In most cases a jpg to dst conversion represents attempts to create embroidery designs in Tajima format (.dst) from common JPEG pictures (.jpg, .jpeg). Considering DST format is pretty common and fairly supported in many embroidery designers, it will be easy to find a program with which you can make them. However, the real problem will be in making them from .jpg files.
You will need a program with decent "digitizing function", i.e. program capable of transforming raster data to vectors. Typically, this procedure works best for simple pictures like geometric shapes, logos and such. Using it on photos usually results in horrible result.
Updated: July 11, 2022