Unit 78: Digital Graphics for Computer Games - Research

Unit 78: Digital Graphics for Computer Games - Research Exercise

Aim: Understand theory & application used for Computer game graphics

File Extensions

A file extension are the characters at the end of a file name. File extensions are always placed after the fullstop (after the file name). An example of this would be 'stone1.tiff'. 

This is shown in the example below. 

ALL FILE EXTENSIONS ARE DIFFERENT AND ARE USED FOR VARIOUS PURPOSES

Ideal file extensions for Photography

The best quality image format is a TIFF. This is because of lossless compression (the image can be compressed without the quality differing). However, TIFF files are one of the largest file types so may not be ideal if storage is a problem. TIFF files are widely used commercially for photography because the images will not lose quality . JPEG images (.jpg) are the smallest file types and are one of the most used file types for images. However, this isn't suitable for commercial use because the smaller the file is, the more it will lack quality. But, JPEG images are ideal because they are decent quality and are a small file size so can be used for general  photographs where high quality is not important. 

Graphics (logos, line art)

PNG (.png)  file extensions are widely used for creating graphics like logos. This is because PNGs are high quality images that can be used on the web. They also offer the option to withhold background transparency. GIFs can also be used for graphics on the web, but do not withhold transparency of the background. GIFs are smaller files than PNGs.

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Compression

Compression is the reduction of the number of bits needed to represent data. This means that the file size is reduced, so that the file can save storage capacity, speed the time taken for files to transfer, and lower the costs for additional hardware such as; hardrives. 

Compressing data can be lossless or lossy.  Lossless compression enables the restoration of a file to its original state, without the loss of a single bit of data, when the file is uncompressed. Lossy compression permanently removes bits of data that are not needed. Lossy compression is useful with graphics, audio, video and images, where the removal of some data bits doesn't really affect the file. 

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Image Capture

There are many ways to capture an image. This can be done by a camera, a scanner or photocopier, or could be done by screenshots or screen recording software. The highest quality image for capturing a moment would be taking a photo with a camera. This is because cameras are built for this purpose. To capture an image on the web, a screenshot can be taken so that the image can be captured digitally. Scanning is useful for capturing images of drawings or documents to then use on a computer. 

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Optimising

Optimising means to improve the quality and functionality for images. This makes it more efficient. There needs to be enough balance between the file size and the picture quality. You can optimise an image by either reducing the bit depth (number of colours) , reducing the resolution, and reducing the dimensions.

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Storage of Image Assets

This is where the files created are organised in folders by file type and file size. For eg: Files that were are a model in a game would be put into one folder. This could include textures, photographs etc. 

In the game industry, this would allow the person who is supposed to do the shading on the model access all the assets for that model without any problems. 

  

Unit 78- Digital Graphics for Computer Games: What is a Pixel?

What is a Pixel?

AIMS: Understand the theory and application of Digital Graphics used for computer games.

A pixel is a small basic unit of programmable colour that is on an image or on a computer display. Each pixel has 3 different lights: red, green, and blue (RGB). These lights 'light-up' in a particular order and all vary in brightness. This means that if the pixel should be purple, then only the  blue and red lights will need to be lit and each light will vary in brightness to get that particular colour.  The naked eye should then see the pixel as purple because of  our viewing distance. This means that each pixel should be able to generate 16,777,216 colour variations for a 24 bit system because the system uses all 3 bytes of data (RGB value for each light). However, many displays use only one byte of data so only 256 colours can be created.

SOURCE: http://whatis.techtarget.com/definition/pixel

This is an image representation that shows the pixel arrangement in an LCD television. Each sequence of Blue, Red, and Green bars represent 1 pixel. 

IMAGE SOURCE: https://en.wikipedia.org/wiki/LCD_television

Image resolution is the detail a pixel can hold. If the image resolution is 1080 x 1080, this means that there must be 1080 pixels going across the screen, and 1080 pixels going up the screen. Therefore, the pixels must be small so the detail of the image will be greater. 

The size of the pixels depends on the resolution of the display or image. If an image or display is set to the maximum resolution, the size of the pixel will be the same as the dot size. However, if the resolution is less than the maximum resolution, the pixel will be larger than the screens dot therefore will use more than one dot. This is known as dpi (dots per inch) 

If an image has 72 dpi (dots per inch) the image would look good on a computer monitor, however when printed images would look blurry or pixelated. But if an image has 125 dpi, this means that the image will look good on the computer monitor and will also look good when printed. This is shown in the image below.

SOURCE: http://whatis.techtarget.com/definition/pixel

IMAGE SOURCE: https://lcexhibits.com/artwork-2/

To maintain the best quality of the photo when printing, professional photo paper should be used so that the image is transferred better when printing. This would be better than using cheap photo paper costing around £2 because professional photo paper will be manufactured so that ink absorption is greater. 

As well using better photo paper, 6 ink cartridges should be used so that each pixel can be printed closer to the colours on the display. This allows more colour variations than just a standard single CMYK cartridge.