A preview image from a 3D part or CAD drawing can be probably saved using some kind of export function in CAD software. Such iges to jpg conversion is to used to create a plain static image of the model/part/drawing, which cannot be further edited as CAD file, just like a picture.
Open IGES file Open JPG fileA CAD and Gerber conversion software
A 3D product data optimalization software
A 3D CAD translation software