How to Vectorize an Image

Updated Sep 21, 2021
Vectorize an image - raster image with vector image overlaid

Anyone working with CAD knows that learning how to vectorize an image can make your life so much easier. Whether you’re designing, sharing or editing an image, vector file formats are (more often than not) going to be the best option to ensure your work is the best it can be. With this in mind, we’ve put together a handy guide that covers everything you could possibly need to know about vectorizing images.

Table of Contents

What is vectorization?

Vectorization refers to the process of converting an image to a vector format. While raster files are made up of pixels, vector images are made up of a collection of individual objects. These objects may be in the form of arcs, lines, text, etc. Each one is defined by a mathematical equation. This means that even if you zoom in on the image or re-scale it, the quality will not be compromised.

The same cannot be said for raster files. Zooming in or resizing an image stored in a raster format will result in pixelation—thus, the quality will suffer. As a result of these kinds of drawbacks, people looking to create, share and edit designs with CAD software will need to vectorize their raster images.

Common vector formats


DXF icon DXF is a vector file format developed by Autodesk. It was created with the intention of allowing users to share their designs between multiple CAD programs. This explains its full title: Design eXchange Format. DXF is an open source format, which means that developers can include support for it in their software without having to pay for licensing. This has the effect of making the sharing process easier. Even if you’re working with AutoCAD drawings, for example, other people do not necessarily need to have Autodesk software to access them (which can be an issue with some other vector file types).

Thanks to these benefits, DXF has become the standard file format for data exchange within CAD. Industries across the globe are able to successfully collaborate on projects without being restricted to a single type of CAD software. We highly recommend using DXF files if you’re looking to be able to share your designs.


DWG icon DWG is a file format that was also developed by Autodesk. Initially created in the late 1970s, DWG was included alongside DXF from the very first version of AutoCAD in 1982. So, what makes it different? Well, DWG is the native file format for AutoCAD. DWG files are designed to be used with this specific software in mind and should enable you to get the most out of all of its features. This file format is therefore a great option if you work primarily with AutoCAD.

DWG stand for ‘drawing‘, with both 2D and 3D images being supported. As you can probably guess, the downside to this file type is that not all programs (especially those not made by Autodesk) will be able to access DWG files. It’s still not the end of the world if you find yourself needing to open DWG files and you don’t have the native software. While you might not be able to edit the images, there are ways you can at least view DWG files without AutoCAD.


SVG logoStanding for Scalable Vector Graphics, this vector format is—you guessed it!—particularly useful if you’re going to be re-scaling your designs.

What separates SVG from other vector files, like DXF and DWG, is the fact that SVGs are suited primarily for use on the web, rather than with CAD. Practically all web browsers support this format. Plus, it’s easy to embed SVG images into web pages, making them a great replacement for raster images in this realm.

Why vectorize an image?

Raster vs vector

Raster versus Vector Banner
While raster and vector formats can both be useful in their own ways, vector images are a necessary choice if you’re looking to use your designs in a CAD context. We’ve already touched on the quality issues that come with re-scaling images that are a collection of pixels—and that’s not where the issues end.

Raster images need to store color information for every single pixel, resulting in the file sizes being fairly hefty. This isn’t ideal in terms of computer storage. You also might not be very popular with the colleagues you share designs with, as you’ll be forcing them to download large files.

Raster images can still be of a high quality and are useful for those working in roles involving digital photography or web design. Additionally, despite their large size, most standard image editing software supports raster files, so they can be useful for sharing and storing images. However, if you need to edit individual elements within your image, or make it compatible with CNC software, vectorization is the way to go.

Common raster formats

Common raster formats
  • JPEG/JPG: JPEGs are named after the organisation that created them—the Joint Photographics Expert Group. You are likely to have come across this file type plenty of times, as they are commonly used to share photographs. They are fairly small in size, meaning digital cameras can store them without using up too much memory.
  • GIF: GIFs (Graphics Interface Format) have become wildly popular on the internet. Often used for web graphics, they also support animated images (which is what many people think of when they hear the word ‘GIF’). They are easy to share and supported by a wide range of software.
  • PNG: One of the most popular raster file types, Portable Network Graphics are commonly used for web graphics. They sit in something of a ‘sweet spot’, offering good quality graphics due to lossless compression, with smaller file sizes than TIFF or BMP files. This has made them popular online, while also meaning that they may, in certain circumstances, be suitable for vectorization.
  • TIFF: Short for Tagged Image File Format, TIFF is the top choice for those working in industries like photography and publishing. TIFF files are also the ideal choice for vectorization due to the very high image quality they support. This high quality comes with the downside, however, that TIFF files tend to be very large in size.

For use with CAD

The major advantage to vectorizing an image is that they can then be easily edited with CAD or CNC software. Remember those individual elements we referred to earlier? Well, each one can be recognized by CAD software and edited separately. This means that, whether you’re dealing with lines, paths or curves, each can be tweaked without making changes to the rest of the image. Every object is designated its own mathematical formula, allowing for a significant level of precision in the editing process.

As we’ve already mentioned, while you’re editing a design, you can zoom in and out of the image to your heart’s content, without the overall quality being affected. This is not the case with raster images—designs cannot be edited pixel by pixel and zooming or rescaling can leave you looking at a blurry image. As a result, if you’re looking to use your images in CAD, vector formats are certainly the way to go.

How does vectorization work?

In order to vectorize an image, the original raster version must be traced. This can be done either manually (by hand), or automatically (by a computer).

Let’s look at the pros and cons of each option…

Manual tracing

Image of a manually traced letter Manual tracing is exactly what it sounds like—physically drawing vector elements over the raster image. This is usually achieved using either a graphics pen or computer mouse. You will need to possess both basic drawing skills and a lot of patience to complete this task. If that sounds doable, there are certain benefits to this approach.

Carrying out the tracing yourself means you can closely control the entire process. Computers might be very clever, but they are yet to be able to recognise small details in images as accurately as the human eye. Doing it yourself is therefore the better option if your image is low quality, as you’ll be able to pick up details that may be missed by vectorization software. Converting an image through manual tracing can also be an interesting (if you’re a design enthusiast) and rewarding journey. You’ll be improving your skills and no doubt learning new things along the way.

On the other hand, be careful not to be too ambitious. Unless you’re a professional tracer, the manual approach should only be attempted if the image you’re working with is fairly simple. Otherwise, vectorizing the image could turn out to be an incredibly time-consuming and burdensome task. Be prepared for what you’re setting yourself up for!

Automatic tracing

If you don’t fancy doing all the work yourself, there’s a range of software out there that can automatically trace the image for you. Once your work has been opened with a conversion program, the technology is able to detect the features of your raster image and trace over them with vector entities. Thanks to constantly improving technology, many programs can now produce highly professional results in an amazingly short amount of time.

Automatically tracing a technical drawing floorpan using Scan2CAD

Automatically tracing a technical drawing floorplan using Scan2CAD

Take Scan2CAD, for example. Our software makes the conversion process quick and easy. Open your raster image in Scan2CAD, run vectorization and export the image to your chosen vector format.

In a matter of seconds you’ll have a professional vector image with which to work. To have a go at this yourself, download the free trial below.

Despite the obvious convenience of automatic tracing, you will need to make sure that your original raster image is appropriate and optimized for the conversion process. In other words, you should ‘clean‘ the image. 


Clean up for optimal results

Once you’ve decided to vectorize an image, there’s a couple of steps you need to take before actually starting the process. In order to achieve the best results possible, make sure your raster image is of a high quality before conversion. Ensure you do this even if you think your original image is fine—there are often flaws that you won’t notice at first glance.

Poor image quality for raster to vector conversion

Beware of these common image problems.

There are a few different steps you can take to clean up an image to make it suitable for conversion. These include altering the color depth, smoothing or thickening lines, and ensuring any holes are removed. For a thorough description of what each of these steps involve, and others you should take, consult Scan2CAD’s raster quality checklist.

Be aware that if your original image is broken, fuzzy, or contains overlaid information, it is unlikely to be suitable for vectorization. If you notice any of these features, select a new starting image before wasting any time attempting to vectorize.

Once your chosen image is as clean as you can make it, you’re good to go!


Now that you have professional standard vector images to play with, you can get to work making the most of your designs! But how to start? Well, when it comes to CAD, you have a wide range of software options. Consult the following table to learn more about some of the top names in the industry. 

CAD software options

CAD software compared
  • AutoCAD: Developed by Autodesk in 1982, this was one of the first CAD packages developed with PC use in mind. Boasting 3D capabilities, industry-specific toolsets and a vast number of customizable functions, AutoCAD is considered the staple CAD software by many in the industry. Be prepared to pay for all of these benefits, though—AutoCAD doesn’t come cheap!
  • CATIA: More than a CAD software, CATIA is actually a full PLM suite. Not only can you use it for designing and editing, CATIA also aids in the creation and production stages of your project. Thus, you can use this software to organise the entire life-cycle of your work.
  • SolidWorks: This 3D CAD application was one of the first in its field to introduce simulation capabilities. Users can design in engineering (rather than geometric) terms—making this software suitable for both professionals and amateurs.
  • DraftSight: This software has great options for those who just want to pay for the features they need. DraftSight is largely suited to those working with 2D images. Though it lacks industry-specific features, it’s well-suited to those for whom CAD is just a hobby. 
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