Bit Depth

Bit depth

Bit depth is sometimes called 'pixel depth' or 'colour depth'. Bit depth is the number of bits used to represent the colour of a single pixel. Bit depth also refers to the number of colours within a single pixel. 

BPP (Bits Per Pixel) refers to the number of bits in all three colour channels, this represents the number of colours available for each pixel. 

Monochrome palettes feature grey colours only, but grey from black to white, as both black and white are simply lighter and darker shades of grey. 

An 8-bit image will contain a palette of 256 colours in addition to raw image data. 

High Colour is a method of storing information on a computer using high colour graphics, this means that each pixel is represented by two bytes. 

True colour is needed to display an RGB (Red Green Blue) image. True colour features a 24 bit colour depth. 

Vector Images

Vector Images

Vector imaging is the use of lines, polygons, shapes and curves to represent images in computer graphics. Unlike JPEGS and other types of images, Vector images are not made up of a grid of pixels, Instead, vector graphics are made up of paths, which have a definitive start and end point. A path can be a line, a triangle, or a curvy shape. 

Because vector images aren't made up of dots, they can be scaled up to a larger size and not lose image quality, unlike if you scared up a raster image. This makes vector images ideal for logo's, which can be small enough to fit something such as a business card, or large enough to fill a large poster or billboard. Vector images usually consist of the following extensions: .AI .EPS .SVG .DRW

Raster Images

Raster Images

Most images on the internet are raster images, this means they are made up of grid pixels, referred to as bitmap. The larger the image, the more disk space the image will take up. Fortunately, image size can be compressed to make sure images don't take up as much memory. 

Image compression is basically the lowering of an images size and conversion into one of many different file types, such as JPEG or GIF. Image compression is used to save space by making sure images don't take up as much space when saved. When an image is compressed, the compression can be "lossy" or "lossless". A lossy compression is when an image loses a number of pixels while being compressed, and a lossless compression is the opposite, the image loses no pixels during compression. 

There are many different file extensions for images, for example, JPEG, GIF, TIF and BMP. There are more, but these are just examples. File extensions are just different types of image compression, and all basically squash the image into a smaller package to save more space. 

Pixel

Pixel

The word 'pixel' is short for 'picture element'. A pixel is a single point within a graphic image, images are shown on a display screen by showing thousands or millions of pixels, arranged by rows and collumns. When pixels are displayed on a screen, they are so close together they appear connected.

Image Resolution refers to the number of pixels in an image. Resolution can be identified by the height and width of an image as well as the total of pixels in the image. The more pixels within an image, the greater the quality of the image will appear. Image resolution is also about how close together the lines of pixels are within an image, as the closer together they are, the greater quality the image.

Pixel intensity is basically the brightness of certain pixels, which can variate throughout an image. You can find out the intensity of certain pixels in a specific area of an image using software such as Photoshop.