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.