An image processing apparatus includes a first pattern detecting mechanism, a memory, and a pattern identity determining mechanism. The first pattern detecting mechanism detects a background dot pattern embedded in a background image included in image data of an original image from the image data. The memory stores an anti-copy background dot pattern. The pattern identity determining mechanism compares the detected background dot pattern with the anti-copy background dot pattern stored in the memory and determines that the detected background dot pattern is substantially identical to the anti-copy background dot pattern stored in the memory.