Nothing is worse than a fuzzy image. What’s the deal with resolution?
Merriam-Webster’s dictionary defines resolution as, “a measure of the sharpness of an image or of the fineness with which a device (as a video display, printer, or scanner) can produce or record such an image usually expressed as the total number or density of pixels in the image .”
Anyone with a Dad like mine knows the importance of a high-definition television – stuff just looks better when it’s a crisper image. This goes for printed materials as well as online and video. But ideal resolution means different things for different media. A good rule of thumb is to consider the “dpi” or “dots per inch”.
dpi is essentially the dot density – the number of individual dots that can fit in a line within the span of one inch.
Let’s back up. Graphics are made of dots. Much like those jigsaw puzzles where the image is made up of lots of little photos, all images files are made up of lots of little dots. The density of those dots is the dpi. Depending on the usage of the image file, the density (or dpi) can be higher or lower.
In traditional printed materials, the necessary dpi for high-resolution imagery is 300. That means that for every length of an inch 300 teeny tiny dots should fit in a line within that inch. For web images, the dpi can be much lower since most screens still only display 72 pixels-per-inch.
However! dpi really only matters for printed materials. When an image is going on the web, dpi is really measured in pixels. Pixels (or picture elements) are the smallest unit of measure for color on a screen. There are only two ways to enlarge an image – resizing it by stretching the existing pixels (causing the image to lose crispness) or bulking up the resolution by adding more pixels to the same space (thereby increasing the detail and providing a crisper image).
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The Beginner’s Guide to Graphics a four-part series. Read on to learn more!