Ultimate Guide: JPG-to-DWG Conversion

Updated Sep 19, 2017
Convert JPG to DWG

One of the most commonly used image file formats, JPG files are ubiquitous in the worlds of online graphics and digital photography. However, they also suffer from a number of limitations—some of which are common to all raster file types, some of which are unique to JPG. These make the file type unsuitable for use in fields such as architecture and engineering, where precision is key.

To help solve these issues, users can convert from JPG to DWG. As the native file format for AutoCAD, and one of the most popular vector image types on the market, choosing to convert your file to DWG means your image will not only be easier to edit, but that you can work on it collaboratively.

This handy article and slideshow will aim to answer all of your JPG-to-DWG conversion questions, and provide a comprehensive, step-by-step guide to the process. The best part? You can do all of it completely free. Check out our useful slideshow, or read our ultimate guide for all the details you need to know.

Table of Contents

JPG iconWhat is a JPG file?

JPG (or JPEG) is one of the most well-known raster file formats. JPG files have a 24-bit color depth, and use lossy compression, which means that they are typically small in size. This makes them a good choice for digital photography, as a memory card can store images in JPG format than is possible with other formats.

However, lossy compression also means that JPG images degrade in quality when edited. They are particularly badly suited to images with sharp, defined edges—including architectural or engineering drawings.

In addition to these JPG-specific problems, they also suffer from issues that are common to all raster images. For example, it’s impossible to scale or zoom into a JPG file without losing definition, and there is no way to edit individual elements within the image.

DWG icon What is a DWG file?

With a history stretching back almost 4 decades, DWG (or Drawing) files have become ubiquitous across the CAD industry. Best known as the native file type for AutoCAD, you can now view and edit DWG files using a wide range of programs—including Scan2CAD.

Unlike JPG, DWG is a vector file type, which means that it is made up of paths (straight or curved lines) rather than pixels. DWG files are infinitely scalable and easy to edit. This makes DWG a suitable format for storing technical design data.

DWG is a versatile format: it can store 2D and 3D data, vector entities, maps, and even photos. Essentially, any information you enter into a CAD program can be stored in a DWG.

CAD software to view and edit DWG files

A range of programs that can be used to view and edit DWG files

Why convert from JPG to DWG?

  • To digitize a hard copy of a drawing: you can scan a drawing (e.g. electrical/architectural plans) into Scan2CAD and then convert it to a DWG to begin editing it in a CAD application.
  • For infinite scaling: JPGs, like other raster file types, are made up of pixels, which makes them resolution-dependent. This means that you can’t scale a JPG without a loss in quality. In contrast, DWGs are made up of paths, which are mathematically defined and can be replicated at practically any scale.
    Check out our article covering the differences between raster and vector images for the full details.
  • For editing: working with a raster image is a little like painting: you can blend colors to create gradients and transitions, but you can’t edit specific elements of your image—any edits you make will affect the image as a whole. Vector images are completely different: you can easily edit individual vector paths, including changing their color, thickness and position. It’s also easy to copy elements from one DWG file and reuse them in another.


How to convert from JPG to DWG

There are two options for converting a JPG image to DWG: 

Manual tracing

Traditionally, the only way to produce a vector representation of a raster image was to manually trace over the image with vector lines. This involves creating a new vector layer on top of the existing image, then tracing over the lines by hand using a mouse or graphics pen.

This method is still useful, as a human looking at an image will understand what it represents. A computer program, meanwhile, is only able to work off the lines and edges it detects. This means that you can manually trace any image, regardless of its quality. However, the process is extremely time-consuming. As a result, many designers prefer to use a faster solution.

Automatic conversion

When you convert your JPG image automatically, your chosen software will work to detect the lines and edges present in your raster image. It will then redraw these as vector lines, curves, polygons, and other vector entities. Some advanced conversion programs, such as Scan2CAD, can also recognize raster text within an image using OCR (Optical Character Recognition) tools before redrawing it as vector text.

The downside to automatic conversion is that a program can never have the same understanding of an image as the person who created it. The image must be very clear for the process to work well, and the user will still need to undertake some pre- and post-processing work. Nevertheless, automatic tracing can reduce conversion times from hours to just seconds, and can produce great results.

Animation Converting Image in Scan2CAD

Automatic Tracing: Converting an architectural drawing to a vector CAD format in Scan2CAD

For more information, check out our article covering the differences between manual and automatic tracing, or take a better look at the process by learning how to automatically trace an image.

Why you should avoid online conversion tools

It might be tempting to simply opt for an online tool to convert from JPG to DWG. After all, they often promise to convert your file fast, with no downloads. But before long, you’ll notice some problems.

First, online converters have strict limits, meaning that you can only convert a small number of files—forget about converting anything with a large file size.

Then, when you actually convert your image, you notice that the result is subpar. Instead of the full range of vector entities, some online converters simply use colored polygons to represent sections of color within your image. Most would have a hard time converting raster text to editable vector text—and even those that can are unlikely to arrange that text into logical strings.

On the left is text converted using Scan2CAD. On the right, you can see an example of text that has been improperly assembled into strings.

Worst of all, choosing an online converter means running a number of security risks. Not only is there the danger of someone else stealing your intellectual property, but you could end up inadvertently downloading viruses or trojans onto your system.

Choosing Scan2CAD means keeping your files safe and secure. As it runs locally, it can offer far more precise and efficient conversions than any online converter—with no restrictions on file size, and the ability to process multiple files at once.

Problems with JPG to DWG conversion

Whilst automatic tracing can dramatically speed up your conversion, it requires a high-quality image to work successfully. Unfortunately, JPG images can suffer from a number of issues which can hamper your chances of getting optimal vectorization results. Some of the most common problems can be seen in the image below: 

Poor image quality for raster to vector conversion

Other problems with JPG images include: 

  • Trying to convert the wrong type of image. Whilst automatic tracing is incredibly useful for many kinds of image, it’s important to be realistic about what you can and can’t do using vectorization software. Photos, for example, are not well-suited to conversion. Good candidates for conversion are synthetic images with few colors and clean lines. These include images such as technical drawingslogos and cartoons.
  • Compression artifacts. Since JPG files are compressed using lossy compression, they lose quality when edited and saved. This leaves compression artifacts on the image, which are the visible signs of the distortion caused by lossy compression. They make the image appear blurry and undefined. These artifacts make it difficult for the software to detect the lines of the image, making it harder to convert.
  • Black and white images being saved in grayscale. The most common use of vectorization software is to convert technical drawings, which tend to be black and white. JPG does not deal well with these images, as it is created to deal with photo-realistic images featuring color blends. As a result, JPG will often try to soften the contrast between the foreground and background, leaving the image blurry, with many shades of gray. As a result, conversion software finds it harder to detect which parts of the image form the foreground and background, making it very difficult to convert.

Failing to address these issues prior to conversion means that your vector output is unlikely to be of a high standard. Luckily, there are some helpful tips you can use to optimize your raster image and improve your conversion results.

How to get the best results

  • Use a better format than JPG. The simplest way to avoid the problems associated with the JPG format is to save your raster image in another format in the first place. As we’ve previously noted, JPG is not a suitable format for drawingstext or solid graphics. For optimal conversion results, Scan2CAD recommends saving your raster image as a TIFF. TIFF offers lossless compression and high resolution, making it perfect for vectorization.

    However, sometimes, the choice of file format might be out of your hands—for example, if a colleague had sent you a JPG image to work with. In this situation, you can take additional steps to improve the quality of your JPG file, and get better vectorization results.

  • Scan2CAD offers thresholding tools, enabling you to divide your image cleanly into black and white pixels, eliminating the issues caused by grayscale images and compression artifacts. There are two available thresholding tools in Scan2CAD:
    • Simple thresholding, which applies the same thresholding settings to the entire image, or
    • Adaptive thresholding, which applies different thresholding settings to different parts of your JPG file.
  • For most images, simple thresholding should suffice. To access thresholding tools, click on the Load menu, then click Raster Effects Threshold , and choose either Simple or Adaptive.
  • You can also take advantage of Scan2CAD’s range of cleaning tools. These can help combat many of the issues affecting JPG images, including:
    • Fix broken or dithered lines using thicken lines
    • Remove holes or speckles
    • Use the smooth tool to remove rough or “hairy” edges around lines
  • For best results, check out our top 10 raster effects to optimize your vector conversion.

Raster to Vector Image Conversion - Clean and Edit Image Tools

Even if you think your image is perfect, you may still miss some hidden issues which could affect the quality of your conversion. Make sure to follow our Raster Quality Checklist for best results every time.

Using Scan2CAD to convert JPG to DWG

Think it takes hours to convert from JPG to DWG? Think again. With Scan2CAD, the conversion process takes seconds—and it couldn’t be simpler. Plus, you don’t have to worry about being given a generalized conversion. 

Scan2CAD detects the lines and edges in your raster image and redraws them as vector entities such as: lines, polygons and Bezier curves. It also looks at factors like the angle of the curves and line weights. Using pre-programmed variables and vectorization settings, Scan2CAD is able to give you a unique conversion depending on your type of image. For example, if you’re converting an architectural drawing then Scan2CAD will use different settings than if you were converting a contour map. And as we’ve mentioned before, the entire process takes mere seconds to complete!  

Need to convert a different file format? Click here to learn about converting from PDF to DWG.

Features offered by Scan2CAD

scan2cad product box Scan2CAD’s primary focus is the conversion of technical drawings—such as engineering drawings, architectural drafts, and site plans—to usable and editable vector images.

In addition to its innovative conversion tools, it also comes complete with an extensive raster and vector editing suite, so you can fully optimize your image before and after conversion.

It supports no fewer than 33 file types, and offers market-leading OCR software. With batch processing, flexible licensing and 24/7 support, Scan2CAD is the complete package.

Interested in converting from JPG to DWG? Try out Scan2CAD’s free 14-day trial and make use of its full range of professional features—with no watermarks, no limits, and no obligations.

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