting means that if the source file undergoes modification, the information in the document is also updated.

• For example, when a paint file is inserted into Word, then the original paint file is changed and saved once more. The image in the document does not reflect the changes made.

The Colour Palette

• The colour palette consists of two panels• “Set colour” panel which forms the small palette• “Colours” panel which form the large palette• The small palette is always used on monitors

with 800 x 600 pixels• On monitors larger than this you can change

between the palettes from the options menu

Lossless Compression

• Lossless compression allows information to be compressed and reconstructed without the loss of any information –hence loss less.

• Lossless compression allows files to be saved in the smallest file size, therefore saving vital memory.

• Lossless was recently added to JPEG files as a late addition to the standard.

Bad BMP?

• The BMP file format, sometimes called bitmap or DIB file format is an image file format used to store bitmap digital images, especially on Microsoft Windows and OS/2 operating systems.

• However, Bitmap images are not supported by any web browsers or web coding languages. Therefore, they are not suitable for use as images in a web application.

Using PNG files

• Portable Network Graphics (PNG) is a bitmapped image format the uses lossless data compression. PNG was created as an image-file format not requiring a patent licence and a replacement for GIF format.

• PNG supports both colour and grey-scaled images for tranferred onto the internet and not professional graphics.

What is Flickr?• Flickr is a photo sharing website and web

services suite and an online community platform. • They help to make photos available to others

and enable new ways of organising photos.• In addition to being a popular Web site for users

to share personal photographs, the service is widely used by bloggers.

• Its popularity is mainly due to its innovative online community tools that allow photos to be tagged and browsed