Are you trying to convert a file from the PNG to DWG file format? In this guide, we'll cover everything you need to know about this file conversion. There's a step-by-step guide, sample use cases and some handy tips!

1. This guide is brought to
you by Scan2CAD,
the market leading file
conversion and editing
software
Ultimate Guide:
PNG-to-DWG
conversion

2. Table of Contents
▪ Why convert PNG files to DWG?
▪ How to convert a PNG file to DWG
▪ What is a PNG file?
▪ What is a DWG file?
▪ Behind the scenes: How are PNG files converted to DWG?
▪ Using Scan2CAD to convert PNG to DWG files

3. You’d convert PNG files to DWG when…
….you want to edit individual elements within the image
Working with PNGs is much like painting with
actual paint – editing involves ‘painting over’
the original image. The image is made up of
pixels, instead of vector shapes. Editing it would
involve applying a filter or adjusting
brightness/contrast. Singling out a single element
to be edited is close to impossible.
Image source: http://vector-conversions.com/vectorizing/raster_vs_vector.html
In contrast, vector files, like DWG are much more
versatile. They allow you you to edit individual
elements within the image. You can change
colors, resize a particular object within the
drawing, move elements around, copy objects into
other drawings, and more. It is this versatility that
makes DWG vector files invaluable to CAD work.
PNG (raster image) DWG (vector image)

4. You’d convert PNG files to DWG when…
PNG-to-DXF conversion comes in
handy when you have a stack of hard-
copy images, or a folder full of PNG
images on your computer that you’d
like to digitize. Converting to
DXF allows you to reuse parts of
older drawings in modern formats.
For example, a group of architects
working together can reuse certain
drawing objects, like doors or windows
in new projects. They can also share
the floorplan with interior designers,
electricians, building contractors, and
others.
Vectors are also scalable, meaning
that you can resize a vector drawing
as many times as you wish, without
any loss in quality.
….you want to edit or reuse the image (or certain parts of the image)

5. You’d convert PNG files to DWG when…
….you want to transcribe the drawing into operable instructions
An artist designs signboards or sculptures
using the software that they know best, such
as Adobe Illustrator or Photoshop. This
design is then converted to a DWG file,
using applications like Scan2CAD.
Then, the design is sent off to a CNC cutting
machine vendor, who will manufacture the
actual product from the DWG drawing.
These machines use the vector files to
generate automatic cutting instructions.
CAD programs also allow you to bring your
PNG images to life in other ways. You can
upload CAD drawings into 3D modelling
software, or even create animations from
your converted files.
From sketch…
…to CNC

6. You have two options to convert PNG files to DWG:
Convert manually, by tracing the PNG
image with a Vector Pen tool
Convert automatically, using a PNG-to-
DWG file conversion program
By using the right file conversion software, you’ll
save precious hours of your workday
…compared to a one click process!Lots of fiddling about with pens and grab points…
 Simply load the file into the conversion
program, click a few buttons and voilà!
You’ll have to complete some post-
processing steps,
but it’s still much
faster than
drawing manually.
 You could manually draw vectors. This
could take hours, or even days! It’s also
extremely difficult to get an accurate
vector drawing using this approach.
OR

7. Once the PNG is converted into DWG, you can load the
drawing into almost any CAD program
The world is now your oyster, and there are all sorts of CAD tools in your arsenal.
 You can cut, copy and paste certain elements of an existing drawing.
 You can edit specific elements of the drawing, such as reshaping Bezier curves, stretching
vectors, converting lines to arcs, and more.
CAD software makes it easy to revise and edit drawings.
All sorts of
CAD editing
tools in your
arsenal!

8. From a scanned PNG image to CAD 3D rendering…
An architectural designer can scan a hard copy floorplan. Once it’s converted to DWG,
they can share it with an electrical engineer for wiring plans, a structural contractor for
structural renovations, a landscape designer, and anyone else who may be involved in
the project.
Scanned and saved as
PNG
Converted to DWG
format
Used to create a 3D
rendering

9. Table of Contents
▪ Why convert PNG files to DWG?
▪ How to convert a PNG file to DWG
▪ What is a PNG file?
▪ What is a DWG file?
▪ Behind the scenes: How are PNG files converted to DWG?
▪ Using Scan2CAD to convert PNG to DWG files

10. How to convert: A step-by-step guide (1/2)
The entire conversion process takes about ten clicks. Here are the steps to converting
a PNG file to DWG using Scan2CAD:
2. Select the conversion settings. In Scan2CAD, there
are pre-programmed vectorization settings to help
correctly identify the objects in your drawing. For
example, the “Architectural” option is designed to detect
straight lines and right angles.
1. Load the PNG file that
you’d like to convert.

11. How to convert: A step-by-step guide (2/2)
3. Click “Convert”. Almost immediately, you’ll
have a DWG file that you can load into another
CAD software. It’s always best to spend a few
minutes to thoroughly check your DWG file,
examine the outputs and clean it up as necessary.
4. Save the DWG file. Now,
you can edit the DWG file
with any supported CAD
software.

12. Expert Tips for Conversion (1/2)
Choose
the right
image
quality
1
Reduce
the
number
of colors
2
Simple photos work better for raster-to-vector conversion. For example, a
silhouette against a plain background is much easier to convert than a photo-
realistic image.
To do this, you can define the color of your canvas for “1-bit color
depth”, which supports only two colours. You can also reduce
colors using a thresholding tool.
VS
VS

13. Your goal is to minimize any speckles, noise, hairy lines – if you don’t
want it preserved in your vector image, you shouldn’t have it in the
raster. Secondly, you need to help the software out by feeding it
distinct objects to trace and convert to DWG format.
Here are some markers of poor image quality:
Clean up
the image
3
Expert Tips for Conversion (2/2)

14. Table of Contents
▪ Why convert PNG files to DWG?
▪ How to convert a PNG file to DWG
▪ What is a PNG file?
▪ What is a DWG file?
▪ Behind the scenes: How are PNG files converted to DWG?
▪ Using Scan2CAD to convert PNG to DWG files

15. What is PNG?
Image source: http://www.fortuneproducts.com/printing-services/
PNG is a raster image file
format. A raster image
stores image information in
small squares of color called
pixels.
PNG supports lossless
data compression, which
means that it does not lose
quality during editing.
1
2
In CAD, PNG is commonly used to capture a
screenshot of the CAD drawing whilst edits
are being made. This is because PNG
images are easily shareable.
3 Did you know?
▪ PNG is pronounced “ping”!
▪ The acronym stands for “PNG Not GIF”, to
oppose the patenting of GIF
4

16. Why use PNG files in conversion instead of JPEGs or GIFs?
JPEG GIF PNG
Small file size
Can display millions of
colors, making it great
for photographs
Lossy file format
Bad for logos, line art,
and wide areas of flat
color
Small file size
Supports animation
Supports fewer colors
(hence why it is often
used for logos)
Although not lossy, it
uses dither filters to
diffuse colors, altering
the image slightly
Lossless compression,
so no data loss
Allows transparent
backgrounds
Great if file size is not
an issue (e.g. in
raster-to-vector
conversion)

17. Image source: http://makeawebsitehub.com/image-formats-mega-cheat-sheets/
TIFF or Tagged Image File Format, is an image file format for
high quality graphics. It is the most popular format amongst
graphic artists, the publishing industry, and photographers –
anyone who regularly deals with image editing and manipulation.
TIFFs can either be compressed or decompressed using
lossless compression, helping you preserve every single detail
of your image. Hence, it is the preferred format when scanning
photographs and sketches for raster-to-vector conversion.
Of course, greater detail comes at the expense of file size. In
addition, TIFF is quite a complex file format, and as a result it is
less likely to be supported by more general applications such as
web browsers.
However, you should always choose TIFF over PNG

18. Table of Contents
▪ Why convert PNG files to DWG?
▪ How to convert a PNG file to DWG
▪ What is a PNG file?
▪ What is a DWG file?
▪ Behind the scenes: How are PNG files converted to DWG?
▪ Using Scan2CAD to convert PNG to DWG files

19. DWG is a vector graphic file format
Here’s a drawing of a house, saved as a DWG file.
DWG files store both 2D and 3D data, as well as a database of dimensional
data and metadata

20. What programs can I use to view and edit DWG files?
▪ AutoCAD
▪ Scan2CAD
▪ Some versions of Google Sketchup
▪ DraftSight
▪ IntelliCAD
▪ CorelCAD
To view and edit DWG files To view DWG files only
▪ A360 Viewer (online viewer)
▪ DWG TrueViewTM (online
viewer)
▪ AutoCAD 360 (mobile and
web app)

21. Table of Contents
▪ Why convert PNG files to DWG?
▪ How to convert a PNG file to DWG
▪ What is a PNG file?
▪ What is a DWG file?
▪ Behind the scenes: how are PNG files converted to DWG?
▪ Using Scan2CAD to convert PNG to DWG files

22. How does the software convert a PNG image to DXF?
Raster-to-vector conversion software
basically traces the raster image and
reproduces the drawing using
vector entities. It also allows you to
trace outlines, or retain information
pertaining to whether a line is solid or
hatched.
It includes algorithms that can:
▪ Detect image edges
▪ Recognize different types of lines;
angles at which the lines are joined;
different shapes; different colors
▪ Recognize text

23. In order to create the best quality vector image, the
software employs a few processing techniques…
▪ “gap jumping” fills in gaps in the scanned raster image, helping create unbroken vectors
▪ corner sharpening to capture right-angles
▪ line thickening
▪ removal of unwanted spots and speckles
To learn more, check out our article on how vectorization software converts images to
DWG.

24. The conversion software can also “read” text and
“type” it out into editable vector text
If a scanned document contains text, the text is
saved as a raster image. Hence, the file
conversion software has to regenerate the text
in the document using smart OCR (Optical
Character Recognition) technology. It’s the
same concept as tracing shapes and lines,
except that the OCR algorithm detects letters
and numbers.
Click here to learn more about OCR and how it
works

25. More about extracting text from PNG files
Each program that is capable of OCR will
treat text differently. Great ones save whole
phrases of text in a single layer – this
makes the text easily editable.
However, subpar conversion software may
split the string of text into separate
characters and jumble the positioning of the
text. This makes the text extremely difficult
to edit, as you can see in the second and
third images on the left.

26. Table of Contents
▪ Why convert PNG files to DWG?
▪ How to convert a PNG file to DWG
▪ What is a PNG file?
▪ What is a DWG file?
▪ Behind the scenes: How are PNG files converted to DWG?
▪ Using Scan2CAD to convert PNG to DWG files

27. Features offered by Scan2CAD
 Support for over 40 file formats including
DWG, DXF, SVG, PDF, TIFF, and more
 Full set of editing tools for both raster and
vector images
 Smart OCR to recognize and edit text
 Built-in vector recognition presets to
correctly identify shapes and line types
Raster-to-vector conversion
 Raster and vector viewing tools
 Command line
 Batch processing
 Flexible licensing
 Excellent support 24/7
Other features:

28. Scan2CAD is the market leading file conversion and
editing software
Download your free trial
Scan2CAD includes conversion tools, image editing and cleaning tools, smart OCR, full
PDF support, as well as vector recognition and editing. Click on the blue button to learn
more about Scan2CAD.

29. Text
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conversion and editing software.
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