Yes you are violating the copyright. Even if you used a photo for reference, for instance you FREEHAND drew some fantasy image and used a photo of a bodybuilder as reference for the pose... if someone can compare your drawing and the source photo and reasonably say that yes you used that photo as regerence you are in violation of the copyright. So certainly tracing the image is a much more grievous violation. Would you ever get caught? Who knows. Even with reference you need to use it only to inform your 100% original drawing to be in the clear. I am not a lawyer but I did read https://www.amazon.com/Legal-Guide-Visual-Artist-Crawford/dp/1581157428 which is what I am paraphrasing here.