Raster vs vector

It is the basics of any graphics software.

1. Raster vs Vector Made By: Suchitra Singh

2. There are two main type of image files : Raster Raster images are created with pixel-based programs or captured with a camera or scanner. They are more common in general such as jpg, gif, png and are widely used on the web . When using a raster program you paint an image and it's similar to dipping a brush in paint and painting. You can blend colors to soften the transition from one color to another. Vector Vector graphics are created with vector software and are common for images that will be applied onto a physical product. Also used in CAD, engineering, and 3D graphics. When using a vector program you draw the outline of shapes : and it's similar to creating an image with tiles of all different shapes and sizes. e.g. an eye shape, a nose shape, a lip shape. These shapes called objects display one single color each.

3. Pixels vs Vectors Raster images are made of pixels. A pixel is a single point or the smallest single element in a display device. If you zoom in to a raster image you may start to see a lot of little tiny squares. Vector images are mathematical calculations from one point to another that form lines and shapes. If you zoom into a vector graphic it will always look the same.

4. A raster image has a specific number of pixels. When you enlarge the image file without changing the number of pixels, the image will look blurry. When you enlarge the file by adding more pixels, the pixels are added randomly throughout the image, rarely producing good results. When you enlarge a vector graphic, the math formulas stay the same, rendering the same visual graphic no matter the size. Vector graphics can be scaled to any size without losing quality.

5. Comparison between Raster & Vector: Raster (Bitmap) Pixel-based. Raster programs best for editing photos and creating continuous tone images with soft color blends. Do not scale up optimally - Image must be created/scanned at the desired usage size or larger. Vector Mathematical calculations that form shapes. Vector programs best for creating logos, drawings and illustrations, technical drawings. For images that will be applied to physical products. Can be scaled to any size without losing quality.

6. Continue….. Raster (Bitmap) Large dimensions & detailed images equal large file size. It is more difficult to print raster images using a limited amount of spot colors. Some processes cannot use raster formats. Vector Resolution-independent: Can be printed at any size/resolution. A large dimension vector graphic maintains a small file size. Number of colors can be easily increased or reduced to adjust printing budget. Vector art can be used for many processes and easily rasterized to be used for all processes.

7. Continue….. Raster (Bitmap) Depending on the complexity of the image, conversion to vector may be time consuming. Raster images are the most common image format, including: jpg, gif, png , tif , bmp, psd , eps and pdfs originating from raster programs. Common raster programs: photo editing / paint programs such as Photoshop & Paint Shop, GIMP (free ). Vector Can be easily converted to raster. It is not the best format for continuous tone images with blends of color or to edit photographs. Common vector graphic file format: ai , cdr , svg , and eps & pdfs originating from vector programs. Common vector programs: drawing programs such as Illustrator, CorelDraw, Inkscape (free ).

8. DPI vs PPI DPI - Dots per Inch This is the amount of ink dots the printer will put on each pixel of your image. The DPI is set by the actual printer device and it is not something in the image for the graphic designer to manipulate . PPI - Pixels per Inch Digital raster images are measured in pixels, or picture elements. How many pixels per inch is determined by the device you create the digital image with: camera, scanner, or graphics software and can be modified with a photo/paint editing software.