Scaling of imported jpg/png files

I am making a decal which will fit in a 0.5 mm pocket in a part designed in Sharp3D. The decal is provide to me by the artist as jpg/png file. I want to check the fit in the part, so imported it. My question is how does Shapr3D decide the scale of the imported graphic. It was made to a very specific dimension to fit the pocket, but when imported is twice as wide as expected. Sizing has failed at both 300 dpi and 400 dpi instances of the basic art.