What Is Image Scaling?

Date First Published: 7th March 2024

Topic: Computer Systems

Subtopic: Computer Software

Article Type: Computer Terms & Definitions

Difficulty: Medium

Difficulty Level: 4/10

CONTENTS

Raster and Vector Graphic Scaling

Learn about what image scaling is in this article.

Image scaling is the process of resizing a digital image, either by making it smaller (scaling down) or making it larger (scaling up). Both vector and raster graphics can be scaled, but the processes are different. Image scaling is used in web browsers, image editors, image and file viewers, software magnifiers, digital zoom, thumbnail images, and when outputting images through screens or printers.

Raster and Vector Graphic Scaling

When scaling a raster graphic image, a new image with a higher or lower number of pixels must be generated. Scaling down a raster graphic may lead to visible quality loss since the pixels are squeezed into a smaller grid. A good image scaling algorithm will keep most of the image detail when scaling down an image. The further an image is scaled down, the less detail can be maintained.

Scaling up a raster image can also lead to visible quality loss. The image may become blurry and pixelated. The further an image is scaled up, the blurrer it will appear. In order to smooth out the edges, anti-aliasing is used, but a scaled-up image will not look as clear as the original image.

Vector graphics are much easier to scale than raster graphics. Images can be scaled up and scaled down easily without losing quality or becoming blurry. No matter how small or large they are, they always maintain their resolution. This is because they consist of points, paths, curves, geometric shapes, and mathematical relationships that connect them to create an image and have no fixed resolution.