This document provides an overview of converting JPEG images to DXF files. It discusses that JPEGs are raster images made of pixels while DXFs are vector files composed of paths. Converting JPEG to DXF allows for easier editing and scaling of the image. The process involves tracing the raster image to create vector paths. Software like Scan2CAD can automate this through image recognition, though manual tracing provides more control. Common issues in the conversion include artifacts from JPEG compression and grayscale tones confusing the software. Proper preparation like thresholding can help optimize the raster image.

1. Ultimate Guide:
JPEG to DXF

2. Contents
What is a JPEG
file?.........................................................
3
What is a DXF
file?.........................................................
5
Why convert from JPEG to
DXF?...............................
7
How to convert from JPEG to
DXF...........................
11
How does the conversion process
work?................
14
Using Scan2CAD to convert from JPEG to
DXF....
17
Common problems with JPEG-to-DXF
conversion
21

3. What is a JPEG file?

4. What is a JPEG file?
JPEG (or JPG) is one of the most common file formats for
raster images. They are used for a wide range of
purposes, but are particularly popular for use in digital
photography.
JPEG files, like all raster images, are made up of pixels:
tiny, individually-colored squares. This means that they can
be used to display photo-realistic images, but it makes
them unsuitable for scaling.
JPEGs are known for having small file sizes. This is
achieved through the use of lossy compression. The gradual decrease in quality from
right to left is caused by JPEG’s lossy
compression.
Image credit: Michael Gäbler/AzaToth

5. What is a DXF file?

6. was created to facilitate collaboration between designers with different CAD
programs. As such, it is supported by virtually all CAD software on the market.
Like all vector files, DXFs are not made up of pixels. Instead, they are made
up of paths—straight or curved lines. A DXF file contains information about
these paths: where they begin and end; their color and width; and their degree
of curvature.
What is a DXF file?
DXF is a vector image file format used in CAD applications.
Alongside DWG, it was developed by Autodesk for use in
their CAD software, AutoCAD, which has since become
the most widely-used CAD program on the market.
Whilst DWG was intended to be used exclusively with
AutoCAD, DXF (which stands for Drawing Exchange
Format)

7. Why convert from JPEG
to DXF?

8. Why convert from JPEG to DXF?
Though JPEG is by far the more common of the two
formats, there are some major advantages to converting
your image to DXF.
Firstly, whilst JPEG files suffer from major degradation in
quality when they are edited, DXF files can be edited time
and time again with no loss in quality.
DXF files also maintain their quality when a user zooms
into and scales them. This stands in stark contrast to
JPEG files, which become heavily pixelated upon scaling.
...versus
zooming
into a JPEG
Zooming
into a
DXF…

9. JPEG files are made up of pixels, and so whenever you
zoom into a JPEG image, each individual pixel increases in
size. The grid of separate squares of color therefore
becomes obvious, and the image quickly degrades in
quality.
The paths that make up a DXF file work differently. When
you zoom in, the entire path increases in size, meaning
that the image maintains its quality at any scale.
An example can be seen in the images on the right: the
raster letter S becomes pixelated as it increases in scale;
the vector character, meanwhile, stays the same.
For more information, check out our article on Raster versus Vector.
Scaling a raster
image leaves it
pixelated...
...whilst vector
graphics retain
their quality.

10. A further advantage of DXF is that it’s easy to edit.
Individual elements in a DXF file can be separated out and
edited individually. Vector images make it easy to…
● change colors and line widths
● change the direction and length of a path
● edit text
● delete elements
DXFs typically contain clean lines and a very simple
range of colors, which makes them perfect for
architectural drafts, engineering drawings, graphic
design, logos, illustrations, sign making and more.
Unlike JPEG, however, DXF is not a suitable file type for
storing photo-realistic images.
Want to learn more? Check out our article on the
pros and cons of DXF.
DXFs are more suitable for line
art...
...whilst JPEG works better for
photos

11. How to convert
from JPEG to DXF

12. How to convert from JPEG to
DXF
Even though JPEG and DXF are both image files,
converting between them is an extremely complex process.
This is because there is no direct way to convert from raster
to vector. The only method is to trace over your raster
image with vector paths. This can either be done manually
or automatically.
Manual tracing is a good way of ensuring accuracy. It also
means that you have greater control over the finished vector
image. However, it can be extremely time-consuming—or,
if you choose to outsource the process, very costly.

13. Automatic tracing with programs such as
Scan2CAD can speed up the process
dramatically. While traditional manual
tracing of a raster image can take hours or
even days of work, Scan2CAD can convert
from raster to vector in just seconds.

14. How does the
conversion process work?

15. How does the conversion process
work?The basic principle behind raster-to-vector conversion is
image tracing. Since raster and vector images are so
differently composed, the only way to produce a vector
representation of a raster image is to trace over it.
In the past, images had to be traced manually. This
process is very time-consuming, often taking hours to
complete. Now, automatic image tracing enables images to
be converted within just a few seconds.
Automatic image tracing works by detecting patterns within
your raster image. It works to detect the lines, angles,
shapes, and edges within your raster image, and redraws
them as vector lines, polygons and curves.
Vectorization is a useful tool in the
field of architecture

16. Advanced conversion software, such as Scan2CAD, is also
able to recognise text within a raster image thanks to a
technology known as Optical Character Recognition, or
OCR. Using a database of the lines and angles which make
up each character, it detects the text present in a raster
image and replaces it with vector text. It then reassembles
this text into logical strings, as shown in the images to the
right.
Visit our blog to learn more about how OCR works.
Converting text to vector with other
conversion programs…
…versus converting text to vector with
Scan2CAD.

17. Using Scan2CAD to convert
from JPEG to DXF

18. Using Scan2CAD to convert from JPEG to DXF
It’s easy to convert from JPEG to DXF with Scan2CAD. To
start off, simply open your JPEG file in Scan2CAD by going
to the File menu, then clicking on Raster > Load.
Before you convert, you may need to take some steps to
optimize your JPEG so that it is ready for conversion. This
includes smoothing lines, removing holes and speckles,
and deskewing your image. Scan2CAD’s complete raster
editing suite makes it easy to get your image in great
condition.
Tip: To make sure that your images are always up to
scratch, follow our Raster Quality Checklist every time you
convert.
With Scan2CAD, you
can smooth raster
lines…
…fill in holes, and much
more.

19. In order to deal with different types of raster images, Scan2CAD comes loaded with a range of
pre-programmed vectorization settings. These can all be selected using the Type menu.
These settings tell Scan2CAD’s conversion engine to focus on different aspects of an image.
For example, straight lines would be favoured when analyzing an architectural image, whilst
the software focuses on curves when analyzing a contour map.
The image to the left is made up of
straight lines, and suits Scan2CAD’s
architectural settings…
...whilst the image to the right is made up
of curves, and should be vectorized as a
contour map.

20. Once you’ve opened your image and selected your settings,
you’re just a couple of clicks away from a vector image!
● To convert raster lines and shapes, either click Run >
Vectorization, press F7, or click the button.
● To convert raster text, either click Run > OCR, press F6,
or click the button.
● To convert raster lines, shapes, and text all at once,
either click Run > All, press F8, or click the button.
Once your image has been converted from raster to vector, all
you need to do is save it as a DXF! Just go to the File menu,
click Vector > Save As… and select DXF from the drop down
menu.

21. Common problems with
JPEG-to-DXF conversion

22. Compression artifacts
JPEG files are compressed using lossy compression. This
means that they are typically very small in file size, but it also
means that the image loses quality.
JPEGs are often marked by compression artifacts. These are
the visible signs of the distortion caused by lossy compression.
These artifacts can include images appearing blurry,
undefined, and blocky.
This makes it hard for the vectorization software to detect the
edges in your image. As a result, your vectorized image is
unlikely to faithfully reflect your original raster image.
The above image has lost
much of its quality due to
artifacts left by JPEG’s lossy
compression.

23. Grayscale
Whilst many JPEG images may appear to be black and white,
this often isn’t the case. The lossy compression used by JPEG
can cause the boundaries between black and white areas of
your image to become blurred, resulting in various shades of
gray being produced instead.
Whilst this isn’t normally a problem when simply viewing an
image, it can have serious consequences during vectorization.
Software such as Scan2CAD needs to be able to detect the
outline of your image in order to successfully trace over it. If this
outline is blurred, it won’t be able to distinguish which shades of
gray form the image, and which are part of the background. As
a result, it won’t be able to produce a good-quality vector image.
Clear distinction
between black
and white (PNG)
No definition,
blurred edges,
grayscale
(JPEG)

24. Converting photos
Vectorization software is capable of producing great results, but
it can’t work miracles. You can’t simply load a photo of a house
into Scan2CAD and expect it to produce an architectural draft—
it’s just not possible.
Whilst it is possible to vectorize a photo, it’s important to be
realistic about what can and can’t be achieved using automatic
tracing software. For more information, check out our article
covering how to convert photos to vector.

25. Other image quality issues
When scanning your image from paper, you may also end up with a number of other issues
affecting the quality of your image, including holes and speckles in your image, dithered and
broken lines, and hairy lines. These make it difficult for vectorization software to detect the
outlines in your raster image, and therefore to produce a high-quality vector image.

26. How to avoid JPEG-to-DXF
conversion problems

27. Don’t use JPEG
Whilst JPEG is one of the most common image formats around,
it is actually one of the worst formats to use for vectorization.
The lossy compression that JPEG employs to reduce file size
also has a serious negative impact on image quality. It leaves
images marked with compression artifacts. These can include
fuzzy edges, speckles, blocking and noise.
Since vectorization relies on clear lines and being able to
detect and trace over the edges in an image, this means that
most JPEGs are not suitable for vectorization. If possible, we
recommend saving your image as a TIFF or PNG image
instead.
Please note: if your image is already saved as a JPEG, its
quality will already have degraded, and this can’t be fixed by
changing its format.

28. On first glance, the GIF image on the left looks very similar to the JPEG in the centre. However,
upon closer inspection, the deficiencies of the JPEG format become clear. The background of
the image is not truly white, but rather varying shades of gray, blue, magenta, and yellow.
Meanwhile, the edges of the shape are not properly defined. This means that vectorization
software would have a hard time distinguishing the shape from the background, resulting in a
poor vector output.

29. Use thresholding
If your image is already saved as JPEG, don’t despair—there
are still steps you can take to optimize your image. The first of
these is thresholding.
One of the key problems with JPEG is that it does not handle
black and white images correctly, and treats them as grayscale
images. Thresholding helps to reverse this by dividing the
image into black and white pixels only.
Scan2CAD includes two types of thresholding—simple, which
is applied to the entire image, and adaptive, where the
threshold changes in different parts of the image. For most
images, simple thresholding will suffice.

30. How to use thresholding
Load your JPEG
image
1. Open the
thresholding tool by
selecting Threshold
> Simple from the
Raster Effects menu
2.
In the dialog that appears, use the slider to
control the threshold level, and the
preview window to check out the results
3.
Threshold
too low
Threshold
too high
Threshold
about right
4. When you’re satisfied with your image, just click OK and the threshold will be applied!

31. Clean up your image
Still struggling with hairy lines, speckles, and overlapping text?
Visit Scan2CAD’s Raster Quality Checklist to discover some of
the best ways to tackle these common problems.
Scan2CAD comes equipped with a full raster editing suite,
helping you optimize your image prior to vectorization. Then,
once your image is vectorized, you’ll be able to take advantage
of its vector editing capabilities. With this, you’ll be able to put a
final polish on your image, ensuring you get great results from
your vector conversion.
Want even more tips? Check out our Top 10 Raster Effects to
Optimize Your Vector Conversion.

32. www.scan2cad.com/blog
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tricks, be sure to
check out our blog!
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started with Scan2CAD!
www.scan2cad.com/blog

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