In this I will be answering frequently asked questions like, What are graphics? What are graphics used for? and How to create graphic material for Interactive media? I will be answering these questions and explaining the different types of graphic file extensions and much more!
Picture Element or Pixels as we commonly refer to, are the small dots that make up the imagery on our computer screens, tablets and phones. Pixel size may vary to the size of the screen; usually you can’t see individual pixels as they are really small and divide into a pool of millions of pixels. This brings us onto resolution, something like 640x480 is the most common, and this applies to the size of your screen and images 640x480 means a matrix of 640 by 480 pixels or 307,200 tiny little dots.
Each pixel contains a colour, due to the small size they blend together with other pixels to create different shades and blends of colours. The number of colours each pixel can be is determined by the number of bits used to represent it i.e. 8-bit colour is 2 to the 8th of colours to be displayed. At 8-bit you can see graininess, a good example of this would be the old Super Mario games on the Nintendo.
However there are other color depths i.e. 16, 24 and 32. These display the images in a smooth manner and the graininess is not visible to the human eye.
Blasting off into colour space!
There a different colour encodings used fir either print, computer display or television.
The different types are:
RGBThis stands for Red, Blue and Green and it is used for computer displays and is not ideal for printing as ti doesn't contain as many colours.
CMYK
This stands for Cyan, Magenta, Yellow and Black. This is the option specifically for printing, that's why the coloured ink in printers today are actually Cyan, Magenta, Yellow and black.
YUVThis encoding system is used for alalog televison i.e. NTSC and PAl. Y in the name represents luminance or in laymans terms brightness, while U and V are chrominance or colour components
Knee deep in bits
Bit depth decribes hte number of bits used to store a value, and the number of values grows with the number of bits.
This is an image representing pixels, millions of these are all over our screens.
Monochrome
This literally means once colour, therefore just like the name says, this can be an image that only has one colour but it may contain many shades. Monochrome graphics were used in the old computer screens before the ancient CRT screen, they used a shades of green for text and other icons.
Highcolour
This colour system supports three 16-bit RGB colours but there can be 4 bits with possible 16 levels fir each of the Red, Green and Blue components.
Master of Raster
Raster graphics are pictures that store a lot more information as they are raw, they are something you find ona digital camera or on most web-pages, they usually require more space to store the required information.
640 x 480 needs 307,200 pixels if information whilst a Raster images of 3072 x 2048 require a staggering 6,291,456 pixels of information. You can pretty much imagine how much space an image of that size would take up, to avoid the large use of data, we have file extensions to compress the large size to make it easier for us to use images for websites, graphics design and more. Although they can be compressed into manageable data, the images don't lose their quality, on the other hand when they are enlarged they become pixalated or blocky.
Quality loss?
Lossy is a type of file compression which loses data and quality form the original version. Lossy compression is known for image files such as JPEGs, the lossyness of an image can show various defects to an image i.e. pixelated areas, blockiness and jagged edges. A good example of this is JPEGs, compared to the original image the disk space it takes up is massively lower, but it loses some of it's quality in doing so, as it removes data.
Lossless imagery on the other hand, reduces the files size with no loss of quality at all, JPEG 2000 is usually used to create the lossless compression. Lossless compression rewrites data of the original file without changing it, resulting in no loss of quality, meaning no matter how much you resize it, it will stay the same.
The file extensions for raster images vary, here are some of the most common ones;
BMP
This is an uncompressed raster image, short for Bitmap, is commonly used in a raster graphic format for saving image files. A BMP format image stores data for each pixel colour in it, leaving it uncompressed allowing high-quality graphics and large file sizes.
PNG
Portable Network Graphics, otherwise know as PNG is a compressed Raster format, it can be found all around the web and it is also a popular choice for application graphics. Here's a fund fact, a PNG image can hold over 16 Million Colours, this is the biggest difference between PNG and it's compression cousin's, JPEG and GIF. PNG format also supports 24-bit colour, meaning although a PNG is compressed the quality is unrivalled.
GIF
This one's interesting, the full name being Graphics Interchange Format, you can pretty much guess what it does, if not let me explain! GIF is a compressed image format that is based on indexed colours, which is 256 maximum colours of the pallet. This means the size can be reduced great;y, meaning they can be easily transferred over the internet, one of the reasons why you often see GIF's on the web. As GIF's can be used for small icons and mainly animated images, which dominate today's social networking blogs. But compared to other format's, GIF's don't have the colour range for High-quality photos.
TIFF
Tiff stands for Tagged Image File Format, this format is designed to function on multiple computer systems and platforms, it has a ranged colour depth from 1-Bit to 24-Bit ever since being introduced in 1980. There are 50 variations of the TIFF format, although this was the most universal graphic format back in the day, right now JPEG dominated due to it's internet comparability.
JPEG
JPEG stands for Joint Photographic Experts Group, yes a very long name, but there is a reason behind it; it is the name of the committee that developed the format. JPEG is a compressed image file format that is not limited to a certain amount of colour, meaning this is the best compression format ,it is widely used across the web, any large image you may see on the internet, is most likely a JPEG.
Although can store a lot of High-resolution data, it is a lossy format meaning quality is lost when the image is compressed, once compressed it can become blocky with loss of detail.
Vector's blast off!
Vector graphics are a lot different compared to pixel orientated Raster compression formats like JPEGs, GIF'S and BMP, instead Vector graphics are made up with paths, defined by the start and end points along with other points, angles and curves along the way. A patth can be anything from a line to square, triangle etc. The paths can be used to create simple images to complex diagrams.
Since Vector-based graphics are not made up of pixels, they are lossless as they lose no quality at all when enlarged unlike Raster images, this makes Vector images more versitile for large printin, flash animations and Adobe illustrator works.
As well as Raster graphics, Vector graphics also have various extensions, these are:
EPS
Developed by Adobe and known as Encapulsated PostScript File, is a file that contains 2D vector graphics, bitmap images and text. EPS is supported by various drawing programs and Vector editing software.
AIThis is a file extension of a Vector editing program known as Adobe Illustrator, Illustrator images are saved in a Vector format, they can be blown up without the loss of quality.
SVGKnown as Scalable Vector Graphics file, SVG is developed by Adobe and it's used for 2D vector graphics, created by W3C (World Wide Web Censortium) developed as the format for wen images and text.
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