Convert Raster to Vector

Raster vs. Vector Art

Raster images are just a grid of colored pixels. If you have and HD image (1920 pixels by 1080 pixels), your image is basically 2k columns and 1k rows of colored dots. Photographs and most images from cameras and the web are raster images. Enlarging them too much can make them look blurry or pixelated. Common formats include JPG, PNG, GIF, and TIFF. Different image formats have different schemes for compressing the pixel grids so they take up less memory to store and transmit. Our canon printer likes raster images. Photoshop is the classic raster image editor. GIMP and Krita are the preferred FOSS software in our lab.

Vector images are made from mathematically defined lines, curves, and shapes. They can be resized without losing quality and are usually required for processes such as vinyl cutting and laser cutting. Common formats include SVG, AI, and EPS. SVG (scalable vector graphics) are just text files that hold the geometries of the image. Illustrator is the best known vector image editing software, while Inkscape is our preferred FOSS alternative in the lab. The xTool likes SVGs and works very well with Inkscape. The Roland also likes SVGs, and works well with Inkscape + custom extension (see our Roland page for details).

Raster to Vector

Trace bitmap in Inkscape

Inkscape has a built-in tool to convert raster images to vectors. It's called trace bitmap and it works pretty well for some types of images. It works best for line art and silhouettes, and similar. To get better results, you might want to manipulate your raster image in GIMP first, t odo things like remove background, change the contrast, delete certain colors, etc. I hate to admit it, but Illustrator's raster-to-vector tool is even more powerful than Inkscape's. Here's a guide on converting to vector in Inkscape.

If you are not getting good results and have access to Adobe, you might give it a shot. Our faculty have access to Creative Suite as well.

Trace by hand

Import your complex bitmap and then just use it as a guide to trace. Put it in its own layer and lock it. Use inkscape's shape, pen, and pencil tools to trace the parts that you want in your art.

AI Assist

Sometimes you can get a hand from a handy LLM. If I have an image that is generally what I want, I might use ChatGPT or another LLM to generate an image that is more suitable as a vector (so far, they are pretty terrible at actually making vector art directly). My prompt goes something like this:

[upload image] Hey, I want to engrave this image using an xTool P2S. I want to make a vector image similar to the one I uploaded. Can you make it a single color silhouette that would be easy to trace in Inkscape?

or

[upload image] I would like to cut a stencil of this on the Roland GS2-24. Can you make a version that is in the style of black and white line art with no islands that will fall out or details that are too small to weed/cut precisely? Thanks!