Before printing an image, a drawing, in 3d, convert image to SVG and then to STL format.
This is a free converter where you can take a JPG file and convert it to SVG:
What is a SVG file ?
Svg (Scalable Vector Graphics) is an XML-based vector image format for two-dimensional graphics. The advantage is that you can modify image size without losing quality and detail. This vector format describes images as shapes, paths, text, and filter effects. Scaling the vector image preserves the shapes. This can be rendered at any resolution.