{Unit 51 Task 1

By Jessica Grundy

Raster graphics are digital images created or captured as a set of samples of a given space. E.g. scanning a photo. In computer graphics, a raster graphics image is a dot matrix data structure representing a generally rectangular grid of pixels, or points of colour, viewable via a monitor, paper, or other display medium. Raster images are stored in image files with varying formats. A raster graphic or image is made up of pixels. Pixels are small squares of information. In order to understand what a raster graphic is, imagine a large grid that is made up of many squares (pixels) of all the same size. If you put a different colour in each square and then, you back away from the grid, the individual squares blend together to make up a picture. This is a raster graphic or bitmap graphic. Raster graphics are wonderful for rich, full-colour images such as photographs. Raster graphics are rendered images on a pixel-by-pixel basis and they are fantastic when handling shading and gradients.

Raster Graphics

Raster graphics are great when creating rich and detailed images. Every pixel in a raster image can be a different colour therefore you can create a complex image with any kind of colour changes and variations.

Almost any program can work with a simple raster file. The most recognized application that handles raster graphics is Adobe Photoshop however there are also several other image editing software options out there for you to choose from.

Advantages

Raster images cannot be scaled up in size very well. If you do try to enlarge a raster image, it will look grainy and distorted. This is because raster images are created with a finite number of pixels. When you increase the size of a raster image, the image increases in size however, because there are no longer enough pixels to fill in this larger space, gaps are created between the pixels in the image. The photo editing software that you are using will try to fill these gaps the best they can however, the resulting image is often blurry.

Raster graphics files are often quite large. Raster graphics files contain all the information for every single pixel of the image that you are working with. Each of these pixels has an X and Y coordinate as well as colour information associated with it therefore raster graphics files tend to be very large. Also, because these raster images hold so much data, they may be slower to edit.

Raster graphics are not great for embroidery. Because raster images are based on square pixels, your embroidery may look like it has jagged edges. If you want to embroider an image with smoother edges, it is best to use vector graphics instead of raster graphics.

Disadvantages

Vector graphics are based on mathematical formulas. A vector graphic is made up of a series of small points that combine together to make lines and images. The most recognized applications which handle vector based graphics are Adobe illustrator, Macromedia freehand and Corel draw. Vector graphics are generally used for line art, illustrations and embroidery. The term vector graphics is typically used only for 2D (planar) graphics objects, in order to distinguish them from 2D raster graphics, which are also very common. 3D graphics as commonly implemented today.

Vector Graphics

Vector files are small because they contain a lot less data than raster files.

Vector graphics are more flexible than raster graphics because they can be easily scaled up and down without any loss to the quality of the image.

Vector graphics have smoother lines when compared to square, pixel-based raster graphics therefore, they are better with straight lines and sweeping curves than raster graphics.

Advantages

If there are small errors or faults in a vector graphic, these will be seen when the vector image is enlarged significantly.

Vector graphics are generally filled with a solid colour or a gradient. They can’t display the lush colour depth of a raster graphic.

Disadvantages

JPG files, also known as JPEG files, are a common file format for digital photos and other digital graphics. When JPG files are saved, they use "lossy" compression, meaning image quality is lost as file size decreases. JPEG stands for Joint Photographic Experts Group, the committee that created the file type. JPG files have the file extension .jpg or .jpeg. They are the most common file type for images taken with digital cameras, and widely used for photos and other graphics used on websites.

Jpeg

The JPEG file format has been around for many years, and is support by every image editor and web browser on the market. It is also supported by every digital camera, and any video camcorder that can also take pictures. Every digital photo print shop also supports the JPEG standard.

Doesn’t take up much storage space.

Advantages

The compression algorithm is “lossy”, which means data is discarded when the file is compressed. For the most part, however, you won’t notice any loss of data – unless you start to edit the file.

The more compression you use, the more artefacts may appear. These usually look like “smudges” in the image, and can really reduce the quality of the image.

All the settings from the digital camera have already been applied to the JPEG. This can be a downside if, for example, you had the wrong colour balance set, then your digital pictures would have a colour cast to them.

Disadvantages

TIFF (Tag Image File Format) is a common format for exchanging raster graphics (bitmap) images between applications programs, including those used for scanner images. A TIFF file can be identified as a file with a ".tiff" or ".tif" file name suffix. The TIFF format was developed in 1986 by an industry committee chaired by the Aldus Corporation (now part of Adobe Software). Microsoft and Hewlett-Packard were among the contributors to the format. One of the most common graphic image formats, TIFF files are commonly used in desktop publishing, faxing, 3-D applications, and medical imaging applications.

Tagged image file format

No loss of image data. Free exchange between applications and

computer platforms.

Advantages

Difficult to store. Large file format.

Disadvantages

A 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. When an image is complete, Photoshop allows the user to flatten the layers and convert the flat image into a .JPG, .GIF, .TIFF or other non-proprietary file format so it can be shared. Once a PSD image has been flatten by conversion, however, it cannot be converted back to PSD and the user can no longer work with the image's layers. It is important, therefore, so always save the .PSD file and not overwrite it during conversion.

PSD

Can preserve layers. PSD files can handle simple vector layers, making them more suitable for importing and exporting data from programs like Adobe Illustrator. PSD also supports masks, colour profiles, alpha channels and spot colours.

PSD files’ large size and capability to save significant amounts of file information make them an excellent choice for working files.

Advantages

The PSD format is a proprietary Adobe file format. The company does not release its specifications to the general public. PSD support is often inconsistent outside of Adobe’s products.

PSD files tend to be extremely large, since these lossless images use no compression. This preserves all image information, but can make the file itself unwieldy and difficult to email or transfer.

Disadvantages

AI is a file extension for a vector graphics file format used in an Adobe Illustrator drawing. Adobe Illustrator is a popular vector graphics-based drawing program. The AI format is a strictly limited, highly simplified subset of EPS. AI stands for Adobe Illustrator.

AI

For advantages I was unfortunately unable to find some from Internet explorer.

Advantages

Along with Disadvantages, I was unable to find some for this file format.

Disadvantages

3DS is one of the file formats used by the Autodesk 3ds Max 3D modelling, animation and rendering software.

3DS

Unfortunately I could not find any advantages for 3DS.

Advantages

I was also unfortunate enough to not be able o find any disadvantages for this file format.

Disadvantages