Here’s my approach for how to turn 2D images into 3D models.
There are web apps that will do this for you, but my approach gives you a lot more control and may produce higher quality models.
Also, it only uses free and open source software. 😀
First we start with an image. I have here the logo of Julia, obtained from Wikipedia.
Open the image in Inkscape
Select the image and navigate to Path > Trace Bitmap
Adjust the Trace Bitmap settings. Trace Bitmap will turn your image into a vector. Update will show what the final output will look like. Hit OK to confirm changes.
Save the newly traced image as an SVG file.
Open Blender. Import the SVG using File > Import.
Your SVG will imported as a very small Curve object, so you’ll need to zoom in to see it.
Navigate to the Curve settings.
Adjust Extrude to be 0.005 to make the object 3D.
Tada! A 3D object!
Changing the object color to white might help you see it better.
With this 3D object, you can save it in a popular 3D format or do more manipulations on it.
This method is pretty straightforward and allows you to adjust a lot of individual parameters, like bitmap tracing.
Hope it helps!