Do you know the difference between a raster and vector file? This quick overview will help you differentiate for an improved design workflow.
With so many images to choose from online, it can be overwhelming to determine which
Being comfortable with the ins and outs of both formats and how they translate when exported is an essential skill for every designer.
Let’s get started.
If you surf the web, chances are you’ve seen a raster image. Raster, or bitmap, images consist of tiny squares called pixels. These pixels contain bits of color and, when combined, they build images. The more pixels in an image the higher the quality, and vice versa. When you zoom in on an image, the pixels become more apparent while the details of the image become blurry.
Notice how the edges of the
Obvious pixels make an image look unprofessional and unsightly. As a rule of thumb, it’s best to only downsize a raster image to avoid heavy pixelation.
Due to the abundance of pixels in a raster image, the file sizes can be substantial. An illustration with higher DPI (dots per inch) or PPI (pixels per inch) will be larger in size and data, which can be worrisome when there are limits to image storage or restrictions on uploaded file sizes.
Tip: You can quickly cut down file size by reducing the resolution to 72 PPI for online images.
Raster images are used in photography and digital applications. When you take a picture with
To edit these images, you need access to raster-based programs like
File Formats for Raster Images
Raster files are saved in various formats:
- .tiff (Tagged Image File Format)
- .psd (Adobe Photoshop Document)
- .pdf (Portable Document Format)
- .jpg (Joint Photographics Expert Group)
- .png (Portable Network Graphic)
- .gif (Graphics Interchange Format)
- .bmp (Bitmap Image File)
While all of these display pixels, each
Vectors use a different approach to image renderings. They’re made of paths and curves dictated by mathematical formulas. These paths and curves are produced exclusively through design softwares designed for vectors, like
Due to their algorithmic makeup, vectors are infinitely scalable, and remain smooth and crisp even when sized up to massive dimensions.
A vector image’s formulaic makeup keeps file sizes to a minimum in comparison to its raster counterparts. This comes in handy when there are restrictions to file sizes or image storage. While a vector image file has many advantages, there are compatibility issues when shared. You must have access to vector-based programs in order to edit the native files.
Programs such as
For example, you might use a logo on something as small as a
File Formats for Vector Images
Vector files can be saved or edited in these formats:
- .ai (Adobe Illustrator document)
- .eps (Encapsulated PostScript)
- .svg (Scalable Vector Graphic)
- .pdf (Portable Document Format; only when saved from vector programs)
When to Use Raster vs. Vector
Pros and Cons of Raster Graphics
Raster images are used in many situations, but they’re not the best for every instance. Learning to know when to use raster and when to use vector in specific applications is essential for every creative.
Since raster graphics are made up of square-shaped pixels, they’re best for displaying detailed photographs and subtle gradations in color. Because raster images are more readily available in various file formats, they’re more accessible and easy to view online.
The accessibility of these graphics make them more shareable online in multiple applications, especially on social media and through web image browsers.
While raster graphics are nice for showcasing detailed photographs and shareable images, they do not scale well. Enlarge a pixel-based photo online and you’ll start to see heavy pixelation, which can appear unprofessional to the user.
In addition, raster images can have large file sizes dependent on the amount of detail that image has. Open up a larger raster image and you’ll notice a hefty file size in comparison to a smaller sized raster image.
Knowing how to best optimize the quality of your graphic, while keeping its file size low, is a crucial skill for every creative.
Pros and Cons of Vector Graphics
On the other hand, vector graphics have their uses. Because vectors are made up of mathematical equations, they’re infinitely scalable and are ideal for
While vectors are ideal for scalable logos, typography, and design, they’re not ideal when displaying photographic images. Rather than being comprised of square-shaped pixels, vectors are made up of mathematical curves and lines, meaning vectors display visual information differently than raster images.
In the image above, the photograph is best seen in a raster format. The vector version of the image is much more simplified, as vector programs will visualize the graphic in groups of solid colors.
Converting Raster to Vector (and Vice Versa)
Knowing when to use which type of graphic is crucial. But, what do you do when you need to convert a raster graphic to a vector image, and a vector graphic to a raster?
Transferring Raster to Vector
Converting raster images to vector formats can be done, but in specific contexts. For example, converting a raster image to vector is best reserved for simplistic designs rather than
Adobe Illustrator Image Trace
Converting a raster image to vector in Adobe Illustrator is ideal if you have access to Creative Cloud. In the Illustrator program, open up a new file and then place the image onto an artboard using Shift + Command + P. From there, open up the Image Trace panel by going to Window > Image Trace.
In the Image Trace panel, set the Mode to Color and the Colors to the maximum amount, 30. Hit Trace to allow Illustrator to process the image.
Once the image has been processed, expand the result by going to Object > Expand. The raster image now has editable vector components.
Online Raster to Vector Converters
If you don’t have access to Adobe Illustrator and need a raster image converted over to vector, have no fear! There are several online converters at your disposal that’ll make the process as seamless as dragging and dropping an image.
Some resources include:
Transferring Vector to Raster
Converting vector graphics to raster file formats is something every designer needs to learn. In order to share vector designs to those without vector program access, converting the vector design into a readable raster format is essential.
Saving and exporting the vector design into a raster format is inherent in every vector editing program. For example, in Adobe Illustrator, you’ll go to File > Export > Export As and then convert the design as a JPG, PNG, or TIFF file.
Sharing your vector design in a raster format rather than a vector file ensures anyone can view the attached file.
Cover image via