Aloy's

Comparing Bitmaps and Vectors

// February 7th, 2009 // No Comments » // trivia

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A bitmapped (or raster) image is an image made up of pixels – for example, a JPEG photo from a digital camera or a GIF image in a web page. Bitmapped images are great for storing real-world images, such as photos, that can’t easily be mathematically defined. The main disadvantages of bitmapped images are their large file size and the fact that they can’t be scaled well – if you enlarge a bitmapped image you quickly start seeing aliasing or, to use a technical term, “jaggy bits”.

In contrast, a vector image is defined mathematically using lines and curves. It’s not made up of pixels like a bitmapped image is. This means that vector images are resolution-independent; it doesn’t matter how big or small you scale a vector image, it never loses detail. Vectors are great for storing images that are easily described using lines and curves and that need to stay pin sharp at any resolution – for example: type, logos geometric shapes, and charts.

Excerpt from Photoshop CS3 Layers Bible, published by Wiley Publishing, Inc.