Inkscape/C4/Trace-bitmaps-in-Inkscape/English

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Title of script: Trace bitmap in Inkscape

Author: Arthi and Shital

Keywords: Difference between raster and vector image, various raster and vector formats, convert raster image to vector


Visual cue
Narration
Opening Slide Welcome to the Spoken Tutorial on “Trace bitmap in Inkscape” using Inkscape.
Learning Objectives (Slide) In this tutorial

We will learn the

  • Difference between raster and vector image
  • Various raster and vector formats
  • Convert raster image to vector
System requirement (Slide) To record this tutorial, I am using
  • Ubuntu Linux 12.04 OS
  • Inkscape version 0.91


Show the images The images used as examples in this tutorial, have been provided in the Code Files link.

Pause the tutorial here and download the images on your machine.

Show the images Here are the 2 images on my desktop.
Point to the images Linux.png is the raster image and Linux.pdf is the vector image.


Let me open them.

Zoom into both the images Both the images may look similar.

We will know the difference only by zooming into the image. Let's do so.

Point to the first image Now, the first image looks pixelated because a raster image is made of up pixels.
Point to the second image But the second image does not pixelate because a vector image is made up of paths.
Raster image formats (Slide) Some of the raster image formats are
  • JPEG
  • PNG
  • TIFF
  • GIF
  • BMPetc


Vector image formats (Slide) Some of the vector image formats are
  • SVG
  • AI
  • CGM etc


Compound formats The formats that can be both vector and raster are
  • PDF
  • EPS
  • SWF

<<PAUSE>>

Point to both the images Let us now learn how to convert this raster image to vector.
Open Inkscape Open Inkscape.

Now, we will import the raster image.

Go to File >> Import Go to File and click on Import.
Path menu >> Trace Bitmap Now, go to Path menu and click on Trace Bitmap.
Point to the dialog box A dialog box opens up. Under the Mode tab we can see various options.
Point to the image Make sure the image is selected.
Point to the Brightness cutoff option By default, Brightness cutoff option is selected.

Under Preview, check the Live Preview option to observe the changes.

Point to Preview window As you can see in the Preview window, Brightness cutoff finds the difference in brightness.
Click on Edge detection Now click on the second option, that is Edge detection.

As the name indicates, it finds only the edges.

Click on Color quantization Color quantization traces along the boundaries of reduced colors.
Click on Invert image >> Uncheck Invert image will invert the colors of the bitmap if you think it looks better inverted.


I will uncheck the Invert image.

Click on Multiple scans Multiple scans is good for multiple colors.
Click on Brightness steps Once again Brightness steps finds the difference in brightness.
Click on Colors Colors finds an amount of colors specified.
Click on Grays >> Uncheck Smooth Grays is similar to Colors, but finds only grayscale colors.


Uncheck the Smooth option, since it creates more smooth lines in the edges.

Point to the dialog box Now we have seen all the tracing options.

You can choose from any of these according to your requirement.

Click on colors option I will choose Colors options by clicking on it.
Click on OK >> Close the dialog box Now click on OK and close the dialog box.
Point to the traced image The traced image in created on the top of the original image.
Click and move the image Click and move the image to one side in order to see both the images.
Zoom in to the images The image is now converted into vector.

Zoom in to the images.

Point to both the images As mentioned earlier
  • the first image gets pixelated,
  • while the second one does not gets pixelated.

And we can also see the paths very clearly.

Delete the original image Now, delete the original image.
Go to Path >> Break Apart Select the image. Go to Path. Click on Break Apart.
Double click >> Move images apart Now double click on the image. Stack of images are created on the top of the other.

Click and drag them aside to make it visible.

Select the images except black >> Delete Next let us learn how to edit the vector image. I will edit the black image.

So delete the other images.

Add nodes on the head area Make sure the image is selected.
Change the colors Go to Path. Click on Break Apart.
Fill and Stroke >> reduce opacity to 50 Under Fill and Stroke, reduce the opacity to 50.

Now you can see the parts clearly.

Change the colors of the image Next let us change the colors of the image.
Increase the opacity to 100 You can change the colors according to your imagination.

Now select all the parts and increase the opacity to 100.

Press Ctrl + G Press Ctrl + G to group them all together.
Select the image >> click on the Nodes tool. Now let us add some hair-style.

To do so, select the image and click on the Nodes tool.

Select the node >> drag upwards..... Do so for all the new nodes. Add nodes to the head area.

Now move the nodes a little up as demonstrated.

Point to the image Let me now save the image in both raster and vector formats.
Save the image as PNG First save it as raster, that is, in PNG format.

Go to File and then click on Save As.

PNG >> Image-vector Change the name as Image-raster. Click on Save.
Point to the image Next let us save the image as vector, that is, in PDF format.
File >> Save As Once again, go to File and click on Save As.
Save the image as PDF Change the extension to PDF

Change the name as Image-vector. Click on Save.

Open both the images Now let us go to the desktop and check both the images.
Point to both the images You can clearly identify the difference between the two images.
Summarize That's all for this tutorial. Let us summarize.

In this tutorial, we have learnt the

  • Difference between raster and vector image
  • Various raster and vector formats
  • Convert raster image to vector
Assignment As an assignment, select the train image which is given in your code files link and convert it to a vector in Grays.


Your completed assignment should like this.

About Slide The video available at the following link summarizes the Spoken Tutorial project. Please watch it.
About Slide The Spoken Tutorial Project Team conducts workshops and gives certificates for those who pass an online test.

For more details, please write to us.

About Slide Spoken Tutorial Project is supported by the NMEICT, MHRD, Government of India.

More information on this Mission is available at this link.

Acknowledgment We have come to the end of this tutorial.

This is Arthi and Shital from IIT Bombay, signing off. Thanks for joining.

Contributors and Content Editors

Arthi, Nancyvarkey