Vector images in Photoshop

One cool thing about vector images, also called object-oriented images, is that when you zoom in on them, they don’t look blocky. That’s because vector images are comprised of segments — curved or straight — and anchor points — elements that indicate the endpoints of the segments — that are defined by mathematical objects called vectors. Vectors use a unique mathematical formula to define the specific location of an object as well as its geometric shape.

Vector images are usually the product of drawing programs, such as Adobe Illustrator, but Photoshop is also capable of producing a vector or two. And not to be outdone, its cousin Illustrator can also rasterize (or convert into pixels) vector artwork, thereby providing you with raster images to work with.

Here is some additional information about vector graphics:
-->A curve is still a curve, even at 20,000 feet. Because they are mathematically defined, vector graphics can be sized and otherwise transformed without an inkling of quality loss.
Take that little 2-inch spot illustration and size it up to mural size, and it appears identical.
A perfect true curve remains a perfect true curve, whether it’s 2 inches or 20 feet long.

-->You can get pretty pictures in small packages. Vector images can be small in file size because the file size depends on the complexity of the vector objects, not the size of the illustration.

Graphics that need clean lines, such as logos, typographic illustrations, and line art, work great in vector format.

-->Vector images are independent — resolution independent, that is. Not only can they be transformed and printed without a degradation in quality, but they also have no built-in resolution — they take on the resolution of the output device. For example, print my logo in Figure 1-1 to an imagesetter (a high-end printing device used for color separations) at 2400 dots per inch (dpi), and the image comes out at 2400 dpi. Print it to a 300 dpi laser printer and what do you get? A 300 dpi image. (If all this technical lingo like imagesetter and dpi is confusing.

Because your monitor can display images only on a grid, vector images display on-screen as pixels. This accounts for the jagged appearance you see when you zoom into a curved vector object. But don’t worry; it will print just fine.