Research task-Pixel and Types of Digital Graphics

Research- Unit 78 Digital Graphics in Computer Games

Pixel-What is it?

Pixel

First of a pixel is not a square. The word pixel is a word made from "picture element"  If you've set the display to its maximum resolution, the physical size of a pixel will equal the physical size of the dot pitch (let's just call it the dot size) of the display. if you set the resolution large then the amount of pixels will increase.

Colour of the pixel

The specific colour that the pixel describes is some blend of three components of the colour spectrum. A true colour or 24-bit colour system uses all three bytes. However, many colour systems only use one byte.

                                                   Screen image sharpness

Screen image sharpness is often expressed as DPI, which stands for dots per inch. Dots per inch is determined by both the physical screen size and the resolution setting,  A given image will have lower resolution will have fewer dots per inch - on a larger screen as the same data is spread out over a larger physical area. On the same size screen, the image will have lower resolution if the resolution setting is made lower - resetting from 800 by 600 pixels to 640 by 480 means fewer dots per inch on the screen and an image that is less sharp.

Types of Digital Graphics

Raster Images

Tiff

TIFF stands for Tagged Image File Format. TIFF images create very large file sizes,TIFF images are uncompressed and therefor contain a lot of detailed image data which is why the files are so big. TIFFs are also extremely flexible with colour they can be grayscale, CMYK for print, or RGB for the web. TIFF is the most common file type used in photo software such as Photoshop, as well as page layout software such as Quark and InDesign, again because a TIFF contains a lot of image data to then let the user create a better image.

                                                        JPEG

JPEG stands for Joint Photographic Experts Group, JPEG files are images that have been compressed to store a lot of information in a small-size file.  Most digital cameras store photos in JPEG format, because then you can take more photos on one camera card than you can with other formats, this makes JPEG is a very handy file type to use

GIF

GIF stands for Graphic Interchange Format. This format compresses images but, as different from JPEG, the compression is lossless no detail is lost in the compression, but the file can’t be made as small as a JPEG. GIFs also have an extremely limited colour range suitable for the web but not for printing. This format is never used for photography, because of the limited number of colours. GIFs can also be used for animations.

                                          PNG

PNG stands for Portable Network Graphics. It was created as an open format to replace GIF, because the patent for GIF was owned by one company and nobody else wanted to pay licensing fees. It also allows for a full range of colour and better compression. It’s used almost exclusively for web images, never for print images. For photographs, PNG is not as good as JPEG, because it creates a larger file. But for images with some text, or line art, it’s better, because the images look less “bitmappy.”

When you take a screenshot on your Mac, the resulting image is a PNG probably because most screenshots are a mix of images and text.

Raw Image

Raw image files contain data from a digital camera usually. The files are called raw because they haven’t been processed and therefore can’t be edited or printed yet. There are a lot of different raw formats each camera company often has its own proprietary format.

Raw files usually contain a vast amount of data that is uncompressed. Because of this, the size of a raw file is extremely large. Usually they are converted to TIFFs before editing and colour correcting.

http://www.ivanexpert.com/blog/2010/05/the-5-types-of-digital-image-files-tiff-jpeg-gif-png-and-raw-image-files-and-when-to-use-each-one/

Vector Images

PSD

PSD file is a layered image file used in Adobe PhotoShop. PSD, which stands for Photoshop Document, is the default format that Photoshop uses for saving data. PSD is a proprietary file that allows the user to work with the images' individual layers even after the file has been saved.

WMF

WMF is a file extension for a graphics file used with Microsoft Windows. WMF stands for Windows MetaFile. WMF files can contain both vector and bitmap image information.

WMF files were 16-bit when initially included with Windows 3.0. WMF files can be opened by Microsoft Word, PowerPoint or Publisher.

AI

Adobe Illustrator Artwork (AI) is a proprietary file format developed by Adobe Systems for representing single page vector based drawings in either the EPS or PDF formats. The .ai file name extension is used by Adobe Illustrator.The AI file format was originally a native format called PGF. PDF compatibility is achieved by embedding a complete copy of the PGF data within the saved PDF format file. This format is not related to.PGF

The same “dual path” approach as for PGF is used when saving EPS-compatible files in recent versions of Illustrator. Early versions of the AI file format are true EPS files with a restricted, compact syntax, with additional semantics represented by Illustrator-specific DSC comments that conform to DSC's Open Structuring Conventions. These files are identical to their corresponding Illustrator EPS counterparts, but with the EPS procsets (procedure sets) omitted from the file and instead externally referenced using Include directives.