Optimising

In order to maintain the quality of file sizes or an image, and keeping a balance on the quality, depending on the target destination. For example, the target destination is the where you wish to place your graphics, and so that you can apply the graphics to where you desire, you have to save the graphic to a certain type of file format. For instance, if you wish to have an image on your website, you will have to save the image to a 72dpi, and for the image to at the same quality in a leaflet, you have to change the dpi to a 300 resolution.

With bit depth you can change the amount, which will also change the size of the file it is saved in. If you were to optimise the bit depth it depends on where you want to store it, as if you were to include it on the internet, you would have to sacrifice either the quality of image or the speed of loading time. If you were to increase the bit depth then the image quality will be at a good standard but it would take a while for the internet to load the image on the website and vice versa.

Intend image output is how you create a graphic to be of a good quality and size, as well as being efficient. This is important as the file needs to be easily accessed, as it is the data that includes the information of the graphic output. Another aspect that changes the quality of image for your target destination is image dimensions, as the dimensions of the length and width of images can control the size of the image. Even though you are changing the size of the image, the amount of pixels remains the same making the size of the pixels larger too. This means that if the image is stretched and made larger than should be, this is when the image would appear pixelated. So for the best outcome a vector image would be best to include on your website as it will never pixelate due to it being made of shapes.

Image Capture

There are many different ways to capturing images, for example digital cameras. There are a few types of digital cameras, such as bridge, DSLR and compact, but they all provide a high quality image, that will come with a high resolution. Digital cameras also can vary the amount of storage you have, with SD cards, but can also hold more memory than a mobile phone. However, if an image has been taken by a camera that is disposable, they can be scanned for possible reason, such as to view on your computer screen.  The file size is the amount of data the file can hold, and it can hold bits, pixels and bytes, for example a file size that could save 8 BPP could save JPEGs.

Asset management is if any files or images etc. has importance to you, then “asset management monitors and maintains” these important files. This could be useful for companies that have vital information that they need to keep, so will use asset management to keep the files safe.

Colour space

When it comes to an image that is greyscale, it will only include the colours, grey, black and white, with the intensity of the black being the weakest and the colour white being the strongest. The difference between a binary image and a greyscale image is that there is no colour grey in a monochrome image. Even though greyscale includes one more colour, it is still used for copiers and printers.

When the colours red, blue and green are mixed they create a range of hues that “will be able to make any colour” (07268grum.wordpress.com.) Being a colour model, the RGB will be used on digital screens so that when a certain colour is required, it will be easy to deliver to the viewer.

The model that defines colour space is YUV with chrominance (UV), which is the colour component of the model, whereas the (Y) luminance determines the brightness. The purpose of YUV is to “encode” graphics such as images and videos of colour, in order to cover up errors, so that the user isn't aware. This would be used for TV’s so that the viewers wouldn't be able to pick up on any accidental errors, making this more beneficial to use for the broadcasting company as the problems won’t be visible to the viewers.

Originating from the RGB colour space, HSV (Hue, Saturation and Value) and all of them apply different inputs, for example, value is the brightness of the colour. The saturation determines the pureness or sharpness of the colour whereas, hue determines the shade of a colour, and these factors are able to be changed as they are mostly used in editing software, making it easier for the user to select the specific colour they desire.

Bit Depth

Bit Depth is the amount of bits that is used to determine the colour, or “colour component” (grum.wordpress.com) of a single pixel, which is otherwise known as BPP (Bits Per Pixel) when discussed as a pixel, but when referred to a certain colour component “it is known as Bits Per Sample (BPS).” When it comes to bit monochrome, black and white are the only colours that characterize a single pixel, and when an image is in monochrome it is other known as a Binary Image, due to the two colours. Monochrome images are most likely used for printers and fax machines etc. as the pixels in most digital screens always include colour, also they are usually stored in a bitmap format as a raster image, which means that the files are rather small.
High colour is where the image information allows pixels to include two bytes. There are different amounts of bits when it comes to high colour, for example 15 and 16 bit high colour, and the difference is 16 bit high colour has the colour green as their main colour due to the operators eye being more sensitive to the colour green. On the other hand 15 bit high colour uses blue, green and red, with one bit in another channel. 
There are overall “256 different intensity values for each primary colour” (cambridgeincolour.com), which works out to 8 bits per channel, which is usually used in digital cameras. The name for having 256 colours available in 8 BPP (Bits Per Pixel) is VGA, and is mostly used for JPEGs and TIFFs. When there are all of the three RGB colours and they all add up to 256, and due to having 8 bits per channel this is a true colour. Because of the amount of colours true colour is used in graphics or images being processed.

Vector Images

A Vector image never pixelates, and this is because it isn't “made up of a grid of pixels” (techterms.com.) Instead they consist of lines,points, polygons and curves, which help indicate images graphically. Vector images are used instead of raster images, like JPEGs, GIFs, TIFFs and BMP formats.

The way that Vectors uses lines and curves is that they are “connected by points” (absolutegraphix.co.uk), and once the points are connected up, they look like a whole shape. Vector Images are also made from polygons which make up the points, which are called “primitives,” this means that vector images are good for typography and images for advertising so that no matter what platform you view the image it will be clear and won’t pixelate, making it more professional.

The file extension that vector images come as are EPS (Encapsulated PostScript), which is a type of file that can include text as well images, that is created in Adobe Illustrator. Another type of file format that is produced in Adobe Illustrator is AI (Adobe Illustrator Artwork) and SVG (Scalable Vector Graphics.)

Raster Images

Raster Image

Raster images are all digital and are made from pixels in a grid formation, which are known as bitmaps, you will find these types of images anywhere on your computer, for example the images from the internet including your own images that you have imported to your computer. 

Bitmaps can be in either a compressed or uncompressed format, for example the JPG (a JPEG image) is a compressed format, which was compressed by using lossy compression. This means that the lossy compression removes certain information from the file, that isn't visible or changes the view of the image you are saving. 

A JPEG (Joint Photographic Experts Group) does this so that you can change the amount of loss of information and the file size you want to make your image, and can maintain a high quality image at any size you wish to save it as. 

There are other file extensions such as, BMP, which can be both lossy and lossless compressed, and GIF (Graphical Interchange File) uses lossless compression as a format so that all the information before compression is kept afterwards, making sure you keeping all of the original file. This is used mainly on the internet so that whilst it’s being stored the size of the file gets smaller, then when used it returns to its original file size and format. More examples of file extensions are, PNG (Potable Network Graphic), TIFF (Tagged Image File Format), and PSD (Adobe Photoshop Document.) 

Pixels

Picture element is the actual terminology for the word, pixel, which helps to deliver a picture on a screen, or on a printed document. Depending on the type of document you want to produce, whether digitally or printed, the amount of pixels will change the image resolution to create a clear image.

For example 72 DPI (dots per inch) are preferably used for a digital image, as it is a low resolution, whereas if it was to be printed, it would have to be 300 DPI so that it is clear and the picture elements aren't visible from the image, due to it being a higher resolution.  Pixels also change due to the intensity of them, which is the brightness of the pixel, the intensity increases as the pixel is brightened and this will modify the contrast and determine the monochrome colours, as the pixel intensifies, more of the colour white is shown, and as it darkens, the colour black is more present.