Wednesday, 5 February 2014

Image Capture, Optimisation and Storage

There are many different medium you can use to capture a digital image like scanners, digital cameras and graphics tablets.

A scanner is a device that copies an image and can then show this image on screen or print it onto paper.
The scanner will take multiple images of each section on the thing your trying to scan and then at the end of the scan it puts them all together into one image.

The key features to look out for when buying a scanner is the DPI (Dots per Inch). DPI are the amount pixels are detected per square inch. The higher the DPI the more pixels per square inch which will give you a higher resolution image, but with higher resolution the file size is going to be increased as well.

There are many types of scanner like All-in-one, Plane, Mouse, Document & Wand.


  • All-in-one scanners are useful because like there name indicates they have all the functions you need in one scanner. This will include a scanner/photocopier, printer, email & fax. These are good because they have multiple functions in one and you don't need to but each device separately you have it all in one machine. Generally these printers are cheaper and the quality is quite low. This is because as it has more functions put into it, and each individual function that the scanner has is a basic version. So you will have low DPI scanner, photocopier will be slower producing copies, etc.
  • Plane/flatbed Scanner only have the function to scan an image and transfer it to an output device like a PC or server. This scanner can vary from a cheap scanner that scans with low DPI but will cost you a lot less than an all-in-one. But you can also get more expensive scanner with up to 6400 DPI which will get us a lot better quality image.
  • Mouse scanners are PC mouses with a built in function to also scan. This is possible because modern day mouses have a laser below it allowing it to shine on something you want to scan and it takes little images and recomposes the image into one image once finished scanning over it with the mouse.
  • Document scanners are more an industrial scanner used in businesses so you would see them in an office, in schools where you need a lot of paper work for kids, in a paper shop that does photocopies for people. These scanners will have a low DPI because there function is to print a lot of copies of word document and not intended for images.
  • Wand scanners are small portable scanners that you can carry round and scan an image quickly and don't need to take the object you want to scan to a printer you just carry the printer round with you. These scanners usually will have blue-tooth so they transfer straight to the PC and are quick to use around an office.

Scanner are useful devices to copy an image or object but these have to be static objects and can't be moved while scanning otherwise you will only get half the image you wanted. To get an image of something that moves you can use a digital camera.

Digital cameras have been commonly used for the past 20 years and are a great way to take an image of something while you are away from home. While scanners have to be plugged into somewhere and can only really operate inside a building, a digital camera can be used any where. A digital camera is a camera that takes video or still photographs by recording images on an electronic image sensor.
The resolution of a digital camera is often limited by the image sensor that turns light into discrete signals. The sensor is made up of millions of "buckets" that essentially count the number of photons that strike the sensor. The brighter the image at a given point on the sensor, the larger the value that is read for that pixel. Depending on the physical structure of the sensor, a color filter array may be used which requires a demosaicing. The number of resulting pixels in the image determines its "pixel count". For example, a 640x480 image would have 307,200 pixels, or approximately 307 kilopixels; a 3872x2592 image would have 10,036,224 pixels, or approximately 10 megapixels. There are 3 main types of digital cameras and they are: Compact, SLR and mobile phone.


  • Compact are the most common cameras that people use in day to day life, if they are to take images while on holiday or at a birthday event these type of cameras are cheap and easy to use. We can get good quality images with the compact that are available at the moment.
  • SLR are bigger and more professional based cameras. These cameras are a lot more expensive than a compact because they can be upgraded as needed and have lots of addons. When you buy an SLR you will get the base which will look like a compact. You can then change the lens so it's bigger so you can zoom in closer and get high quality images from further away. You can get other addons like tripods to help you take photos without having to worry about moving a tiny bit and ruining the image.
  • Mobile phones have incorporated cameras on the back and most of them on the front as well. These cameras are usually worse quality than the other 2 types of cameras but are getting a lot more powerful as hardware is improved. The Nokia Lumia has a 20 megapixel camera which is just a bit lower than a compact camera. But as you will all ways have you're phone on you because it is a essential thing to have on you it makes the choice a bit harder whether to buy a specific camera just to take images or get a phone that has all the functions that a phone has from calls, msg, internet, etc and also have a camera with just a little worse camera.

The key features to look for when buying a camera are: Image resolution, sensor size, screen size, zoom lens, video recording, card compatibility, burst shot.


  • Image resolution are the amount of pixel that an images has. The higher the resolution the more pixels it has and the better detail the image will have.
  • Sensor size. Each camera will have a sensor that detects light. The bigger the sensor the higher the resolution is and the better quality image you will receive.
  • Screen size is the size of the screen on the back of the camera. This is useful to preview the image after you take it so that you can check if there were any mistakes while taking it and can retake the image if needed.
  • Zoom Lens are used to zoom in closer without losing quality of the image so you can get high quality images from far away. This also removes fish eye.
  • Video recording is supported with virtually all camera nowadays and allows you to capture an image as a video so you can see it moving.
  • Card compatibility. Most cameras will have a SD card expansion so you can take more images than the camera memory can take. Some cameras will only support a certain size memory card so check this before buying. You can also transfer images from the on board memory to a SD card.
  • Burst shot. This is a function that allows you to take multiple images at once. This is useful so you can get loads of images of the same thing and choose which you like. The paparazzi use this to take lots of images at once of famous people and can get the best images of them.

Each camera will have there strengths and weaknesses. A compact will be reasonably cheap with about 20-30 megapixels and are very portable to carry round with you.They can range around £200-£800. SLR are a lot more expensive because you have to have different parts for to get the quality image you are looking for. They will have better quality image with over 40 megapixels and capable of zooming a lot further. These cameras are the best for quality but weigh a lot more than a compact, are more complicated to carry round and can cost in the £4000+ range for a dissent one. Mobile phones like said before have been getting stronger hardware so they can get up to 20 megapixels in a phone which is a device we use regularly. The mobile phone will probably cost more to buy than a compact but has the extra features. It will probably be better to spend a bit more on a phone with 20 megapixels than to get a 24 megapixel compact because the phone you will all ways carry with you and is very portable and the compact is another device that you don't want to carry round with you if you have you're phone.

The last device that hasn't been mentioned yet are graphic tablets. Graphic tablets don't capture images but allow the user to draw an image and transfer it to the PC or other device. A graphic tablet detects the point that the user is pressing on the tablet and transfers this to the PC. This allow you to draw an image as if you are using a pencil, allowing you to get a lot higher detail image than what you could draw with a mouse.
There are 2 different types of graphic tablets that are: standard grey based tablet that detects where you press and transfers it to the PC and tablets that have a screen and you draw straight on to it.

The main features you need to look for when buying a graphic tablet are pen pressure sensitivity, keys, multi-touch and wireless.

  • Pen pressure sensitivity is how much pressure you apply to the tablet and this will change how you draw. If you apply more pressure the lines are thicker and clearer to see. When you apply less pressure the lines are small and can be less clear.
  • Keys: This is the amount of keys that the tablet has. These keys can be used to zoom in on the image, activate/deactivate touch and many other fast action keys.
  • Multi-touch. This option detects more than one finger at once allowing for more functions.
  •  Wireless. This is whether or not it has wireless. The battery life isn't the best so this option isn't the best option to have and just keep to wire.

The basic version of the tablet is the cheaper option and can still be used for any work that the other one can use. The price of these can vary from £50-£500, the more expensive ones give you a high pen pressure and keys. The graphic tablet that has a screen is a lot more expensive and can cost around £2000 but allowing you to draw as if you were drawing on paper this gives the best quality image.

Every image has a different purpose, whether this is just to keep for memories or to use on the web. Sometimes the basic image format that you get when you capture the image isn't good enough for the purpose. If you are using the image for a webpage that millions of people visit you don't want the image to take forever to load and take time to download, you want it to appear instantly and download fast. To do this the image has to be optimised. There are many different things to take into account when optimizing an image like: target image output, image bit depth, image resolution, image dimensions, compression, file size and file naming conventions.


  • Target image output: This is what the image is for. If its for the web it will need to be high quality but as low a size as possible, if it's for a billboard the size doesn't matter but the quality needs to be good.
  • Image bit depth: This is the amount of detail there is in each pixel.
  • Image resolution: The quality of the image. The higher the resolution the better the quality.
  • Image dimensions: The size of the image is important because if it's a logo for a billboard the image will need to be big and high quality to fit the billboard otherwise it will be stretched and look terrible.
  • Compression: The type of compression and how much it has been compressed. There are many different types of compression from JPG to TIFF and these can be compressed more or less. The higher the compression the lower the quality but takes up less space on the hard drive.
  • File size: How much the file takes up on the hard drive. The smaller the amount the less space it will take up but having a smaller image size means that the quality is going to be worse.
  • File naming conventions: Naming the file correctly so people know what it is and what its intended for.

These optimization will change depending on the purpose of the image. For a web image you need to have a small image dimensions, as small a file size as possible, JPG compression, image resolution doesn't really matter but will influence the file size and image dimension. If the image is a logo for a billboard the image should be as large as possible, high resolution so its detailed, high bit depth, small compression (png or tiff), the file size doesn't matter for this.

When modifying images or any type of software a good way to keep all your data safe is to use asset management. Asset management lets you download the asset you want (an image or file), modify it as you need and re save it on the cloud. Each time you save it creates a new copy of it so it automatically makes an incremental backup of the current asset you are using. Additionally it can make backups every so often while using the asset and tells you who used the asset last. This is great because you know who used what asset and if anything goes wrong you can use an older asset and nothing is lost. The is great because you always have backups of everything you use and you know if somebody else has changed your work. The only bad side to this is that with so many copies it takes up a lot of space on the hard drive and as all of this is saved on a server it will probably have a RAID 0 or 5 which means it will have multiple hard drives backing up each file.

All of these things are useful in the games industry because you will need to capture images for references for the game, optimise the image for the purpose whether it's just a reference or a texture for the game and store the file with multiple backups that everyone in the company can access to be able to use it as well.

Wednesday, 6 November 2013


File Types and Formats Blog Notes

 Image Properties


Pixel


A pixel is a single dot of an image. An image is composed of loads of pixels.

This is an image



This is the equivalent of a pixel (couldn’t go any smaller). This represents the bottom corner of the image and the image has hundreds of these.

Image Resolution


Image resolution is how many pixel there are in an image, a picture that only has 10x10 pixels is good quality but very small if we make this picture bigger the image becomes pixelated because it adds pixels you are adding pixels that don’t exist but if you had an image of 50x50, the image could be seen better at bigger size because there are more pixels to use.


This image shows the difference between the amounts of pixels used as you see a 10x10 is small and if made big is blurry and a big picture that has more pixels made bigger is only partially blurry.

Pixel Colour Intensity


It is the amount of colour used in the image. So if an image is in RGB format the image colour intensity is the amount of red, green or blue used in the image. Each colour is represented in black and white with black being more intensity of that colour and white being less intensity.
 

This is an image with lots of colour

 
This is the red channel which shows the amount of red used (more red intensity is black and less is white and the grey colour is the middle between the 2)

 
This is the same as the last but with Green

Same as before but with blue

Types of Pixel Colour Intensity


There are 2 different colour intensities:

RGB: Red, Green and Blue this type of colour intensity is good for digital use like looking at it on a PC or camera.

CMYK: Cyan, Magenta, Yellow and Key (Black) this type of intensity is good for printing.

Compression

When we compress something this becomes a lot smaller in file size so that it doesn’t take up as much space on our hard drives. There are 2 different types of compression used in images which are Lossy and Lossless

A lossy compression is when an image is reduced and the pixels that aren’t needed in the smaller file are deleted. The data that has been deleted can’t be recovered so it can’t recover its original size. Lossy compression are good for big detailed pictures because they reduce the amount of pixels in the image which reduces the data usage on your hard drive.

Lossless compression saves the pixels away so the image can be made bigger and smaller without the picture becoming pixelated. Lossless compression is good for logos that need different sizes (logo on front of building big, logo on a piece of paper small or on a call card which is really small).

Types of digital graphics


Raster Image


A raster image is an image made of pixels and each point of the image is saved as a colour. We would use this type of images for posters or other big drawing that use lots of colours. When we zoom in on the image is because pixelated (because it’s made of pixels) this way it is only good to use to an image that has a fix size and doesn’t need resizing. This makes the files smaller. 

Some of the Raster image formats are: JPEG XR, TGA, ILBM, IMG, PGF, etc.

BMP


Introduced on Windows platform. Commonly used raster graphic format for saving image files. The BMP format stores colour data for each pixel in the image without any compression. A 10x10 pixel BMP image will include colour data for 100 pixels. This method of storing image information allows for crisp, high-quality graphics, but also produces large file sizes. The JPEG and GIF formats are also bitmaps, but use image compression algorithms that can significantly decrease their file size. For this reason, JPEG and GIF images are used on the Web, while BMP images are often used for printable images.

Uses lossless compression.

Can’t hold transparency or animation.

GIF


Designed by CompuServe in early days for computer 8-bit video, always uses lossless LZW compression, but uses an indexed file (8bits, 256 colours maximum), very good for web graphics, one colour in indexed colour can be marked transparent, allowing underlaying background to be seen, doesn’t save the dpi number for printing resolution, supports animation showing several sequential frames fast to simulate motion.

Tiff


This file format is lossless which means the image doesn’t get pixelated when zoomed on. It has the highest quality format for commercial work. Lossless compression. From 1-bit to 48-bit colour. It does support transparency but it can’t hold animation. This file format is good for graphic artists, publisher industry and photographers because it has the highest quality image format.

Versatile, many formats supported.
Mode: RGB or CMYK or LAB, and others, almost anything.
8 or 16-bits per color channel, called 8 or 16-bit "color" (24 or 48-bit RGB files).
Grayscale - 8 or 16-bits,
Indexed color - 1 to 8-bits,
Line Art (bilevel)- 1-bit

JPG


The file is much small than other standards because it uses lossy compression which means we get smaller files but a the cost of quality. Good for web pages, email, memory cards, etc.

RGB - 24-bits (8-bit color),
Grayscale - 8-bits

Can’t hold transparency or animations.

This type of image is used in most cases for its small file sizes and is easy to carry around lots of images like for photos.

Vector Images


A Vector image is an image where the image is made of shapes and each bit has coordinates saved to it so when we zoom in on the image it recalculates the coordinates so that the image stays the same and we don’t get a blurred pixelated image. This type of image is good for logos because we need the logo big on the front of a building or a small calling card and using the type we can make 1 logo and just resize it. This type of image uses a lot of memory because it keeps the colours doesn’t matter the size.

Some of the Vector image formats are: XPS, PPT, VML, AI, CDR, .dwf, .dwg, etc.

PSD


This is the Photoshop standard that is one of the few formats that supports all of Photoshop’s features. File size can be very large if we are working with lots of layers. Can be reopened and modified if needed.

It uses lossless compression

It can hold transparency but not animation.

This file format is used for making and modifying anything in Photoshop or InDesign programs.

Fla


Fla is the adobe flash standard that lets us modify the images in flash. This format is similar to photoshop because it uses lossless compression and holds the layers like PSD but can also use animations unlike PSD.

Ai


Ai is adobe illustrator file format that lets us make vector images.

Wednesday, 23 October 2013


Computer Game Graphic Types

2D Sprites


2D sprites are images used to represent a thing in a game, these things can be characters (main player or sub playable characters), objects (capsule, coin, fruit), enemies (big bad a baddies, mobs, creeps), etc. Everything (except the background image) are sprites in a 2D game.

In this image of mario we can see loads of different sprites like mario, mushroom, blocks, tubes, etc.
Different types of sprites

3D Isometric Sprites


A 3D isometric sprite is a 3D model of a character, object, and enemy and with that model you take an image of it at isometric angle. They do this to give the image depth and give the illusion of 3D but requires a lot less graphics to process so that low powered machines can run them. The sprites are made like a 2D sprite (Frame by frame) and are used in a games like sims, strategy games like command and conquer and most MOBA type games like DOTA (Defence of the Ancients)  and LOL (League of Legends).

 

Concept Art


Concept art are the initial designs for a game and are what the rest of the games development team have to base their work on. Concept art is needed for virtually everything in the game like characters, weapons, vehicles, environment, etc. Once the concept art is made 3D modellers can start working on these designs and create the concept art as a 3D model and add other details if needed. Concept artist are usually freelancers that go from one job to the next and are only really needed at the start of the project.

 

Textures


When a 3D model is created it is made in a shade of grey but that is no good in a game, so it needs colour. Textures are those colour that are applied to a 3D model. But in order to apply the texture the 3D model needs to be “unboxed” so to say where we need to unfold the model so it is flat add the texture and rewrap the model back together. There are different types of textures like Normal map, colour map/diffuse map and a specular map. A colour map is when we add all the colour to the model (the end result looks like this). A specular map is used to add shine to the model, the model is made up of black and white colours and the white parts represent shine/highlights and the black is not shine (Matt). The last one is a normal map which is coloured in blue and give fine detail to models like scratches.

Colour Map
Normal Map
Specular Map
All three of the same texture
 
In game Interface

An in game interface are feedback and interactive images that appear on screen. In a game you will have a heads up display (HUD) which will give simple but useful information to the player like (maps, remaining ammo, what button needs to be pressed to interact with something, etc. The graphics needed to make a game interface are 2D images that represent each thing on screen like icons that represent the weapon equipped with the amount of ammo left, minimap, etc.


In this example there is a minimap at the top right, remaining missiles just below it, health bars at the top of the screen, a radar at the top left, the current type of weapon equipped at the bottom right.

Printed media


There are different types of printed media used in video games like Box art, manuals, posters, etc. These are one of the most important aspects of creating the game because they will be the first impressions that the player see’s when he walks into a shop or looks it up online and can determine if they buy the game or not. The art used on these need to be eye-catching and show what the game is more or less about.

 

If we look at this box art of infamous 2 we see the main character and that the game is most likely a magic type game because the character is using lightning, there is also blue one side and red the other which gives off a good and bad effect which most gamers would see as a game where you choose whether to be good in the game or evil.

Wednesday, 16 October 2013

Graphical Styles
Every game is created with different graphical style which makes that game unique in its own way. The most common graphical styles used are Photo-realistic, Abstraction, Cel-shading and Exaggeration. Most genres use the same visual style because they work better in that certain genre like most FPS games are photo-realistic but there are some exceptions like borderlands.

Photo-realistic

Photo-realistic is when a game or rather something in the game is made from a picture from real life. Games that use this style are a lot of first person shooters like battlefield and Call of duty.
These games use this style to make the player feel like they are on a battlefield and at war and the players think they are this person in the middle of a battlefield giving orders or being ordered to save or kill somebody.
The colours used are very realistic like real life and make the viewer feel like it is something that could happen in real life or in the past.
 This graphical style is made so that the player feels like he is in the shoes of the avatar and everything done in the game is something that you do in real life (most times) but we wouldn’t do it (like shoot somebody).

Abstraction

Abstract art style often employs a lot of lines and geometric shapes that don't resemble any real-life objects. To abstract something is to simplify it, reducing it to a few essentials and basic forms instead of trying to reproduce it. Indie game developers use this style a lot because it is easy to create and doesn't require a lot of time or money to create. Plus the thing you create can be anything from your imagination and doesn't need to be compared to real life meaning it can't criticised for its graphics or art style. Games that use this style are Fez and Super Hexagon.


 

Cel-Shading

Cel-shading is a type of rendering which makes a 3D model look hand drawn.Games that use this style are borderlands and Catherine.
This style usually has the drawings outlined to give off a hand drawn effect and usually got a lot of bright colours and is a style between photorealistic and cartoon. The colours used make the viewer like they are watching drawings move.

Exaggeration

This style is a very non-realistic style where everything is created with everything being too big/powerful/impossible to exist in the real world like swords twice the size they should be or characters that body mass is bigger that it should be. Games that are exaggeration are most anime games like Naruto or games like Gear of War (Chest is really big).
The colours are usually bright and make the viewer feel like they have powers or magical items exist.


These are the most used graphical styles used in games and each style makes that game into hours of entertainment for the user, if the graphical style doesn't work then people won't buy the game.  Each graphical style gives a game a different feel to it which makes the game unique.