Making Mountains Out of Internet Mole Hills
We have all found that perfect image or graphic online that would go great in our printing project. You download the image, and put it into your design software, then notice the image is too small. That’s an easy fix, just make it bigger. However, the larger you make it the more distorted and pixelated it becomes. How can you fix this? Let’s assume, at least for the sake of this discussion, the image you found online is not copyrighted or trademarked (using others intellectual property without permission is not advised). When downloading an image and using it to print, it is paramount to understand image’s size, resolution and format. These three things are key to getting it to look good and print properly.
Size is simple enough, it is the measurement of the width and height of the image. When viewing images online they may all look the same size on the web page, but when you download them they can vary greatly. When looking at an image you can hold the mouse over it and it will typically give you the size of the image. The larger the image you start with, the less you will have to expand it (makes sense). If you start with an image that fits on a postage stamp, and what to enlarge it to fit on a 24″x 36″ poster you are going to need to stretch that image quite a bit. The more you expand the image the more distorted it becomes until it is barely recognizable. Starting with a larger image will help, but if need to enlarge it another way to decrease pixelization is to use an image with higher resolution
Image resolution refers to the number of pixels(tiny squares of light that make up an image) in an image. Resolution is closely related to the size. If you move your mouse over an image you might see something like 600 x 600. This is size of the image measured in pixels. It is 600 pixels wide and 600 tall, this entire image is made up of 360,000 pixels. The more pixels in an image the higher the resolution. The higher the resolution, the better the image will look when enlarged. One thing to remember, if you have an image that has 360,000 pixels in it you will always have 360,000 pixels in it, you do not gain pixels as you enlarge the image. This means if you start out at 5″ x 5″ and would like it to 15″ x 15″ you can do that, but instead of having 14,400 pixels per square inch, you get 1,600. The image will not have the same clarity and detail as it did when it was smaller. Lines and images will start to look boxy. This is because each pixel is a square of color, and the more you enlarge an image or zoom in on it, the more apparent they become.
The way your image is formatted may be the most important factor when it comes to resizing it for your print project. You will either have a “Raster” image, GIF, JPEG, and PNG, are the most popular file formats, or a “Vector” image, EPS, SVG or AI file formats. Raster images are by far the most common type of image or graphic you will find online (it may take some digging to find vector graphics).
The difference between the two is how they are made. As we said earlier, raster images are made by using pixels,or squares of color. Vector images on the other hand are made by using points that are connected by lines. With vector it is kind of like connect the dots, each point is connected with a straight line. The benefit of using a vector graphic is that no matter how large or small you make the image it will look the same, this is because the lines will all grow or shrink equally in proportion to each other. With a raster image you are limited in the size you can make the image because you can’t add extra pixels, so the larger you make it the more distorted it becomes. The image above illustrates the difference, as you can see the vector graphic keeps its shape and clarity, where the raster graphic becomes distorted.
This works great when you are using man-made animated images, however there are drawbacks to vector graphics. The image below shows what it looks like to have a vector image of a real life photograph. When a raster image is sized correctly, and has a high enough resolution you can not match the image quality with vector, at least not for real life images anyway. Vector graphics and images will always have an animated synthetic look to them because they are man-made reproductions.
Things to Remember
What it really comes down to is this, if you are going to use a raster image then you need to make sure of a few of things. First, make sure you are using the correct size image for your project. Second, if you do need to resize the image and make it larger, make sure the resolution is high enough to support the increase in size. Third, if you need the image to be enlarged enough that it becomes distorted, using a vector image will solve this problem, because no matter the size vector graphics always look the same. If you have questions about raster or vector graphics a friendly graphic design team can help you out.