Different Image File Formats

.JPG
Most common file type, it uses compression to make the file smaller but the smaller the image size the lower the quality of it, used for photos a lot, it is a raster file type. Has a lossy compression, once the file is shrunk, making it big again reduces the quality.

High compression - Low quality

 Low Compression – High Quality

.GIF
Stands for Graphics Interchange Format, can be used for drawing and line art, maximum of 256 colours so not too good for photos, lossless image format and has pretty low image size. It is also a raster format. GIFs can also be used for short animations.

.PNG
Stands for Portable Network Graphics, it is a lossless format as the images keep their quality, it has a larger file size and is good for photos. It also can support transparency.

.PSD
Main format used in Photoshop, it is a lossless format and it is very high quality. Stores a lot of other information with in the image like layers, masks and transparency, because of this it has a larger file size. It is a vector image format.

.BMP
Short for Bitmap, it is a high quality image type and doesn’t use compression at all which leads to huge files sizes. It is a raster image format. They’re only really used by Microsoft.

.TIF
Stands for Tagged Image File, it is a raster image format and is usually has a lossless compression. They are usually high quality images and store other information with the image so have large file sizes.

.AI
Used in adobe illustrator, this is a vector image format as it is mostly made from lines and contains instructions on how to recreate the image, no matter what the size.

.TGA
TARGA stands for Truevision Advanced Raster Graphics Adapter, they can store image date with either 8, 16, 24 or 32 bits of precision per pixel (24 bits of RGB and 8 on alpha channel). The colour data can be colour-mapped, in direct colour and true colour format.

Image Capture Devices

Camera
A camera takes a picture of the exactly what it ‘sees’, the quality of the camera’s images is measured in megapixels. Cameras can have different lenses dependant on what type of photo you wish to take. It is the most common form of image capture. Photographers use very high quality cameras for their work and often have many different lenses for them. Most mobile phones have cameras built into them too.

Scanner
A scanner copies an actual document, letter, book, magazine and even photos by scanning them in taking a picture of them it then saves them as an image. Scanners are mostly used in business as you can quickly send a printed out document to someone by scanning it in and emailing it to someone. Some scanners can change a printed document back into an editable document so you can change it again afterwards, which is good if you have deleted or lost the file. Most modern printers have a scanner built into them.

Graphics Tablet
A graphics tablet is designed for capturing drawing, as you use press the pen to the tablet, it acts as a mouse for the drawing program and captures you’re movements exactly. They can even measure how hard you press down with the pen, and make the lines lighter or darker on the screen.

Storage of Image Assets

File Size
Images for games must be as small as possible as there is limited space on the disc they will go on, but need be high quality for the graphics to still look good, this is why many games are more than one disc, on the PS3 this isn’t a problem as it uses Blu-ray discs which are much bigger.

File-Naming Conventions
Images must be named appropriately so you know exactly what the image is, this is important of there is a problem with one of the images as you need to locate it quickly, and many images can make up a person for example so you need an exact and descriptive file name

Pixel and Resolution

What is a pixel?
A pixel is the smallest part of a picture, they are arranged in a grid to make up a picture and each pixel is a different colour. The more pixels in the image, the bigger it is.

Image Resolution
Image resolution is the actual size of the image, usually measured in pixels, the most common image sizes are 800x600 and 1200x800.

Raster Image
Raster images are made up of pixels in a grid. These tiny dots of different colours make up the image. They are resolution dependent which means that resizing the image reduces quality of it. Rasters are easily converted to other raster formats. They are restricted to a rectangle and have a very minimal support for transparency.

Popular Raster formats:
• BMP
• GIF
• JPEG, JPG
• PNG
• TIFF
• PSD

Vector Image
Vector images are made up of individual and scalable objects which are defined by mathematical equations rather than pixels, so they always render at the highest quality. Objects may consist of lines, curves, and shapes with editable attributes such as colour and fill. They are scalable and will always look good no matter what size; a good example of a vector is fonts on a computer. They don’t have any background, it is transparent. They are inappropriate for photo-realistic images because it isn’t possible to make a photo into a lot of lines and colours.

Popular Vector formats:
• AI (Adobe Illustrator)
• PNG
• PSD
• TGA
• TIFF

Image Optimisation and Compression

Images must be compressed to a suitable size for their purpose (optimization), for example images that will be used on websites need to have a small file size but still be good quality so that they load quickly on lower internet speeds whilst still looking good. Similarly, images used in games need to have a small file size as there is limited space on the disk, but need to be high quality so that the game itself still looks good. Optimizing images often reduces the quality or the resolution of the image to make it a smaller file size. Sometime changed the format the image is in can reduce the size.

Game Art

Photo Realism

What are they?
A very high detail art style where everything is made to look as real as possible this means it uses a large number of colours. This often requires HD graphics and a lot of processing power, it looks best on PCs as they can process the higher detail. It can be difficult to tell the difference between high detail photorealistic games and films.

What do they look like?
Almost real life and not a video game at all because of the high level of detail, makes the player feel part of the game because they can immerse them self in it.

Famous games in this art styles - include some screenshots/box art etc.
Crysis – It is used though out Crysis to make the game more realistic and it makes it nicer to play.

Cel Shading

What are they?
A quite simple art style that uses black outlines a lot for definition and doesn’t use particularly high detail much, can often look like it has been drawn or from a comic.

What do they look like?
Looks like it has been drawn, like a cartoon or comic book.

Famous games in this art styles - include some screenshots/box art etc.
Borderlands – It is used throughout the game to give a hand drawn and unique look.

Exaggeration

What are they?
Exaggerating certain parts or items to make them look different than they normally would, for example stretching eyes out to be bigger. Bright colours can also be used to exaggerate things.

What do they look like?
Looks cartoony and unrealistic, can be used in both. Manga art is a popular example of this, especially in China and Japan and tend to be on the Nintendo consoles.

Famous games in this art styles - include some screenshots/box art etc.
Phoenix Wright – Uses a magna style which exaggerates characters facial features making them look unrealistic, but makes them stick in your mind more than an average normal looking character.

Abstraction

What are they?
A strange and unique art style, nothing tends to resemble any real life object, often uses a lot of lines and strange shapes, can also use different colours.

What do they look like?
Can look like pretty much anything as it doesn’t have to make sense or be logical, usually bright colours.

Famous games in this art styles - include some screenshots/box art etc.
Child Of Eden – Uses a lot of brightly coloured lines and shapes throughout the game.

Game Art Styles

2D Sprites

What are they?
They’re a 2D image or animation that can be put into a larger scene. They a usually a png because it has a good compression and supports alpha channels and colour pallets.

What is the purpose of it?
Easy way of putting characters on screen and making them move/animate.

3D Isometric Sprites


What are they?
A sprite that looks like the image is 3D when it is not; it just uses shadows and angles to look 3D, Again these are usually png files.

What is the purpose of it?
It’s a rather easy and cheap way to make the game look 3D.

Concept Art (e.g. Character, Weapon, Vehicle, Environment)


What are they?
Artwork based on a game, the artist’s impression of a character or level. Can be done before release to show what the game is like, or after release by fans of the game. It is usually made digitally but not always. The best file format for them is TIF as they are high quality and have lossless compression, but are often converted to jpegs for use on the internet.

What is the purpose of it?
It shows the style of the game without revealing the game itself.

Textures (e.g. Face, Surface, Building)


What are they?
They’re images that wrap around a model to make an object or person.

What is the purpose of it?
To make an in game object look more realistic, by making it look shiny, smooth, rough, spikey etc. by adding lights and shadows in the right place.

In Game Interface


What are they?
The menus in game they can include inventories, health bars and other icons.

What is the purpose of it?
They make the game easier to play and look better when played.

Printed Media (e.g. Box Art, Manual, Poster, CD)


What are they?
Artwork that comes with or advertises the game.

What is the purpose of it?
Box Art – Make someone want to buy the game.
Manual – Explain how to play the game/ how the game works.
Poster – Advertise the game and make people want to buy it.
CD – Make the CD look interesting rather than just a plain disc. Tells you what game it is easily.