Graphical file formats

The features and limitations of graphical files folder’s

Raster Graphics – A raster graphic is a file format that is used as a type of format for saving images/image files. It is the data structure that is used by images saved as this format and it is made up from and represented by a rectangular grid that can be made up from pixels or points of color and it is viewable on paper, on a monitor/computer screen or another form of graphic display medium.

Raster graphics correspond bit-for-bit with the image that is being displayed on screen and is mostly displayed in the same format that is used for its storage in the displays video memory, or as another independent bitmap. Raster graphics can be characterized by the width and height of the image in pixels and by the number of bits per pixel.

Advantages of Raster graphics

1. It displays true filled areas on the images and gives a realistic image

2. The images refresh rate is independent form the scene complexity is faster than some other file formats that are used and also the refresh hardware that is required is lower in cost than others.

Disadvantages of raster graphics

1. The size of a raster graphic cannot be scaled effectively as when you manipulate the size of the image it can become distorted and pixelated when the image is enlarge.

Vector graphics – A vector graphic is a digital image that is created and made up from colors which information is stored as a series of mathematical calculations and they are made up from paths and form these paths they make use of the mathematical relations between points and the paths that connect them to describe an image.

Advantages of Vector graphics

1. Vector graphics have the major advantage of being able to scale them to any size without any loss in image quality which is a major advantage for image editors.

2. Also another advantage of vector graphics is that they do not take up a lot of hard disk space so it saves memory on your computer

Disadvantages of Vector graphics

1. Vector graphics require your computer to work harder in order to display the particular image on screen and also because of this it may take longer for the image to be displayed on screen.

2. Vector graphics are not as good as other file formats for representing detailed graphics, so they cannot be used effectively to display photographs and other similar complicated images

J-Peg images – J-Peg stands for joint photographic experts group and it is a standardized image compression mechanism and it s designed for compressing either full colour or grey scale digital images of real world pictures/images.

Limitations - It works well on photographic images, artwork and other similar material but it does not work as well on things like lettering, black and white line drawings and simple cartoons.

Advantages – JPEG is a good format for producing photos, it can be used for the format of any photo that you have and/or want to submit and most in not all most all web browsers support the JPEG file format

Disadvantages – JPEG uses lossy compression algorithm so some of the images detail will be lost if/when it is changed to other file formats like a BMP to JPEG image but usually in the case of photos it is not noticeable. If an illustrated image or vector image is converted to JPEG it is possible for the edges of lines of the image to become blurred so it is advised to use a lossless compression format like the GIF format.

GIF images – GIF stand for Graphics interchange format and the image is in the bitmap format.

The GIF format has up to 8 bits per pixel in the image and this allows a single image to be able to reference up 256 distinct colours. The colours in the image are chosen form the 24-bit RGB colour space. The format supports animations and this allows the user to separate the palette of 256 colours in the image for each frame in the animation.

Limitations – A main limitation of the GIF format is that it is unsuitable for reproducing colour photograph images and other images with continuous colour because of the 256 colour limit however the GIF format works well with simpler images such as the creation of animation.

Advantages – GIF uses lossless compression algorithm when converting to other file formats this means that none of the detail of the original image is lost in this conversion. Images that use 256colours or less or grayscale images that are saved to the GIF format will not loose any detail in the conversion. GIF Images can have transparency and can be used in animation.

Disadvantage - The main disadvantages of the GIF format is that is has a 256 colour limit so if you are saving an image as a GIFF folder for example changing a picture from JPEG to GIFF there will be some of quality in the image.

JPEG Image                                                                                         

GIFF Image   

TIFF images – TIFF stands for Tagged image file format and it is used mostly for the storing of images and it is popular among the users of Apple Macintosh users, graphic artists and the publishing industry. Tiff files are usually the best quality output form a digital camera.

Advantages of the TIFF format is that it is a flexible format that can use lossless or lossy file compression algorithm also the storage algorithm is included as part of the file.

Disadvantages of the TIFF format is that it is used almost exclusively as a lossless image storage format that uses almost no compression at all which is fine for image quality but not for file storage as the file sizes can be quite big.

PNG images – PNG stands for portable network graphics and it is an image that uses lossless data compression. The PNG was created in order to improve upon and replace the GIF file format as an image format that doesn’t require a patent license.

Features – PNG supports a palette – based images with the palettes of 24 bit RGB and/or 32 bit RGBA colours and grayscale images that do or don’t use the alpha channel .

Advantages – PNG does not require a patent license and supports 24bit RGB and/or 32 bit RGBA

Disadvantages – PNG was designed mainly for transferring images over the internet and not for printing images so it therefore does not support non RGB colour spaces such as CMKY.

BMP Images – A BMP images is sometimes referred to as a as a bitmap image or Device independent bitmap/ DIB and it is a format that is used for the storage of bitmap digital images mostly on the MS (Microsoft) Windows operating systems.

Image before change to bitmap 

Image after change to bitmap 

File Compression Techniques

File compression is when you take a data/image file and compress the size of that image so that it takes up less space on a computers hard drive when the image is save to it.

Lossy compression – When using lossy compression some of the quality/data of the file that you are compressing is lost as a result of saving it as a lossy file type however before saving it as a lossy file type it is assumed that you already know this and have taken it into consideration. In graphical images lossy compression some of the images resolution may be lost in order to create the smaller file size the loss may be may be in the form of the depth of the colour or the graphical detail of the image an example of this would be the high resolution details of an image can be lost if the image is displayed on a low resolution device.

Lossless compression – With lossless compression the data/image files size is compressed without any loss to the data/quality of the image yet the size of the file is still compressed in size.

Resolution and Colour depth

Resolution – Resolution is the term that we use to describe the dot or pixels used in the displaying of an image for example a high resolution images is created with more pixels so this results in the image looking crisper and cleaner.

A factor that can change an images resolution is the stretching of the width and height of that image, after stretching an image so much it is going to effect the quality of that image.

Before resolution change

 Image after resolution changes 

As you can see from the images above you can see that the quality of the image has pixilated with the changes that I have made to the size of the image, the image after the changes has lost a lot of its quality after the resolution changes.

Colour depth – The depth of colour displayed on images refers to how many bits of information that are being used to represent the colours of each of the pixels that are in the image so in general the more colours that are used in the images usually mean that better quality of that image but there are other factors that effect the quality of an image.

          

Hardware and software used in digital graphics

Hardware and software used in digital graphics

Software

Paint – Paint is one of the most basic  graphic creation and editing software package, the software has the advantage of coming free with all of the windows operating systems this gives the user the advantage of having free graphic manipulation software free with there PC, another advantage of with software is the simplistic nature of the software, as it is very easy for the average computer user to work with, however this also works as a limitation of the software as it gives the user less choices on ways to create, edit and manipulate an image with it than if you were creating an image with a more advanced software package but because the program is free the user cant really complain much about the limitations of the package.


Key functions and features of paint – Paint as the name suggests in its most basic form is a blank canvas that users of the program can use to create an image from scratch using the tools that are provided on the program or they can do very basic edits to an existing image by opening it with paint.
In paint you can use a variety of tools to create and edit images, for creating an image you can use the pencil tool - this tool allow you to draw freely with the mouse cursor also you can change the thickness of the line that you are drawing the disadvantage to this is that what you draw is only as straight as you hand is steady, there is also the brush tool which works in the same way as the pencil tool but the difference is that you can choose a variety of styles and thicknesses of brushes that can make the image you are creating or editing look more unique looking, this tool has the same disadvantage as the pencil tool being that the image you create with the tool is only as straight as your hand is steady.
The eraser tool allows you to delete/rub out anything that you have drawn in the paint program similar to how you can rub out pencil in real life, you can change the size of how much the eraser tool erases by clicking on the different size lines in the size tool to make it erases

The picture above shows the use of auto shapes and the eraser rubbing out parts of an auto shape, also it shows the pencil tool and some of the different brush types also in the screen shot you can see some of the different options you have with paint such as the brush sizes, the color of what is being drawn on screen and the text box.

Sumo paint 

Sumo paint is a free online image editing program that offer all of the image editing functions that paint has on top its own functions that allows the user of the program to go into greater detail with image editing. The best thing about the program is that it is free so this means that almost everyone in the world has access to an online image editor that is not online free and offers all of the functions of Paint but has far more of its own functions. The only limitation/disadvantage of this software is that without the help of a guide it is very hard for the user to figure out how to work all of the image editing tools. (paint being very easy for the user to figure out how to use)

Once the user has gone on to the sumo paint website they click on open sum paint and this opens the program in a new browser and then the user can open a new image on to sumo paint.

The image that is opened will appear on screen and it will also be represented in the layers box, this box allows the user to place one or more images on different layers according to what order the user wants the images to appear in for example a background image and a foreground image.

The layers box will also contain any image effects that the user decides to include on the image for example if the users hovers the cursor over layers and when the drop down box appears clicks on layer effects they will be able to chose different effects for the image layers for example clicking on inner glow it will a box will appear allowing the user to change the settings of the effect then after they have choose the settings and clicked ok the effect will change the image.

Another tool that is available with sumo paint is the clone tool. With the clone tool say you have two images open in sumo paint -

-and you like the colour/texture of one image and want to use it on an other, well with the clone tool you go to the colour/texture/image you wish you use and hold down the "Ctrl" and "Alt" keys and then hover over the areas that you wish to copy with the clone tool-

-After this you let go of the key and then select a brush style of your choice you will then be able to paste the copied portion of one image onto another image, this offers a great advantage in image creation as it allows the user to take textures and colours from other images and make use of them in the creation of their own image, this allows the user to create very unusual, creative, and unique images.

Hardware for creating/getting these creations on to the computer 

Graphics tablet - In digital graphic there are many different ways for the user to create and manipulate images and the graphics tablet offers a lot of advantages for the user in the creation of images and animations. 

The main function of the graphic tablet is that once plugged into the computer and the correct hardware having been installed on to the computer the tablet takes over the functions of the mouse with the use of a stylus pen.

This offers a huge amount of advantages for graphic creators and artists as it allows them to be able to draw what they want straight on to the computer (providing the correct software is open for example MS Paint) with pin point accuracy with how they would be able to draw with their own skills with a pencil and a piece of paper, on top of this it allows the user to change the style of the image they are creating with the software they are using for example in MS paint the user has access to different brush types, once selected that brush type no becomes what the user draws with so it offers a wide range of different brush like tools that the user has access to, not only this but the user can also change the colours that they are using to draw an image at anytime for example if you are drawing an image in MS paint in the colour black and you wish to colour in want you have with a different colour you can click on a different colour and brush style and then colour in the selected area just like you would in real life with the stylus.

Graphics tablet also play a major role for the animators of cartoons as the tablet allows the artist to create a character for an animation with out having to draw it out and then scanning it on to the computer and converting it on to the relevant software in order for it to be edited instead of this the drawn character is already on the computer as soon as the animator has drawn it, this offers the advantage of saving time as the animator does not have to spend time scanning an image on to the computer.

Scanner 

The scanner is a piece of hardware that allows the user of it to scan anything that will fit into the scanning tray on to the computer where from there it can be used for a wide range of graphic editing software such as sumo paint. 

To use a scanner the user has to first make sure it is connected to the PC usually by a USB lead and then turn the scanner on, the computer should recognize the scanner if the relevant software and then once this has happened the scanner should then be ready to use. 

In comparison to each other both a scanner and a graphics tablet offer the user the ability to get/create images on to the computer the main advantage that a scanner has over a graphics tablet is the wide range of things that the user is able to get on to the computer with it, with a graphics tablet the user has to create or manipulate an image with the stylus and this is good for users who have skills with art but for those that don't it allows them to take anything from photos to leafs and get them on to the computer for use in an image editing program. 

A user of a graphic's tablet for the most part can only create an image with the skills that they have as an artist and with these skills they can go a long with with the hardware and software that they are using for an image but to recreate something as an image depends on what they are drawing for example if they wish to draw a leaf depending on their skills they could draw a very accurate representation of it but how ever they would not be able to recreate every last detail of the leaf including the exact colours of it and it texture but with the use of a scanner the user can have the object in this case a leaf scanned on to the computer depending on the quality of the scanner an almost exact replica of the leaf can be brought on to the computer from here the user can bring it into a program such as sumo paint and use the clone tool to take the colour and textures of it and paste them on to another image that is opened in the program other things can be scanned in for this purpose to such as fabrics, wallpapers, etc 

A scanner allows the user to take pictures and things like magazine images and put them on to a computer from here the user can open them in photo editing software and use them to bring certain object featured in the picture on to another image that is open in the software for example scanning a car to edit in sumo paint. 

The main limitation's of a graphics tablet is that the image that the user creates with it rely's on the user's art skills for the quality of the image but with the scanner exact image can be scanned on to the PC. 

The main limitation's of a scanner is that the quality of the image that get scanned on to the computer depends on the quality of the scanner for example a high end scanner will produce a very life like copy of an object/photograph on to the computer for use but a low end scanner will produce the copy on to the computer but it will have less quality and textures than it would have in real life, also in lower end scanners scanned image's and objects can become blur'ed during the transfer on to the computer and if you want to get the highest quality copy of something on to a computer using a scanner you will need to use a high end scanner which can be quite costly for some one to go out and buy and it may be hard to find a service close by that has a high end scanner available for use.

 

Performance of a computer system

 HARD DRIVE 
The hard drive or hard disk is the part of the computer that allows the user to store their data/software/etc. the hard dive of the computer can affect the overall performance of the PC as the bigger the hard drive the more you will be able to store on the computer, also if the hard drive on a computer is full the computer will tend to run slower.

 Graphics Card 
The graphics card is the part of the computer that is in control of  rendering the on screen image that will be displayed on the PC's screen. A graphics card can effect the over performance of the PC as if it is outdated or is not fit for the intended purpose, it can cause the on screen graphics that you have loaded to run at a slower rate and this can also cause lag time in the PC's controls.

 Processor 
The processor or CPU is the brain of the computer it controls everything that goes on inside your computer. The type and size of the processor in your computer can affect the overall performance of your computer as a faster processor will let your computer function faster and more effectively than a smaller one. 

RAM

Random access memory, or RAM, is a type of memory used in

computers that can access data in any order. RAM stores data for

programs and processes that are running on a computer in order to

make the data easily accessible, allowing the program to run and be
accessed quickly.
Ram can affect the performance of as having less or outdated ram can
make the computer run at a lower speed and make loading time’s
increase, but by adding up to date and more ram chips can increase the
computers overall performance and speed.

Hardware Components For Digital Graphics

There are various hardware componenets that can be used to create and manipulate digital graphics. I will noew describe these componenets

Mouse

A mouse is a electronic device that controls the movements of the courser on the computer screen as you move it around.In digital graphics a mouse is used to move and manipulate images, select options, etc on screen.

Screen/Monitor

A screen/monitor is used for displaying the on screen aspects of the of the computer, depending of the quality of the screen it may give a less clear or more clear image.

In digital graphics it is used to view on screen graphics , or to view graphics that have been stored on an other device.

Digital Camera

A digital camera is used for taking pictures of almost anything, after the picture has been taken it can be stored on the camera and be manipulated by the camera options provided on some cameras, also they can be upload form the camera on to the computer to be stored and or manipulated through computer programmes.

In digital graphics a digital camera is used to acquire images that can be uploaded on to a computer and manipulated through digital graphic programmes.

Scanner

A scanner is an other method of getting images on to a computer by selecting an image that you want to put on to your computer, opening the scanner and putting it in and then selecting the scan function on the scanner.
In digital graphics a scanner is used to get images on to the computer for use in digital graphics software for editing.
http://www.youtube.com/watch?v=2yS-d4IjWG0 

 USB Storage
 A USB storage drive is used in order to save and store documents, images, etc for later use, back up copy, or to move the documents form one pc to another. In digital graphic a USB storage stick can be used in order to store graphic’s related documents, or to take a document form one computer to another.

Flash Cards
A flash card is a mini storage device that uses flash memory, the storage capacity can range anywhere from 8 megabits to several gigabits. In digital graphics flash cards are used in most digital camera’s as the only or additional memory on top of the camera’s built in memory.

Graphics tablet  

A graphics tablet is a device that takes over the function of the mouse and allows for precise movements of thecursor.

In digital graphics a grpahic tablet can be used for by grpahic designers in order to draw images to a precise level of detail that could not be achived by a mouse for editing in software such as photoshop. It can also be used by graphic designer’s to create image’s to edit and animate.

Printer 

A printer a piece of hardware that is used to print out images from a computer, camera, flash card, etc.

In digital graphic’s a printer can be used to produce high quality images that have high levels of detail and resolution.