- What is Raster? Raster, or bitmap images are the core standard format for photography and video. Most web graphics are bitmap based. Raster graphics can be contained in many different digital file formats such as JPG, GIF, PNG for the internet. For print we can use PSD, TIFF or PICT. Video formats could be a quicktime .mov file or a windows media file (WMV). Mpg and mp4 files are also bitmap based.
- Features of raster. Rastered images are great for displaying beautiful photographs or video, but they are "resolution dependent". This means that when a bitmap image is scaled up in physical size it will lose detail and quality. A bitmap image can have very high resolution, which means it has more pixels, this also results in larger file sizes and takes up more space on your hard drive.
- Raster aka bitmap. The images you see on your computer screen are made up of tiny pixels, look closely and you will see many little squares.... pull back and you can see the image. Each pixel has data that specifies its location and color. The more pixels an image file has the larger the file size is.
- What is vector? Vector is a formula, a mathematically based method for creating line data. It was popularized in manufacturing by Pierre Bezier who advanced the method to aid in automobile design and development.
- Features of vector. Vector files are scaleable, a vector image can be increased in size infinitely without losing image quality or detail. Because a vector image is based on mathematical formula the image file size is much smaller. Vector files aren't compatible with most internet browsers unless they are contained in an Adobe Flash file.
- Vector graphics. Because vector graphics are so powerful, all font file data is stored as bezier curves for crisp sharp printing no matter what size you create your text. Vector artwork is "resolution independent" so it looks great at any size.
- Can you guess? Ask students "Can you guess which of these images is vector and which is raster? (its a trick question, they are all raster).
- Surprise, it was a trick question. They were all vector art. A proficient vector artist can create photorealistic artwork, although it is time consuming.
- Recap: Vector is scaleable while bitmap is not (without losing quality). Bitmap is intended for photographs and video. Vector is intended for sharp crisp graphics, such as text.
Last modified: Tuesday, 26 June 2018, 10:44 AM